Strain Hardening Exponent n Calculator<\/title>\n <style>\n #ncalc-root {\n --ncalc-bg: #f4f6f8;\n --ncalc-panel: #ffffff;\n --ncalc-border: #d7dde5;\n --ncalc-text: #17212b;\n --ncalc-muted: #5b6775;\n --ncalc-accent: #116466;\n --ncalc-good: #0f7a3a;\n --ncalc-warn: #a15c00;\n color: var(--ncalc-text);\n background: var(--ncalc-bg);\n font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;\n line-height: 1.45;\n padding: 18px;\n }\n\n #ncalc-root,\n #ncalc-root * {\n box-sizing: border-box;\n }\n\n #ncalc-root .ncalc-wrap {\n max-width: 1440px;\n margin: 0 auto;\n }\n\n #ncalc-root .ncalc-section {\n background: var(--ncalc-panel);\n border: 1px solid var(--ncalc-border);\n border-radius: 10px;\n box-shadow: 0 1px 0 rgba(17, 24, 39, 0.03);\n padding: 14px;\n margin-bottom: 14px;\n }\n\n #ncalc-root h2 {\n margin: 0 0 12px;\n font-size: 1.05rem;\n color: var(--ncalc-text);\n }\n\n #ncalc-root .ncalc-form-grid {\n display: grid;\n gap: 12px;\n grid-template-columns: repeat(3, minmax(0, 1fr));\n }\n\n #ncalc-root .ncalc-field {\n display: grid;\n gap: 6px;\n align-content: start;\n }\n\n #ncalc-root .ncalc-field label {\n font-size: 0.82rem;\n color: var(--ncalc-muted);\n margin: 0;\n }\n\n #ncalc-root input,\n #ncalc-root select,\n #ncalc-root button {\n width: 100%;\n max-width: none;\n border-radius: 8px;\n border: 1px solid var(--ncalc-border);\n background: #ffffff;\n color: var(--ncalc-text);\n padding: 10px 11px;\n font: inherit;\n line-height: 1.3;\n min-height: 42px;\n }\n\n #ncalc-root input:disabled {\n background: #f2f4f7;\n color: #64748b;\n }\n\n #ncalc-root button {\n cursor: pointer;\n font-weight: 600;\n background: linear-gradient(135deg, var(--ncalc-accent), #145d8c);\n border-color: transparent;\n color: #ffffff;\n }\n\n #ncalc-root .ncalc-actions {\n display: flex;\n justify-content: center;\n margin-top: 12px;\n }\n\n #ncalc-root .ncalc-actions button {\n width: min(320px, 100%);\n min-width: 240px;\n }\n\n #ncalc-root .ncalc-table-wrap {\n overflow-x: auto;\n border: 1px solid var(--ncalc-border);\n border-radius: 10px;\n background: #ffffff;\n margin-top: 12px;\n }\n\n #ncalc-root table {\n width: 100%;\n min-width: 1160px;\n border-collapse: collapse;\n margin: 0;\n }\n\n #ncalc-root th,\n #ncalc-root td {\n border: 0;\n border-bottom: 1px solid #e7ecf2;\n padding: 8px;\n text-align: left;\n vertical-align: top;\n }\n\n #ncalc-root th {\n font-size: 0.82rem;\n color: var(--ncalc-muted);\n background: #f8fafc;\n font-weight: 600;\n }\n\n #ncalc-root td input {\n padding: 8px 9px;\n border-radius: 7px;\n min-height: 38px;\n }\n\n #ncalc-results {\n display: none;\n }\n\n #ncalc-results.ncalc-visible {\n display: block;\n }\n\n #ncalc-root .ncalc-result-grid {\n display: grid;\n gap: 12px;\n grid-template-columns: repeat(4, minmax(0, 1fr));\n }\n\n #ncalc-root .ncalc-result-card {\n border: 1px solid var(--ncalc-border);\n border-radius: 10px;\n background: #ffffff;\n padding: 12px;\n min-height: 88px;\n }\n\n #ncalc-root .ncalc-label {\n color: var(--ncalc-muted);\n font-size: 0.82rem;\n margin-bottom: 6px;\n }\n\n #ncalc-root .ncalc-value {\n font-size: 1.25rem;\n font-weight: 700;\n color: var(--ncalc-text);\n }\n\n #ncalc-root .ncalc-sub {\n color: var(--ncalc-muted);\n font-size: 0.84rem;\n margin-top: 4px;\n }\n\n #ncalc-root .ncalc-message-box {\n display: grid;\n gap: 8px;\n margin-top: 12px;\n }\n\n #ncalc-root .ncalc-message {\n border-left: 4px solid var(--ncalc-accent);\n background: #f7fbfc;\n border-radius: 8px;\n padding: 10px 12px;\n font-size: 0.92rem;\n }\n\n #ncalc-root .ncalc-message.good {\n border-left-color: var(--ncalc-good);\n }\n\n #ncalc-root .ncalc-message.warn {\n border-left-color: var(--ncalc-warn);\n }\n\n @media (max-width: 1180px) {\n #ncalc-root .ncalc-form-grid,\n #ncalc-root .ncalc-result-grid {\n grid-template-columns: 1fr;\n }\n\n #ncalc-root table {\n min-width: 1040px;\n }\n }\n <\/style>\n<\/head>\n<body>\n <div id=\"ncalc-root\">\n <div class=\"ncalc-wrap\">\n <section class=\"ncalc-section\">\n <h2>Inputs<\/h2>\n <div class=\"ncalc-form-grid\">\n <div class=\"ncalc-field\">\n <label for=\"ncalc-mode\">Calculation mode<\/label>\n <select id=\"ncalc-mode\">\n <option value=\"regression\">Multi-Point Regression<\/option>\n <option value=\"twoPoint\">Two-Point n-Value Calculation<\/option>\n <option value=\"engineering\">Engineering-to-True Data Conversion<\/option>\n <option value=\"comparison\">Material Comparison<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-unit-system\">Unit system<\/label>\n <select id=\"ncalc-unit-system\">\n <option value=\"metric\">Metric<\/option>\n <option value=\"imperial\">Imperial<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-stress-unit\">Stress \/ E unit<\/label>\n <select id=\"ncalc-stress-unit\"><\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-strain-format\">Strain format<\/label>\n <select id=\"ncalc-strain-format\">\n <option value=\"decimal\">Decimal<\/option>\n <option value=\"percent\">Percent<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-material-preset\">Material preset<\/label>\n <select id=\"ncalc-material-preset\"><\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-material-name\">Material name<\/label>\n <input id=\"ncalc-material-name\" type=\"text\" value=\"Low Carbon Steel\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-youngs-modulus\">Young’s modulus<\/label>\n <input id=\"ncalc-youngs-modulus\" type=\"number\" step=\"any\" value=\"200000\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-stress-type\">Stress data type<\/label>\n <select id=\"ncalc-stress-type\">\n <option value=\"trueStress\">True Stress<\/option>\n <option value=\"engineeringStress\">Engineering Stress<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-strain-type\">Strain data type<\/label>\n <select id=\"ncalc-strain-type\">\n <option value=\"truePlastic\">True Plastic Strain<\/option>\n <option value=\"trueTotal\">True Total Strain<\/option>\n <option value=\"engineeringStrain\">Engineering Strain<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-necking-onset\">Necking onset<\/label>\n <input id=\"ncalc-necking-onset\" type=\"number\" step=\"any\" value=\"0.18\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-range-min\">Min plastic strain<\/label>\n <input id=\"ncalc-range-min\" type=\"number\" step=\"any\" value=\"0.01\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-range-max\">Max plastic strain<\/label>\n <input id=\"ncalc-range-max\" type=\"number\" step=\"any\" value=\"0.20\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-prediction-strain\">Prediction strain<\/label>\n <input id=\"ncalc-prediction-strain\" type=\"number\" step=\"any\" value=\"0.10\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-comparison-strain\">Common comparison strain<\/label>\n <input id=\"ncalc-comparison-strain\" type=\"number\" step=\"any\" value=\"0.10\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-inverse-stress\">Known true stress for inverse strain<\/label>\n <input id=\"ncalc-inverse-stress\" type=\"number\" step=\"any\" value=\"350\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-good-threshold\">Good fit R^2<\/label>\n <input id=\"ncalc-good-threshold\" type=\"number\" step=\"any\" value=\"0.98\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-moderate-threshold\">Moderate fit R^2<\/label>\n <input id=\"ncalc-moderate-threshold\" type=\"number\" step=\"any\" value=\"0.95\">\n <\/div>\n <\/div>\n\n <div class=\"ncalc-table-wrap\">\n <table id=\"ncalc-data-table\">\n <thead>\n <tr>\n <th>Point<\/th>\n <th>Engineering Strain<\/th>\n <th>Engineering Stress<\/th>\n <th>True Strain<\/th>\n <th>True Stress<\/th>\n <th>True Plastic Strain<\/th>\n <th>ln(True Plastic Strain)<\/th>\n <th>ln(True Stress)<\/th>\n <\/tr>\n <\/thead>\n <tbody><\/tbody>\n <\/table>\n <\/div>\n\n <div class=\"ncalc-actions\">\n <button id=\"ncalc-calculate\" type=\"button\">Calculate<\/button>\n <\/div>\n <\/section>\n\n <section class=\"ncalc-section\" id=\"ncalc-results\">\n <h2>Results<\/h2>\n <div class=\"ncalc-result-grid\">\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Strain hardening exponent n<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-n\">—<\/div>\n <div class=\"ncalc-sub\">Dimensionless<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Strength coefficient K<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-k\">—<\/div>\n <div class=\"ncalc-sub\" id=\"ncalc-out-k-unit\">—<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Regression R^2<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-r2\">—<\/div>\n <div class=\"ncalc-sub\" id=\"ncalc-out-fit\">Fit quality pending<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Intercept ln(K)<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-intercept\">—<\/div>\n <div class=\"ncalc-sub\">Regression intercept<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Valid points<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-count\">—<\/div>\n <div class=\"ncalc-sub\" id=\"ncalc-out-range\">Selected strain range pending<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Predicted stress<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-pred-stress\">—<\/div>\n <div class=\"ncalc-sub\">At chosen plastic strain<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Inverse strain<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-inv-strain\">—<\/div>\n <div class=\"ncalc-sub\">From chosen stress<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Uniform true strain reference<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-uniform\">—<\/div>\n <div class=\"ncalc-sub\">Idealized Considere reference<\/div>\n <\/div>\n <\/div>\n <div class=\"ncalc-message-box\" id=\"ncalc-message-box\"><\/div>\n <\/section>\n <\/div>\n <\/div>\n\n <script>\n (function () {\n \"use strict\";\n\n function both(a, b) {\n return a ? b : a;\n }\n\n var presets = {\n metric: [\n { name: \"Low Carbon Steel\", e: 200000 },\n { name: \"High Strength Steel\", e: 210000 },\n { name: \"Stainless Steel\", e: 193000 },\n { name: \"Aluminum Alloy\", e: 70000 },\n { name: \"Copper Alloy\", e: 117000 },\n { name: \"Brass\", e: 100000 },\n { name: \"Titanium Alloy\", e: 116000 },\n { name: \"Custom Material\", e: 0 }\n ],\n imperial: [\n { name: \"Low Carbon Steel\", e: 29000 },\n { name: \"High Strength Steel\", e: 30500 },\n { name: \"Stainless Steel\", e: 28000 },\n { name: \"Aluminum Alloy\", e: 10000 },\n { name: \"Copper Alloy\", e: 17000 },\n { name: \"Brass\", e: 14500 },\n { name: \"Titanium Alloy\", e: 16800 },\n { name: \"Custom Material\", e: 0 }\n ]\n };\n\n var stressUnitOptions = {\n metric: [\"MPa\", \"GPa\"],\n imperial: [\"psi\", \"ksi\"]\n };\n var unitFactors = {\n MPa: 1,\n GPa: 1000,\n psi: 0.006894757,\n ksi: 6.894757\n };\n var defaultRows = [\n { truePlastic: 0.02, trueStress: 350 },\n { truePlastic: 0.05, trueStress: 420 },\n { truePlastic: 0.10, trueStress: 485 },\n { truePlastic: 0.15, trueStress: 525 },\n { truePlastic: 0.20, trueStress: 555 }\n ];\n\n var root = document.getElementById(\"ncalc-root\");\n if (!root) return;\n\n function byId(id) {\n return root.querySelector(\"#\" + id);\n }\n\n var els = {\n mode: byId(\"ncalc-mode\"),\n unitSystem: byId(\"ncalc-unit-system\"),\n stressUnit: byId(\"ncalc-stress-unit\"),\n strainFormat: byId(\"ncalc-strain-format\"),\n materialPreset: byId(\"ncalc-material-preset\"),\n materialName: byId(\"ncalc-material-name\"),\n youngsModulus: byId(\"ncalc-youngs-modulus\"),\n stressType: byId(\"ncalc-stress-type\"),\n strainType: byId(\"ncalc-strain-type\"),\n neckingOnset: byId(\"ncalc-necking-onset\"),\n rangeMin: byId(\"ncalc-range-min\"),\n rangeMax: byId(\"ncalc-range-max\"),\n predictionStrain: byId(\"ncalc-prediction-strain\"),\n comparisonStrain: byId(\"ncalc-comparison-strain\"),\n inverseStress: byId(\"ncalc-inverse-stress\"),\n goodThreshold: byId(\"ncalc-good-threshold\"),\n moderateThreshold: byId(\"ncalc-moderate-threshold\"),\n calcBtn: byId(\"ncalc-calculate\"),\n dataBody: root.querySelector(\"#ncalc-data-table tbody\"),\n outN: byId(\"ncalc-out-n\"),\n outK: byId(\"ncalc-out-k\"),\n outR2: byId(\"ncalc-out-r2\"),\n outIntercept: byId(\"ncalc-out-intercept\"),\n outCount: byId(\"ncalc-out-count\"),\n outRange: byId(\"ncalc-out-range\"),\n outFit: byId(\"ncalc-out-fit\"),\n outPredStress: byId(\"ncalc-out-pred-stress\"),\n outInvStrain: byId(\"ncalc-out-inv-strain\"),\n outUniform: byId(\"ncalc-out-uniform\"),\n outKUnit: byId(\"ncalc-out-k-unit\"),\n messageBox: byId(\"ncalc-message-box\"),\n resultsSection: byId(\"ncalc-results\")\n };\n\n var state = {\n lastStressUnit: \"MPa\",\n lastStrainPercent: false\n };\n\n function formatNumber(value, digits) {\n var abs;\n digits = typeof digits === \"number\" ? digits : 4;\n if (!isFinite(value)) return \"--\";\n abs = Math.abs(value);\n if (abs === 0) return \"0\";\n if (abs >= 1000) return value.toFixed(1);\n if (abs >= 100) return value.toFixed(2);\n if (abs >= 10) return value.toFixed(3);\n return value.toFixed(digits);\n }\n\n function parseValue(raw) {\n var cleaned;\n var n;\n if (raw === \"\" || raw === null || typeof raw === \"undefined\") return null;\n cleaned = String(raw).trim().replace(\/%$\/, \"\");\n if (cleaned === \"\") return null;\n n = Number(cleaned);\n return isFinite(n) ? n : null;\n }\n\n function isPercent() {\n return els.strainFormat.value === \"percent\";\n }\n\n function fromDecimalStrain(value) {\n if (!isFinite(value)) return \"\";\n return isPercent() ? value * 100 : value;\n }\n\n function currentStressUnit() {\n return els.stressUnit.value || (els.unitSystem.value === \"metric\" ? \"MPa\" : \"ksi\");\n }\n\n function stressToMPa(value) {\n return parseFloat(value) * unitFactors[currentStressUnit()];\n }\n\n function mpaToStress(value) {\n return value \/ unitFactors[currentStressUnit()];\n }\n\n function currentE() {\n return stressToMPa(els.youngsModulus.value);\n }\n\n function showResults() {\n els.resultsSection.className = \"ncalc-section ncalc-visible\";\n }\n\n function hideResults() {\n els.resultsSection.className = \"ncalc-section\";\n }\n\n function addMessage(type, text) {\n var div = document.createElement(\"div\");\n div.className = \"ncalc-message \" + type;\n div.appendChild(document.createTextNode(text));\n els.messageBox.appendChild(div);\n }\n\n function clearMessages() {\n els.messageBox.innerHTML = \"\";\n }\n\n function getFieldValue(tr, field) {\n var input = tr.querySelector('[data-field=\"' + field + '\"]');\n return input ? input.value : \"\";\n }\n\n function createRow(data) {\n var tr = document.createElement(\"tr\");\n var fields = [\n [\"engStrain\", data.engStrain || \"\"],\n [\"engStress\", data.engStress || \"\"],\n [\"trueStrain\", data.trueStrain || \"\"],\n [\"trueStress\", data.trueStress || \"\"],\n [\"truePlastic\", data.truePlastic || \"\"],\n [\"lnPlastic\", \"\"],\n [\"lnStress\", \"\"]\n ];\n var tdIndex = document.createElement(\"td\");\n tdIndex.className = \"ncalc-row-index\";\n tr.appendChild(tdIndex);\n fields.forEach(function (field) {\n var td = document.createElement(\"td\");\n var input = document.createElement(\"input\");\n input.setAttribute(\"data-field\", field[0]);\n input.type = field[0] === \"lnPlastic\" || field[0] === \"lnStress\" ? \"text\" : \"number\";\n input.step = \"any\";\n input.value = field[1];\n if (field[0] === \"lnPlastic\" || field[0] === \"lnStress\") input.readOnly = true;\n input.addEventListener(\"input\", hideResults);\n input.addEventListener(\"paste\", handleTablePaste);\n td.appendChild(input);\n tr.appendChild(td);\n });\n return tr;\n }\n\n function setRows(rows) {\n els.dataBody.innerHTML = \"\";\n rows.forEach(function (row) {\n els.dataBody.appendChild(createRow(row));\n });\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr, idx) {\n tr.querySelector(\".ncalc-row-index\").appendChild(document.createTextNode(String(idx + 1)));\n });\n }\n\n function populatePresetSelect() {\n var list = presets[els.unitSystem.value];\n els.materialPreset.innerHTML = \"\";\n list.forEach(function (item) {\n var opt = document.createElement(\"option\");\n opt.value = item.name;\n opt.appendChild(document.createTextNode(item.name));\n els.materialPreset.appendChild(opt);\n });\n }\n\n function updateUnitOptions() {\n els.stressUnit.innerHTML = \"\";\n stressUnitOptions[els.unitSystem.value].forEach(function (unit) {\n var opt = document.createElement(\"option\");\n opt.value = unit;\n opt.appendChild(document.createTextNode(unit));\n els.stressUnit.appendChild(opt);\n });\n els.stressUnit.value = els.unitSystem.value === \"metric\" ? \"MPa\" : \"ksi\";\n }\n\n function applyPreset() {\n var list = presets[els.unitSystem.value];\n var preset = null;\n list.forEach(function (item) {\n if (item.name === els.materialPreset.value) preset = item;\n });\n if (!preset) return;\n els.materialName.value = preset.name;\n els.youngsModulus.value = preset.e ? formatNumber(preset.e, 3).replace(\/\\.?0+$\/, \"\") : \"\";\n }\n\n function convertDisplayedStressFields(fromUnit, toUnit) {\n var factor;\n if (!fromUnit || !toUnit || fromUnit === toUnit) return;\n factor = unitFactors[fromUnit] \/ unitFactors[toUnit];\n [els.youngsModulus, els.inverseStress].forEach(function (field) {\n var val = parseFloat(field.value);\n if (isFinite(val)) field.value = formatNumber(val * factor, 4);\n });\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr) {\n [\"engStress\", \"trueStress\"].forEach(function (fieldName) {\n var input = tr.querySelector('[data-field=\"' + fieldName + '\"]');\n var val = input ? parseFloat(input.value) : NaN;\n if (both(input, isFinite(val))) input.value = formatNumber(val * factor, 4);\n });\n });\n }\n\n function convertDisplayedStrainFields(fromPercent, toPercent) {\n var factor;\n if (fromPercent === toPercent) return;\n factor = fromPercent ? 0.01 : 100;\n [els.neckingOnset, els.rangeMin, els.rangeMax, els.predictionStrain, els.comparisonStrain].forEach(function (field) {\n var val = parseFloat(field.value);\n if (isFinite(val)) field.value = formatNumber(val * factor, 5);\n });\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr) {\n [\"engStrain\", \"trueStrain\", \"truePlastic\"].forEach(function (fieldName) {\n var input = tr.querySelector('[data-field=\"' + fieldName + '\"]');\n var val = input ? parseFloat(input.value) : NaN;\n if (both(input, isFinite(val))) input.value = formatNumber(val * factor, 6);\n });\n });\n }\n\n function handleTablePaste(event) {\n var text = event.clipboardData ? event.clipboardData.getData(\"text\") : \"\";\n var startCell;\n var startRow;\n var rows;\n var tableRows;\n var rowIndex;\n var fieldOrder = [\"engStrain\", \"engStress\", \"trueStrain\", \"trueStress\", \"truePlastic\"];\n var startInput;\n var startIndex;\n if (!text || both(text.indexOf(\"\\n\") === -1, text.indexOf(\"\\t\") === -1)) return;\n event.preventDefault();\n startCell = event.target.closest(\"td\");\n startRow = event.target.closest(\"tr\");\n rows = text.trim().split(\/\\r?\\n\/).map(function (line) {\n return line.split(\/[\\t,;]+\/);\n });\n tableRows = Array.prototype.slice.call(els.dataBody.querySelectorAll(\"tr\"));\n rowIndex = tableRows.indexOf(startRow);\n startInput = startCell ? startCell.querySelector(\"input[data-field]\") : null;\n startIndex = fieldOrder.indexOf(startInput ? startInput.getAttribute(\"data-field\") : \"\");\n rows.forEach(function (values, r) {\n var targetRow = tableRows[rowIndex + r];\n if (!targetRow) return;\n values.forEach(function (value, c) {\n var field = fieldOrder[(startIndex >= 0 ? startIndex : 0) + c];\n var input = targetRow.querySelector('[data-field=\"' + field + '\"]');\n if (input) input.value = value.trim();\n });\n });\n hideResults();\n }\n\n function classifyFit(r2) {\n var good = parseFloat(els.goodThreshold.value) || 0.98;\n var moderate = parseFloat(els.moderateThreshold.value) || 0.95;\n if (!isFinite(r2)) return { label: \"Pending\", cls: \"\" };\n if (r2 >= good) return { label: \"Good\", cls: \"good\" };\n if (r2 >= moderate) return { label: \"Moderate\", cls: \"warn\" };\n return { label: \"Poor\", cls: \"warn\" };\n }\n\n function convertRow(row) {\n var strainType = els.strainType.value;\n var stressType = els.stressType.value;\n var eModulus = currentE();\n var engStrain = parseValue(row.engStrain);\n var engStress = parseValue(row.engStress);\n var trueStrain = parseValue(row.trueStrain);\n var trueStress = parseValue(row.trueStress);\n var truePlastic = parseValue(row.truePlastic);\n\n if (!isFinite(eModulus) || eModulus <= 0) return { valid: false, warnings: [\"Young's modulus must be greater than zero.\"] };\n\n if (strainType === \"engineeringStrain\") {\n if (engStrain === null) return { valid: false, warnings: [] };\n trueStrain = Math.log(1 + engStrain);\n } else if (strainType === \"trueTotal\") {\n if (both(trueStrain === null, engStrain !== null)) trueStrain = Math.log(1 + engStrain);\n } else if (strainType === \"truePlastic\") {\n if (truePlastic === null) return { valid: false, warnings: [] };\n }\n\n if (stressType === \"engineeringStress\") {\n if (engStress === null) return { valid: false, warnings: [] };\n if (strainType === \"engineeringStrain\") {\n trueStress = engStress * (1 + engStrain);\n } else if (both(strainType === \"trueTotal\", trueStrain !== null)) {\n engStrain = Math.exp(trueStrain) - 1;\n trueStress = engStress * (1 + engStrain);\n } else if (both(strainType === \"truePlastic\", engStrain !== null)) {\n trueStress = engStress * (1 + engStrain);\n } else {\n return { valid: false, warnings: [] };\n }\n } else if (trueStress === null) {\n return { valid: false, warnings: [] };\n }\n\n if (trueStress === null || !isFinite(trueStress) || trueStress <= 0) {\n return { valid: false, warnings: [\"True stress must be greater than zero.\"] };\n }\n\n if (strainType === \"truePlastic\") {\n if (!isFinite(truePlastic) || truePlastic <= 0) {\n return { valid: false, warnings: [\"True plastic strain must be greater than zero.\"] };\n }\n } else {\n if (!isFinite(trueStrain)) return { valid: false, warnings: [] };\n truePlastic = trueStrain - trueStress \/ eModulus;\n }\n\n if (!isFinite(truePlastic) || truePlastic <= 0) {\n return { valid: false, warnings: [\"Negative or zero plastic strain after conversion.\"] };\n }\n\n return {\n valid: true,\n engStrain: engStrain,\n engStress: engStress,\n trueStrain: trueStrain,\n trueStress: trueStress,\n truePlastic: truePlastic,\n lnPlastic: Math.log(truePlastic),\n lnStress: Math.log(trueStress),\n warnings: []\n };\n }\n\n function regress(points) {\n var n = points.length;\n var meanX = points.reduce(function (s, p) { return s + p.x; }, 0) \/ n;\n var meanY = points.reduce(function (s, p) { return s + p.y; }, 0) \/ n;\n var sxx = points.reduce(function (s, p) { return s + Math.pow(p.x - meanX, 2); }, 0);\n var sxy = points.reduce(function (s, p) { return s + (p.x - meanX) * (p.y - meanY); }, 0);\n var slope = sxy \/ sxx;\n var intercept = meanY - slope * meanX;\n var predictions = points.map(function (p) { return intercept + slope * p.x; });\n var ssRes = points.reduce(function (s, p, i) { return s + Math.pow(p.y - predictions[i], 2); }, 0);\n var ssTot = points.reduce(function (s, p) { return s + Math.pow(p.y - meanY, 2); }, 0);\n var r2 = ssTot === 0 ? 1 : 1 - ssRes \/ ssTot;\n return { slope: slope, intercept: intercept, r2: r2 };\n }\n\n function renderTablePreview(rows) {\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr, idx) {\n var row = rows[idx];\n var lnPlastic = tr.querySelector('[data-field=\"lnPlastic\"]');\n var lnStress = tr.querySelector('[data-field=\"lnStress\"]');\n if (both(row, row.valid)) {\n if (lnPlastic) lnPlastic.value = formatNumber(row.lnPlastic, 6);\n if (lnStress) lnStress.value = formatNumber(row.lnStress, 6);\n } else {\n if (lnPlastic) lnPlastic.value = \"\";\n if (lnStress) lnStress.value = \"\";\n }\n });\n }\n\n function calculate() {\n var rawRows;\n var conversionRows;\n var warnings = [];\n var validRows;\n var min;\n var max;\n var filtered;\n var points;\n var twoPointMode;\n var requiredPoints;\n var result = null;\n var n;\n var intercept;\n var kValue;\n var fit;\n var predStrain;\n var invStress;\n var predictedStress;\n var inverseStrain;\n\n showResults();\n clearMessages();\n\n rawRows = Array.prototype.map.call(els.dataBody.querySelectorAll(\"tr\"), function (tr) {\n return {\n engStrain: getFieldValue(tr, \"engStrain\"),\n engStress: getFieldValue(tr, \"engStress\"),\n trueStrain: getFieldValue(tr, \"trueStrain\"),\n trueStress: getFieldValue(tr, \"trueStress\"),\n truePlastic: getFieldValue(tr, \"truePlastic\")\n };\n });\n\n conversionRows = rawRows.map(convertRow);\n conversionRows.forEach(function (row) {\n row.warnings.forEach(function (warning) {\n warnings.push(warning);\n });\n });\n renderTablePreview(conversionRows);\n\n validRows = conversionRows.filter(function (row) {\n return row.valid;\n });\n min = parseValue(els.rangeMin.value);\n max = parseValue(els.rangeMax.value);\n if (both(both(min !== null, max !== null), min > max)) {\n var temp = min;\n min = max;\n max = temp;\n }\n\n filtered = validRows.filter(function (row) {\n if (both(min !== null, row.truePlastic < min)) return false;\n if (both(max !== null, row.truePlastic > max)) return false;\n return true;\n });\n\n points = filtered.map(function (row) {\n return { x: Math.log(row.truePlastic), y: Math.log(row.trueStress), row: row };\n });\n twoPointMode = els.mode.value === \"twoPoint\";\n requiredPoints = twoPointMode ? 2 : 3;\n if (points.length < requiredPoints) {\n warnings.push(twoPointMode ? \"Two-point calculation requires at least two valid points.\" : \"Regression requires at least three valid points.\");\n }\n\n if (both(twoPointMode, points.length >= 2)) {\n result = regress(points);\n n = Math.log(filtered[1].trueStress \/ filtered[0].trueStress) \/ Math.log(filtered[1].truePlastic \/ filtered[0].truePlastic);\n intercept = Math.log(filtered[0].trueStress) - n * Math.log(filtered[0].truePlastic);\n result = { slope: n, intercept: intercept, r2: result.r2 };\n } else if (both(!twoPointMode, points.length >= 3)) {\n result = regress(points);\n }\n\n if (result) {\n n = result.slope;\n kValue = Math.exp(result.intercept);\n fit = classifyFit(result.r2);\n predStrain = parseValue(els.predictionStrain.value);\n invStress = parseValue(els.inverseStress.value);\n predictedStress = both(predStrain, predStrain > 0) ? kValue * Math.pow(predStrain, n) : null;\n inverseStrain = both(both(invStress, invStress > 0), n !== 0) ? Math.pow(invStress \/ kValue, 1 \/ n) : null;\n\n els.outN.textContent = formatNumber(n, 5);\n els.outK.textContent = formatNumber(mpaToStress(kValue), 4);\n els.outR2.textContent = formatNumber(result.r2, 4);\n els.outIntercept.textContent = formatNumber(result.intercept, 5);\n els.outCount.textContent = String(filtered.length);\n els.outRange.textContent = \"Used \" + (min !== null ? fromDecimalStrain(min) : \"auto\") + \" to \" + (max !== null ? fromDecimalStrain(max) : \"auto\") + \" (\" + els.strainFormat.value + \")\";\n els.outFit.textContent = \"Fit quality: \" + fit.label;\n els.outKUnit.textContent = currentStressUnit();\n els.outPredStress.textContent = predictedStress !== null ? formatNumber(mpaToStress(predictedStress), 4) + \" \" + currentStressUnit() : \"--\";\n els.outInvStrain.textContent = inverseStrain !== null ? formatNumber(inverseStrain, 5) : \"--\";\n els.outUniform.textContent = formatNumber(n, 5) + \" \/ \" + formatNumber(Math.exp(n) - 1, 5);\n } else {\n els.outN.textContent = \"--\";\n els.outK.textContent = \"--\";\n els.outR2.textContent = \"--\";\n els.outIntercept.textContent = \"--\";\n els.outCount.textContent = \"--\";\n els.outRange.textContent = \"Selected strain range pending\";\n els.outFit.textContent = \"Fit quality pending\";\n els.outKUnit.textContent = currentStressUnit();\n els.outPredStress.textContent = \"--\";\n els.outInvStrain.textContent = \"--\";\n els.outUniform.textContent = \"--\";\n }\n\n warnings.filter(function (value, index, array) {\n return array.indexOf(value) === index;\n }).forEach(function (warning) {\n addMessage(\"warn\", warning);\n });\n if (both(!warnings.length, result)) addMessage(\"good\", \"Computed n = \" + formatNumber(n, 5) + \" with \" + filtered.length + \" valid points.\");\n }\n\n function wireEvents() {\n var controls = [\n els.mode, els.unitSystem, els.stressUnit, els.strainFormat, els.materialPreset, els.materialName,\n els.youngsModulus, els.stressType, els.strainType, els.neckingOnset, els.rangeMin, els.rangeMax,\n els.predictionStrain, els.comparisonStrain, els.inverseStress, els.goodThreshold, els.moderateThreshold\n ];\n controls.forEach(function (el) {\n el.addEventListener(\"input\", function () {\n var oldUnit;\n var newUnit;\n var fromPercent;\n var toPercent;\n hideResults();\n if (el === els.unitSystem) {\n oldUnit = state.lastStressUnit || currentStressUnit();\n updateUnitOptions();\n populatePresetSelect();\n applyPreset();\n newUnit = currentStressUnit();\n if (oldUnit !== newUnit) convertDisplayedStressFields(oldUnit, newUnit);\n state.lastStressUnit = newUnit;\n }\n if (el === els.stressUnit) {\n oldUnit = state.lastStressUnit || currentStressUnit();\n newUnit = currentStressUnit();\n if (oldUnit !== newUnit) convertDisplayedStressFields(oldUnit, newUnit);\n state.lastStressUnit = newUnit;\n }\n if (el === els.strainFormat) {\n fromPercent = state.lastStrainPercent || false;\n toPercent = isPercent();\n if (fromPercent !== toPercent) convertDisplayedStrainFields(fromPercent, toPercent);\n state.lastStrainPercent = toPercent;\n }\n if (el === els.materialPreset) applyPreset();\n });\n });\n els.calcBtn.addEventListener(\"click\", calculate);\n }\n\n function init() {\n updateUnitOptions();\n populatePresetSelect();\n setRows(defaultRows);\n els.materialPreset.value = \"Low Carbon Steel\";\n applyPreset();\n els.materialName.value = \"Low Carbon Steel\";\n els.stressType.value = \"trueStress\";\n els.strainType.value = \"truePlastic\";\n els.youngsModulus.value = 200000;\n state.lastStressUnit = currentStressUnit();\n state.lastStrainPercent = isPercent();\n wireEvents();\n hideResults();\n }\n\n init();\n }());\n <\/script>\n<\/body>\n<\/html>\n","protected":false},"excerpt":{"rendered":"<p>The Strain Hardening Exponent n Calculator is a practical engineering tool designed to calculate the strain hardening exponent (n-value) from tensile test data using the…<\/p>","protected":false},"author":2,"featured_media":24836,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"pmpro_default_level":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[8647],"tags":[8696,8697,8698,8682],"class_list":["post-24835","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-materials-science-and-properties","tag-hollomon-equation","tag-material-formability","tag-strain-hardening","tag-tensile-testing","pmpro-has-access"],"acf":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/www.mechstream.com\/wp-content\/uploads\/2026\/09\/Strain-Hardening-Exponent-n-Calculator.png","_links":{"self":[{"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/posts\/24835","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/comments?post=24835"}],"version-history":[{"count":0,"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/posts\/24835\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/media\/24836"}],"wp:attachment":[{"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/media?parent=24835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/categories?post=24835"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mechstream.com\/fr\/wp-json\/wp\/v2\/tags?post=24835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

{"id":24835,"date":"2026-09-08T00:31:27","date_gmt":"2026-09-08T00:31:27","guid":{"rendered":"https:\/\/www.mechstream.com\/?p=24835"},"modified":"2026-09-08T00:49:21","modified_gmt":"2026-09-08T00:49:21","slug":"strain-hardening-exponent-n-calculator","status":"publish","type":"post","link":"https:\/\/www.mechstream.com\/fr\/strain-hardening-exponent-n-calculator\/","title":{"rendered":"Strain Hardening Exponent n Calculator"},"content":{"rendered":"\n

The Strain Hardening Exponent n Calculator<\/strong> is a practical engineering tool designed to calculate the strain hardening exponent (n-value) from tensile test data using the Hollomon equation. It helps engineers analyze true stress, true plastic strain, strength coefficient, and material work-hardening behavior. The Strain Hardening Exponent n Calculator is useful for sheet metal forming, material characterization, tensile testing, stamping analysis, and comparing the formability of different engineering materials.<\/p>\n\n\n\n\n\n\n \n \n Strain Hardening Exponent n Calculator<\/title>\n <style>\n #ncalc-root {\n --ncalc-bg: #f4f6f8;\n --ncalc-panel: #ffffff;\n --ncalc-border: #d7dde5;\n --ncalc-text: #17212b;\n --ncalc-muted: #5b6775;\n --ncalc-accent: #116466;\n --ncalc-good: #0f7a3a;\n --ncalc-warn: #a15c00;\n color: var(--ncalc-text);\n background: var(--ncalc-bg);\n font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;\n line-height: 1.45;\n padding: 18px;\n }\n\n #ncalc-root,\n #ncalc-root * {\n box-sizing: border-box;\n }\n\n #ncalc-root .ncalc-wrap {\n max-width: 1440px;\n margin: 0 auto;\n }\n\n #ncalc-root .ncalc-section {\n background: var(--ncalc-panel);\n border: 1px solid var(--ncalc-border);\n border-radius: 10px;\n box-shadow: 0 1px 0 rgba(17, 24, 39, 0.03);\n padding: 14px;\n margin-bottom: 14px;\n }\n\n #ncalc-root h2 {\n margin: 0 0 12px;\n font-size: 1.05rem;\n color: var(--ncalc-text);\n }\n\n #ncalc-root .ncalc-form-grid {\n display: grid;\n gap: 12px;\n grid-template-columns: repeat(3, minmax(0, 1fr));\n }\n\n #ncalc-root .ncalc-field {\n display: grid;\n gap: 6px;\n align-content: start;\n }\n\n #ncalc-root .ncalc-field label {\n font-size: 0.82rem;\n color: var(--ncalc-muted);\n margin: 0;\n }\n\n #ncalc-root input,\n #ncalc-root select,\n #ncalc-root button {\n width: 100%;\n max-width: none;\n border-radius: 8px;\n border: 1px solid var(--ncalc-border);\n background: #ffffff;\n color: var(--ncalc-text);\n padding: 10px 11px;\n font: inherit;\n line-height: 1.3;\n min-height: 42px;\n }\n\n #ncalc-root input:disabled {\n background: #f2f4f7;\n color: #64748b;\n }\n\n #ncalc-root button {\n cursor: pointer;\n font-weight: 600;\n background: linear-gradient(135deg, var(--ncalc-accent), #145d8c);\n border-color: transparent;\n color: #ffffff;\n }\n\n #ncalc-root .ncalc-actions {\n display: flex;\n justify-content: center;\n margin-top: 12px;\n }\n\n #ncalc-root .ncalc-actions button {\n width: min(320px, 100%);\n min-width: 240px;\n }\n\n #ncalc-root .ncalc-table-wrap {\n overflow-x: auto;\n border: 1px solid var(--ncalc-border);\n border-radius: 10px;\n background: #ffffff;\n margin-top: 12px;\n }\n\n #ncalc-root table {\n width: 100%;\n min-width: 1160px;\n border-collapse: collapse;\n margin: 0;\n }\n\n #ncalc-root th,\n #ncalc-root td {\n border: 0;\n border-bottom: 1px solid #e7ecf2;\n padding: 8px;\n text-align: left;\n vertical-align: top;\n }\n\n #ncalc-root th {\n font-size: 0.82rem;\n color: var(--ncalc-muted);\n background: #f8fafc;\n font-weight: 600;\n }\n\n #ncalc-root td input {\n padding: 8px 9px;\n border-radius: 7px;\n min-height: 38px;\n }\n\n #ncalc-results {\n display: none;\n }\n\n #ncalc-results.ncalc-visible {\n display: block;\n }\n\n #ncalc-root .ncalc-result-grid {\n display: grid;\n gap: 12px;\n grid-template-columns: repeat(4, minmax(0, 1fr));\n }\n\n #ncalc-root .ncalc-result-card {\n border: 1px solid var(--ncalc-border);\n border-radius: 10px;\n background: #ffffff;\n padding: 12px;\n min-height: 88px;\n }\n\n #ncalc-root .ncalc-label {\n color: var(--ncalc-muted);\n font-size: 0.82rem;\n margin-bottom: 6px;\n }\n\n #ncalc-root .ncalc-value {\n font-size: 1.25rem;\n font-weight: 700;\n color: var(--ncalc-text);\n }\n\n #ncalc-root .ncalc-sub {\n color: var(--ncalc-muted);\n font-size: 0.84rem;\n margin-top: 4px;\n }\n\n #ncalc-root .ncalc-message-box {\n display: grid;\n gap: 8px;\n margin-top: 12px;\n }\n\n #ncalc-root .ncalc-message {\n border-left: 4px solid var(--ncalc-accent);\n background: #f7fbfc;\n border-radius: 8px;\n padding: 10px 12px;\n font-size: 0.92rem;\n }\n\n #ncalc-root .ncalc-message.good {\n border-left-color: var(--ncalc-good);\n }\n\n #ncalc-root .ncalc-message.warn {\n border-left-color: var(--ncalc-warn);\n }\n\n @media (max-width: 1180px) {\n #ncalc-root .ncalc-form-grid,\n #ncalc-root .ncalc-result-grid {\n grid-template-columns: 1fr;\n }\n\n #ncalc-root table {\n min-width: 1040px;\n }\n }\n <\/style>\n<\/head>\n<body>\n <div id=\"ncalc-root\">\n <div class=\"ncalc-wrap\">\n <section class=\"ncalc-section\">\n <h2>Inputs<\/h2>\n <div class=\"ncalc-form-grid\">\n <div class=\"ncalc-field\">\n <label for=\"ncalc-mode\">Calculation mode<\/label>\n <select id=\"ncalc-mode\">\n <option value=\"regression\">Multi-Point Regression<\/option>\n <option value=\"twoPoint\">Two-Point n-Value Calculation<\/option>\n <option value=\"engineering\">Engineering-to-True Data Conversion<\/option>\n <option value=\"comparison\">Material Comparison<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-unit-system\">Unit system<\/label>\n <select id=\"ncalc-unit-system\">\n <option value=\"metric\">Metric<\/option>\n <option value=\"imperial\">Imperial<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-stress-unit\">Stress \/ E unit<\/label>\n <select id=\"ncalc-stress-unit\"><\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-strain-format\">Strain format<\/label>\n <select id=\"ncalc-strain-format\">\n <option value=\"decimal\">Decimal<\/option>\n <option value=\"percent\">Percent<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-material-preset\">Material preset<\/label>\n <select id=\"ncalc-material-preset\"><\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-material-name\">Material name<\/label>\n <input id=\"ncalc-material-name\" type=\"text\" value=\"Low Carbon Steel\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-youngs-modulus\">Young’s modulus<\/label>\n <input id=\"ncalc-youngs-modulus\" type=\"number\" step=\"any\" value=\"200000\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-stress-type\">Stress data type<\/label>\n <select id=\"ncalc-stress-type\">\n <option value=\"trueStress\">True Stress<\/option>\n <option value=\"engineeringStress\">Engineering Stress<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-strain-type\">Strain data type<\/label>\n <select id=\"ncalc-strain-type\">\n <option value=\"truePlastic\">True Plastic Strain<\/option>\n <option value=\"trueTotal\">True Total Strain<\/option>\n <option value=\"engineeringStrain\">Engineering Strain<\/option>\n <\/select>\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-necking-onset\">Necking onset<\/label>\n <input id=\"ncalc-necking-onset\" type=\"number\" step=\"any\" value=\"0.18\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-range-min\">Min plastic strain<\/label>\n <input id=\"ncalc-range-min\" type=\"number\" step=\"any\" value=\"0.01\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-range-max\">Max plastic strain<\/label>\n <input id=\"ncalc-range-max\" type=\"number\" step=\"any\" value=\"0.20\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-prediction-strain\">Prediction strain<\/label>\n <input id=\"ncalc-prediction-strain\" type=\"number\" step=\"any\" value=\"0.10\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-comparison-strain\">Common comparison strain<\/label>\n <input id=\"ncalc-comparison-strain\" type=\"number\" step=\"any\" value=\"0.10\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-inverse-stress\">Known true stress for inverse strain<\/label>\n <input id=\"ncalc-inverse-stress\" type=\"number\" step=\"any\" value=\"350\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-good-threshold\">Good fit R^2<\/label>\n <input id=\"ncalc-good-threshold\" type=\"number\" step=\"any\" value=\"0.98\">\n <\/div>\n <div class=\"ncalc-field\">\n <label for=\"ncalc-moderate-threshold\">Moderate fit R^2<\/label>\n <input id=\"ncalc-moderate-threshold\" type=\"number\" step=\"any\" value=\"0.95\">\n <\/div>\n <\/div>\n\n <div class=\"ncalc-table-wrap\">\n <table id=\"ncalc-data-table\">\n <thead>\n <tr>\n <th>Point<\/th>\n <th>Engineering Strain<\/th>\n <th>Engineering Stress<\/th>\n <th>True Strain<\/th>\n <th>True Stress<\/th>\n <th>True Plastic Strain<\/th>\n <th>ln(True Plastic Strain)<\/th>\n <th>ln(True Stress)<\/th>\n <\/tr>\n <\/thead>\n <tbody><\/tbody>\n <\/table>\n <\/div>\n\n <div class=\"ncalc-actions\">\n <button id=\"ncalc-calculate\" type=\"button\">Calculate<\/button>\n <\/div>\n <\/section>\n\n <section class=\"ncalc-section\" id=\"ncalc-results\">\n <h2>Results<\/h2>\n <div class=\"ncalc-result-grid\">\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Strain hardening exponent n<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-n\">—<\/div>\n <div class=\"ncalc-sub\">Dimensionless<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Strength coefficient K<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-k\">—<\/div>\n <div class=\"ncalc-sub\" id=\"ncalc-out-k-unit\">—<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Regression R^2<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-r2\">—<\/div>\n <div class=\"ncalc-sub\" id=\"ncalc-out-fit\">Fit quality pending<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Intercept ln(K)<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-intercept\">—<\/div>\n <div class=\"ncalc-sub\">Regression intercept<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Valid points<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-count\">—<\/div>\n <div class=\"ncalc-sub\" id=\"ncalc-out-range\">Selected strain range pending<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Predicted stress<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-pred-stress\">—<\/div>\n <div class=\"ncalc-sub\">At chosen plastic strain<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Inverse strain<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-inv-strain\">—<\/div>\n <div class=\"ncalc-sub\">From chosen stress<\/div>\n <\/div>\n <div class=\"ncalc-result-card\">\n <div class=\"ncalc-label\">Uniform true strain reference<\/div>\n <div class=\"ncalc-value\" id=\"ncalc-out-uniform\">—<\/div>\n <div class=\"ncalc-sub\">Idealized Considere reference<\/div>\n <\/div>\n <\/div>\n <div class=\"ncalc-message-box\" id=\"ncalc-message-box\"><\/div>\n <\/section>\n <\/div>\n <\/div>\n\n <script>\n (function () {\n \"use strict\";\n\n function both(a, b) {\n return a ? b : a;\n }\n\n var presets = {\n metric: [\n { name: \"Low Carbon Steel\", e: 200000 },\n { name: \"High Strength Steel\", e: 210000 },\n { name: \"Stainless Steel\", e: 193000 },\n { name: \"Aluminum Alloy\", e: 70000 },\n { name: \"Copper Alloy\", e: 117000 },\n { name: \"Brass\", e: 100000 },\n { name: \"Titanium Alloy\", e: 116000 },\n { name: \"Custom Material\", e: 0 }\n ],\n imperial: [\n { name: \"Low Carbon Steel\", e: 29000 },\n { name: \"High Strength Steel\", e: 30500 },\n { name: \"Stainless Steel\", e: 28000 },\n { name: \"Aluminum Alloy\", e: 10000 },\n { name: \"Copper Alloy\", e: 17000 },\n { name: \"Brass\", e: 14500 },\n { name: \"Titanium Alloy\", e: 16800 },\n { name: \"Custom Material\", e: 0 }\n ]\n };\n\n var stressUnitOptions = {\n metric: [\"MPa\", \"GPa\"],\n imperial: [\"psi\", \"ksi\"]\n };\n var unitFactors = {\n MPa: 1,\n GPa: 1000,\n psi: 0.006894757,\n ksi: 6.894757\n };\n var defaultRows = [\n { truePlastic: 0.02, trueStress: 350 },\n { truePlastic: 0.05, trueStress: 420 },\n { truePlastic: 0.10, trueStress: 485 },\n { truePlastic: 0.15, trueStress: 525 },\n { truePlastic: 0.20, trueStress: 555 }\n ];\n\n var root = document.getElementById(\"ncalc-root\");\n if (!root) return;\n\n function byId(id) {\n return root.querySelector(\"#\" + id);\n }\n\n var els = {\n mode: byId(\"ncalc-mode\"),\n unitSystem: byId(\"ncalc-unit-system\"),\n stressUnit: byId(\"ncalc-stress-unit\"),\n strainFormat: byId(\"ncalc-strain-format\"),\n materialPreset: byId(\"ncalc-material-preset\"),\n materialName: byId(\"ncalc-material-name\"),\n youngsModulus: byId(\"ncalc-youngs-modulus\"),\n stressType: byId(\"ncalc-stress-type\"),\n strainType: byId(\"ncalc-strain-type\"),\n neckingOnset: byId(\"ncalc-necking-onset\"),\n rangeMin: byId(\"ncalc-range-min\"),\n rangeMax: byId(\"ncalc-range-max\"),\n predictionStrain: byId(\"ncalc-prediction-strain\"),\n comparisonStrain: byId(\"ncalc-comparison-strain\"),\n inverseStress: byId(\"ncalc-inverse-stress\"),\n goodThreshold: byId(\"ncalc-good-threshold\"),\n moderateThreshold: byId(\"ncalc-moderate-threshold\"),\n calcBtn: byId(\"ncalc-calculate\"),\n dataBody: root.querySelector(\"#ncalc-data-table tbody\"),\n outN: byId(\"ncalc-out-n\"),\n outK: byId(\"ncalc-out-k\"),\n outR2: byId(\"ncalc-out-r2\"),\n outIntercept: byId(\"ncalc-out-intercept\"),\n outCount: byId(\"ncalc-out-count\"),\n outRange: byId(\"ncalc-out-range\"),\n outFit: byId(\"ncalc-out-fit\"),\n outPredStress: byId(\"ncalc-out-pred-stress\"),\n outInvStrain: byId(\"ncalc-out-inv-strain\"),\n outUniform: byId(\"ncalc-out-uniform\"),\n outKUnit: byId(\"ncalc-out-k-unit\"),\n messageBox: byId(\"ncalc-message-box\"),\n resultsSection: byId(\"ncalc-results\")\n };\n\n var state = {\n lastStressUnit: \"MPa\",\n lastStrainPercent: false\n };\n\n function formatNumber(value, digits) {\n var abs;\n digits = typeof digits === \"number\" ? digits : 4;\n if (!isFinite(value)) return \"--\";\n abs = Math.abs(value);\n if (abs === 0) return \"0\";\n if (abs >= 1000) return value.toFixed(1);\n if (abs >= 100) return value.toFixed(2);\n if (abs >= 10) return value.toFixed(3);\n return value.toFixed(digits);\n }\n\n function parseValue(raw) {\n var cleaned;\n var n;\n if (raw === \"\" || raw === null || typeof raw === \"undefined\") return null;\n cleaned = String(raw).trim().replace(\/%$\/, \"\");\n if (cleaned === \"\") return null;\n n = Number(cleaned);\n return isFinite(n) ? n : null;\n }\n\n function isPercent() {\n return els.strainFormat.value === \"percent\";\n }\n\n function fromDecimalStrain(value) {\n if (!isFinite(value)) return \"\";\n return isPercent() ? value * 100 : value;\n }\n\n function currentStressUnit() {\n return els.stressUnit.value || (els.unitSystem.value === \"metric\" ? \"MPa\" : \"ksi\");\n }\n\n function stressToMPa(value) {\n return parseFloat(value) * unitFactors[currentStressUnit()];\n }\n\n function mpaToStress(value) {\n return value \/ unitFactors[currentStressUnit()];\n }\n\n function currentE() {\n return stressToMPa(els.youngsModulus.value);\n }\n\n function showResults() {\n els.resultsSection.className = \"ncalc-section ncalc-visible\";\n }\n\n function hideResults() {\n els.resultsSection.className = \"ncalc-section\";\n }\n\n function addMessage(type, text) {\n var div = document.createElement(\"div\");\n div.className = \"ncalc-message \" + type;\n div.appendChild(document.createTextNode(text));\n els.messageBox.appendChild(div);\n }\n\n function clearMessages() {\n els.messageBox.innerHTML = \"\";\n }\n\n function getFieldValue(tr, field) {\n var input = tr.querySelector('[data-field=\"' + field + '\"]');\n return input ? input.value : \"\";\n }\n\n function createRow(data) {\n var tr = document.createElement(\"tr\");\n var fields = [\n [\"engStrain\", data.engStrain || \"\"],\n [\"engStress\", data.engStress || \"\"],\n [\"trueStrain\", data.trueStrain || \"\"],\n [\"trueStress\", data.trueStress || \"\"],\n [\"truePlastic\", data.truePlastic || \"\"],\n [\"lnPlastic\", \"\"],\n [\"lnStress\", \"\"]\n ];\n var tdIndex = document.createElement(\"td\");\n tdIndex.className = \"ncalc-row-index\";\n tr.appendChild(tdIndex);\n fields.forEach(function (field) {\n var td = document.createElement(\"td\");\n var input = document.createElement(\"input\");\n input.setAttribute(\"data-field\", field[0]);\n input.type = field[0] === \"lnPlastic\" || field[0] === \"lnStress\" ? \"text\" : \"number\";\n input.step = \"any\";\n input.value = field[1];\n if (field[0] === \"lnPlastic\" || field[0] === \"lnStress\") input.readOnly = true;\n input.addEventListener(\"input\", hideResults);\n input.addEventListener(\"paste\", handleTablePaste);\n td.appendChild(input);\n tr.appendChild(td);\n });\n return tr;\n }\n\n function setRows(rows) {\n els.dataBody.innerHTML = \"\";\n rows.forEach(function (row) {\n els.dataBody.appendChild(createRow(row));\n });\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr, idx) {\n tr.querySelector(\".ncalc-row-index\").appendChild(document.createTextNode(String(idx + 1)));\n });\n }\n\n function populatePresetSelect() {\n var list = presets[els.unitSystem.value];\n els.materialPreset.innerHTML = \"\";\n list.forEach(function (item) {\n var opt = document.createElement(\"option\");\n opt.value = item.name;\n opt.appendChild(document.createTextNode(item.name));\n els.materialPreset.appendChild(opt);\n });\n }\n\n function updateUnitOptions() {\n els.stressUnit.innerHTML = \"\";\n stressUnitOptions[els.unitSystem.value].forEach(function (unit) {\n var opt = document.createElement(\"option\");\n opt.value = unit;\n opt.appendChild(document.createTextNode(unit));\n els.stressUnit.appendChild(opt);\n });\n els.stressUnit.value = els.unitSystem.value === \"metric\" ? \"MPa\" : \"ksi\";\n }\n\n function applyPreset() {\n var list = presets[els.unitSystem.value];\n var preset = null;\n list.forEach(function (item) {\n if (item.name === els.materialPreset.value) preset = item;\n });\n if (!preset) return;\n els.materialName.value = preset.name;\n els.youngsModulus.value = preset.e ? formatNumber(preset.e, 3).replace(\/\\.?0+$\/, \"\") : \"\";\n }\n\n function convertDisplayedStressFields(fromUnit, toUnit) {\n var factor;\n if (!fromUnit || !toUnit || fromUnit === toUnit) return;\n factor = unitFactors[fromUnit] \/ unitFactors[toUnit];\n [els.youngsModulus, els.inverseStress].forEach(function (field) {\n var val = parseFloat(field.value);\n if (isFinite(val)) field.value = formatNumber(val * factor, 4);\n });\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr) {\n [\"engStress\", \"trueStress\"].forEach(function (fieldName) {\n var input = tr.querySelector('[data-field=\"' + fieldName + '\"]');\n var val = input ? parseFloat(input.value) : NaN;\n if (both(input, isFinite(val))) input.value = formatNumber(val * factor, 4);\n });\n });\n }\n\n function convertDisplayedStrainFields(fromPercent, toPercent) {\n var factor;\n if (fromPercent === toPercent) return;\n factor = fromPercent ? 0.01 : 100;\n [els.neckingOnset, els.rangeMin, els.rangeMax, els.predictionStrain, els.comparisonStrain].forEach(function (field) {\n var val = parseFloat(field.value);\n if (isFinite(val)) field.value = formatNumber(val * factor, 5);\n });\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr) {\n [\"engStrain\", \"trueStrain\", \"truePlastic\"].forEach(function (fieldName) {\n var input = tr.querySelector('[data-field=\"' + fieldName + '\"]');\n var val = input ? parseFloat(input.value) : NaN;\n if (both(input, isFinite(val))) input.value = formatNumber(val * factor, 6);\n });\n });\n }\n\n function handleTablePaste(event) {\n var text = event.clipboardData ? event.clipboardData.getData(\"text\") : \"\";\n var startCell;\n var startRow;\n var rows;\n var tableRows;\n var rowIndex;\n var fieldOrder = [\"engStrain\", \"engStress\", \"trueStrain\", \"trueStress\", \"truePlastic\"];\n var startInput;\n var startIndex;\n if (!text || both(text.indexOf(\"\\n\") === -1, text.indexOf(\"\\t\") === -1)) return;\n event.preventDefault();\n startCell = event.target.closest(\"td\");\n startRow = event.target.closest(\"tr\");\n rows = text.trim().split(\/\\r?\\n\/).map(function (line) {\n return line.split(\/[\\t,;]+\/);\n });\n tableRows = Array.prototype.slice.call(els.dataBody.querySelectorAll(\"tr\"));\n rowIndex = tableRows.indexOf(startRow);\n startInput = startCell ? startCell.querySelector(\"input[data-field]\") : null;\n startIndex = fieldOrder.indexOf(startInput ? startInput.getAttribute(\"data-field\") : \"\");\n rows.forEach(function (values, r) {\n var targetRow = tableRows[rowIndex + r];\n if (!targetRow) return;\n values.forEach(function (value, c) {\n var field = fieldOrder[(startIndex >= 0 ? startIndex : 0) + c];\n var input = targetRow.querySelector('[data-field=\"' + field + '\"]');\n if (input) input.value = value.trim();\n });\n });\n hideResults();\n }\n\n function classifyFit(r2) {\n var good = parseFloat(els.goodThreshold.value) || 0.98;\n var moderate = parseFloat(els.moderateThreshold.value) || 0.95;\n if (!isFinite(r2)) return { label: \"Pending\", cls: \"\" };\n if (r2 >= good) return { label: \"Good\", cls: \"good\" };\n if (r2 >= moderate) return { label: \"Moderate\", cls: \"warn\" };\n return { label: \"Poor\", cls: \"warn\" };\n }\n\n function convertRow(row) {\n var strainType = els.strainType.value;\n var stressType = els.stressType.value;\n var eModulus = currentE();\n var engStrain = parseValue(row.engStrain);\n var engStress = parseValue(row.engStress);\n var trueStrain = parseValue(row.trueStrain);\n var trueStress = parseValue(row.trueStress);\n var truePlastic = parseValue(row.truePlastic);\n\n if (!isFinite(eModulus) || eModulus <= 0) return { valid: false, warnings: [\"Young's modulus must be greater than zero.\"] };\n\n if (strainType === \"engineeringStrain\") {\n if (engStrain === null) return { valid: false, warnings: [] };\n trueStrain = Math.log(1 + engStrain);\n } else if (strainType === \"trueTotal\") {\n if (both(trueStrain === null, engStrain !== null)) trueStrain = Math.log(1 + engStrain);\n } else if (strainType === \"truePlastic\") {\n if (truePlastic === null) return { valid: false, warnings: [] };\n }\n\n if (stressType === \"engineeringStress\") {\n if (engStress === null) return { valid: false, warnings: [] };\n if (strainType === \"engineeringStrain\") {\n trueStress = engStress * (1 + engStrain);\n } else if (both(strainType === \"trueTotal\", trueStrain !== null)) {\n engStrain = Math.exp(trueStrain) - 1;\n trueStress = engStress * (1 + engStrain);\n } else if (both(strainType === \"truePlastic\", engStrain !== null)) {\n trueStress = engStress * (1 + engStrain);\n } else {\n return { valid: false, warnings: [] };\n }\n } else if (trueStress === null) {\n return { valid: false, warnings: [] };\n }\n\n if (trueStress === null || !isFinite(trueStress) || trueStress <= 0) {\n return { valid: false, warnings: [\"True stress must be greater than zero.\"] };\n }\n\n if (strainType === \"truePlastic\") {\n if (!isFinite(truePlastic) || truePlastic <= 0) {\n return { valid: false, warnings: [\"True plastic strain must be greater than zero.\"] };\n }\n } else {\n if (!isFinite(trueStrain)) return { valid: false, warnings: [] };\n truePlastic = trueStrain - trueStress \/ eModulus;\n }\n\n if (!isFinite(truePlastic) || truePlastic <= 0) {\n return { valid: false, warnings: [\"Negative or zero plastic strain after conversion.\"] };\n }\n\n return {\n valid: true,\n engStrain: engStrain,\n engStress: engStress,\n trueStrain: trueStrain,\n trueStress: trueStress,\n truePlastic: truePlastic,\n lnPlastic: Math.log(truePlastic),\n lnStress: Math.log(trueStress),\n warnings: []\n };\n }\n\n function regress(points) {\n var n = points.length;\n var meanX = points.reduce(function (s, p) { return s + p.x; }, 0) \/ n;\n var meanY = points.reduce(function (s, p) { return s + p.y; }, 0) \/ n;\n var sxx = points.reduce(function (s, p) { return s + Math.pow(p.x - meanX, 2); }, 0);\n var sxy = points.reduce(function (s, p) { return s + (p.x - meanX) * (p.y - meanY); }, 0);\n var slope = sxy \/ sxx;\n var intercept = meanY - slope * meanX;\n var predictions = points.map(function (p) { return intercept + slope * p.x; });\n var ssRes = points.reduce(function (s, p, i) { return s + Math.pow(p.y - predictions[i], 2); }, 0);\n var ssTot = points.reduce(function (s, p) { return s + Math.pow(p.y - meanY, 2); }, 0);\n var r2 = ssTot === 0 ? 1 : 1 - ssRes \/ ssTot;\n return { slope: slope, intercept: intercept, r2: r2 };\n }\n\n function renderTablePreview(rows) {\n Array.prototype.forEach.call(els.dataBody.querySelectorAll(\"tr\"), function (tr, idx) {\n var row = rows[idx];\n var lnPlastic = tr.querySelector('[data-field=\"lnPlastic\"]');\n var lnStress = tr.querySelector('[data-field=\"lnStress\"]');\n if (both(row, row.valid)) {\n if (lnPlastic) lnPlastic.value = formatNumber(row.lnPlastic, 6);\n if (lnStress) lnStress.value = formatNumber(row.lnStress, 6);\n } else {\n if (lnPlastic) lnPlastic.value = \"\";\n if (lnStress) lnStress.value = \"\";\n }\n });\n }\n\n function calculate() {\n var rawRows;\n var conversionRows;\n var warnings = [];\n var validRows;\n var min;\n var max;\n var filtered;\n var points;\n var twoPointMode;\n var requiredPoints;\n var result = null;\n var n;\n var intercept;\n var kValue;\n var fit;\n var predStrain;\n var invStress;\n var predictedStress;\n var inverseStrain;\n\n showResults();\n clearMessages();\n\n rawRows = Array.prototype.map.call(els.dataBody.querySelectorAll(\"tr\"), function (tr) {\n return {\n engStrain: getFieldValue(tr, \"engStrain\"),\n engStress: getFieldValue(tr, \"engStress\"),\n trueStrain: getFieldValue(tr, \"trueStrain\"),\n trueStress: getFieldValue(tr, \"trueStress\"),\n truePlastic: getFieldValue(tr, \"truePlastic\")\n };\n });\n\n conversionRows = rawRows.map(convertRow);\n conversionRows.forEach(function (row) {\n row.warnings.forEach(function (warning) {\n warnings.push(warning);\n });\n });\n renderTablePreview(conversionRows);\n\n validRows = conversionRows.filter(function (row) {\n return row.valid;\n });\n min = parseValue(els.rangeMin.value);\n max = parseValue(els.rangeMax.value);\n if (both(both(min !== null, max !== null), min > max)) {\n var temp = min;\n min = max;\n max = temp;\n }\n\n filtered = validRows.filter(function (row) {\n if (both(min !== null, row.truePlastic < min)) return false;\n if (both(max !== null, row.truePlastic > max)) return false;\n return true;\n });\n\n points = filtered.map(function (row) {\n return { x: Math.log(row.truePlastic), y: Math.log(row.trueStress), row: row };\n });\n twoPointMode = els.mode.value === \"twoPoint\";\n requiredPoints = twoPointMode ? 2 : 3;\n if (points.length < requiredPoints) {\n warnings.push(twoPointMode ? \"Two-point calculation requires at least two valid points.\" : \"Regression requires at least three valid points.\");\n }\n\n if (both(twoPointMode, points.length >= 2)) {\n result = regress(points);\n n = Math.log(filtered[1].trueStress \/ filtered[0].trueStress) \/ Math.log(filtered[1].truePlastic \/ filtered[0].truePlastic);\n intercept = Math.log(filtered[0].trueStress) - n * Math.log(filtered[0].truePlastic);\n result = { slope: n, intercept: intercept, r2: result.r2 };\n } else if (both(!twoPointMode, points.length >= 3)) {\n result = regress(points);\n }\n\n if (result) {\n n = result.slope;\n kValue = Math.exp(result.intercept);\n fit = classifyFit(result.r2);\n predStrain = parseValue(els.predictionStrain.value);\n invStress = parseValue(els.inverseStress.value);\n predictedStress = both(predStrain, predStrain > 0) ? kValue * Math.pow(predStrain, n) : null;\n inverseStrain = both(both(invStress, invStress > 0), n !== 0) ? Math.pow(invStress \/ kValue, 1 \/ n) : null;\n\n els.outN.textContent = formatNumber(n, 5);\n els.outK.textContent = formatNumber(mpaToStress(kValue), 4);\n els.outR2.textContent = formatNumber(result.r2, 4);\n els.outIntercept.textContent = formatNumber(result.intercept, 5);\n els.outCount.textContent = String(filtered.length);\n els.outRange.textContent = \"Used \" + (min !== null ? fromDecimalStrain(min) : \"auto\") + \" to \" + (max !== null ? fromDecimalStrain(max) : \"auto\") + \" (\" + els.strainFormat.value + \")\";\n els.outFit.textContent = \"Fit quality: \" + fit.label;\n els.outKUnit.textContent = currentStressUnit();\n els.outPredStress.textContent = predictedStress !== null ? formatNumber(mpaToStress(predictedStress), 4) + \" \" + currentStressUnit() : \"--\";\n els.outInvStrain.textContent = inverseStrain !== null ? formatNumber(inverseStrain, 5) : \"--\";\n els.outUniform.textContent = formatNumber(n, 5) + \" \/ \" + formatNumber(Math.exp(n) - 1, 5);\n } else {\n els.outN.textContent = \"--\";\n els.outK.textContent = \"--\";\n els.outR2.textContent = \"--\";\n els.outIntercept.textContent = \"--\";\n els.outCount.textContent = \"--\";\n els.outRange.textContent = \"Selected strain range pending\";\n els.outFit.textContent = \"Fit quality pending\";\n els.outKUnit.textContent = currentStressUnit();\n els.outPredStress.textContent = \"--\";\n els.outInvStrain.textContent = \"--\";\n els.outUniform.textContent = \"--\";\n }\n\n warnings.filter(function (value, index, array) {\n return array.indexOf(value) === index;\n }).forEach(function (warning) {\n addMessage(\"warn\", warning);\n });\n if (both(!warnings.length, result)) addMessage(\"good\", \"Computed n = \" + formatNumber(n, 5) + \" with \" + filtered.length + \" valid points.\");\n }\n\n function wireEvents() {\n var controls = [\n els.mode, els.unitSystem, els.stressUnit, els.strainFormat, els.materialPreset, els.materialName,\n els.youngsModulus, els.stressType, els.strainType, els.neckingOnset, els.rangeMin, els.rangeMax,\n els.predictionStrain, els.comparisonStrain, els.inverseStress, els.goodThreshold, els.moderateThreshold\n ];\n controls.forEach(function (el) {\n el.addEventListener(\"input\", function () {\n var oldUnit;\n var newUnit;\n var fromPercent;\n var toPercent;\n hideResults();\n if (el === els.unitSystem) {\n oldUnit = state.lastStressUnit || currentStressUnit();\n updateUnitOptions();\n populatePresetSelect();\n applyPreset();\n newUnit = currentStressUnit();\n if (oldUnit !== newUnit) convertDisplayedStressFields(oldUnit, newUnit);\n state.lastStressUnit = newUnit;\n }\n if (el === els.stressUnit) {\n oldUnit = state.lastStressUnit || currentStressUnit();\n newUnit = currentStressUnit();\n if (oldUnit !== newUnit) convertDisplayedStressFields(oldUnit, newUnit);\n state.lastStressUnit = newUnit;\n }\n if (el === els.strainFormat) {\n fromPercent = state.lastStrainPercent || false;\n toPercent = isPercent();\n if (fromPercent !== toPercent) convertDisplayedStrainFields(fromPercent, toPercent);\n state.lastStrainPercent = toPercent;\n }\n if (el === els.materialPreset) applyPreset();\n });\n });\n els.calcBtn.addEventListener(\"click\", calculate);\n }\n\n function init() {\n updateUnitOptions();\n populatePresetSelect();\n setRows(defaultRows);\n els.materialPreset.value = \"Low Carbon Steel\";\n applyPreset();\n els.materialName.value = \"Low Carbon Steel\";\n els.stressType.value = \"trueStress\";\n els.strainType.value = \"truePlastic\";\n els.youngsModulus.value = 200000;\n state.lastStressUnit = currentStressUnit();\n state.lastStrainPercent = isPercent();\n wireEvents();\n hideResults();\n }\n\n init();\n }());\n <\/script>\n<\/body>\n<\/html>\n","protected":false},"excerpt":{"rendered":"<p>The Strain Hardening Exponent n Calculator is a practical engineering tool designed to calculate the strain hardening exponent (n-value) from tensile test data using 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