Stress-Strain Universal Testing Machine Lab

GARR Foundation — Dr. APJ Abdul Kalam ZERO RESEARCH FUNDING Lab

ENGINEERING STREAMS: Mechanical, Civil, Aerospace, Materials Science, Structural, Metallurgy

PHYSICAL HARDWARE EQUIVALENT

Universal Testing Machine (UTM) & Extensometer

Servo-hydraulic tensile test frame with precision load cell.

IIT / IISC PHYSICAL SETUP COST

₹800,000 to ₹2,500,000 (₹8L - ₹25L)

Requires destructive specimens, safety shielding & high upkeep.

INDIAN INSTITUTES PHYSICAL DEPLOYMENT

IIT Madras, IIT Kanpur, IIT Kharagpur, IISc Bengaluru

Materials Testing & Strength of Materials Research Labs.

KALAM LAB ONLINE REPLACEMENT COST

₹0 (100% Free Open-Source)

Runs directly in browser on any smartphone, tablet, or budget PC.

UTM Control Panel

Select Material Specimen

Gauge Length ($L_0$) 50 mm

Specimen Diameter ($d$) 10.0 mm

Pull Rate / Crosshead Speed 0.05 mm/s

Real-Time Test Metrics

Applied Force ($F$)

0.00 kN

Stress ($\sigma$)

0.0 MPa

Strain ($\epsilon$)

0.0000

Young's Modulus ($E$)

0 GPa

Real-Time Specimen Deformation

Engineering Stress ($\sigma$) vs Strain ($\epsilon$) Curve

Live Curve

Yield Point

UTS Point

Fracture Point

How to Use, Understanding & Help

This virtual lab models tensile testing on a Universal Testing Machine (UTM). It calculates stress ($\sigma = \frac{F}{A_0}$) and strain ($\epsilon = \frac{\Delta L}{L_0}$) in real-time based on the mechanical properties of the selected material.

Core Controls Overview:

Select Material Specimen: Choose between ductile steel, aluminum, or brittle cast iron to observe differing failure modes.
Gauge Length ($L_0$) & Diameter ($d$): Set initial specimen dimensions which define cross-sectional area $A_0 = \frac{\pi d^2}{4}$.
Crosshead Speed: Controls the strain rate applied to the virtual specimen.
Start / Reset: Initiates automated tensile pulling until fracture or resets the load cell.

Step-by-Step Tuning / Testing Guide

Zero the Load Cell & Extensometer: Before applying load, select your material and specimen geometry. Verify stress and strain metrics start at zero.
Apply Elastic Loading: Click Start Tensile Test. Observe the initial linear region; the slope gives Young's Modulus ($E = \frac{\sigma}{\epsilon}$).
Identify Yield Point: Watch for the onset of non-linear behavior where permanent plastic deformation begins (Yield Strength).
Track Plastic Deformation & UTS: Observe strain hardening up to the maximum load, representing the Ultimate Tensile Strength (UTS).
Observe Necking & Fracture: Watch the physical specimen neck down in width until structural rupture occurs at the fracture stress level.

Why This Interactive Lab is Valuable for Engineering Students

Safe Failure Observation: Replicates destructive physical testing without material waste or hazardous high-tonnage equipment risks.
Real-Time Data Capture: Automatically plots the $\sigma$-$\epsilon$ curve live, mapping elastic limits, strain hardening, and necking.
Cost Efficiency: Eliminates the need for expensive physical Universal Testing Machines (UTM) and precision extensometers.

Target Engineering Streams

This lab provides practical experience for students across several engineering departments:

Mechanical Engineering

Essential for understanding material selection, yield criteria, machine design, and structural safety factors.

Civil & Structural Engineering

Crucial for evaluating steel/concrete rebar properties, allowable stresses, and structural integrity under load.

Aerospace Engineering

Vital for analyzing high-strength-to-weight alloys, fatigue limits, and structural failure modes under tension.

Materials Science & Metallurgy

Key for studying stress-strain relationships, strain hardening exponents, and ductile-to-brittle transitions.