Stress & Strain Calculator
Stress and strain are fundamental concepts in materials science and mechanical engineering. Stress (sigma = F/A) measures the internal force per unit area in a material, while strain (epsilon = delta-L/L) measures the relative deformation. Their ratio yields Young's modulus, which characterizes material stiffness.
Stress (σ = F/A) is measured in pascals (Pa) or megapascals (MPa). It represents the intensity of internal forces within a material. Since 1 N/mm² = 1 MPa, entering force in newtons and area in mm² directly gives stress in MPa. Structural steel typically yields at ~250 MPa and has an ultimate tensile strength of ~400-550 MPa.
Strain (ε = ΔL/L₀) is a dimensionless ratio measuring how much a material deforms relative to its original length. Elastic strain in metals is typically very small (0.001 to 0.005), while rubber can stretch to strains exceeding 1.0 (100% elongation).
Young's modulus (E = σ/ε) quantifies a material's stiffness, or its resistance to elastic deformation. Steel has E ≈ 200 GPa, aluminum ≈ 70 GPa, wood ≈ 10 GPa, and rubber ≈ 0.01 GPa. Young's modulus applies only in the elastic (linear) region of the stress-strain curve; beyond the yield point, permanent plastic deformation occurs.