Mechanical Behaviour

How materials carry load. Stress, strain and elasticity, tensile and hardness testing, and strengthening mechanisms.

• Stress — Stress is internal force per unit area. Learn normal (tensile/compressive) stress, bearing stress, allowable stress and factor of safety, stress concentrations, and thin-walled pressure vessels.
• Strain — Strain is deformation per unit length. Learn normal and shear strain, microstrain, the stress–strain curve, ductility, lateral strain and Poisson's ratio, and how strain gauges measure it.
• Elasticity — Elasticity is a material's ability to spring back. Learn Hooke's law, Young's, shear and bulk moduli, axial deformation δ = PL/AE, stiffness, thermal stress and composite bars.
• Mechanical Properties & Materials Testing — How materials respond to loads — and how we measure it. Learn the tensile test (engineering vs true stress–strain, elastic modulus, 0.2% offset yield, UTS, necking, elongation and reduction of area, resilience, toughness), strain hardening (Hollomon equation), hardness tests (Brinell, Vickers, Rockwell) and their link to strength, impact testing (Charpy) and the ductile-to-brittle transition, strengthening mechanisms (grain size/Hall–Petch, solid solution, work hardening, precipitation), variability and safety factors — with Python extracting properties from tensile data and computing Hall–Petch strengthening.