Crystal Lattice Stress-Strain Simulator

A 2D grid of atoms is held together by real spring bonds — nearest-neighbor and diagonal — and stretched or compressed by displacing its right edge while the left edge stays fixed, exactly like a tensile-test machine gripping a coupon. Every frame, a mass-spring physics solver relaxes the whole lattice toward mechanical equilibrium, so the visible stretching, plastic slip and eventual fracture all emerge from the bonds themselves rather than a pre-scripted animation. A live stress-strain plot traces the sample's actual path through the elastic, plastic and fracture regions as you pull it, and switching material presets changes the underlying stiffness, yield strain and fracture strain to show how a ductile metal, a brittle ceramic and a polymer each fail differently.