Deformacj

Deformacj is the change in an object's shape, size, or internal structure resulting from external actions such as mechanical loads, temperature changes, or phase transitions. In solids, deformation is commonly described by strain, the relative change in length, and stress, the internal force per area. For small deformations, linear elastic behavior is modeled by Hooke's law, where stress is proportional to strain (σ = Eε). If the yield threshold is exceeded, permanent deformation occurs, known as plastic deformation, enabled by dislocation motion and, in crystals, mechanisms like slip and twinning. Viscoelastic materials exhibit time-dependent deformation, combining elastic recovery with viscous flow.

Deformations can be classified by reversibility (elastic vs plastic), by rate (instantaneous vs time-dependent), or by geometry (small-strain vs finite deformation). Thermal expansion is a common non-mechanical deformation caused by temperature change, described by coefficients of thermal expansion.

Deformation is central to many fields: in engineering, components are designed to tolerate expected deformations; in manufacturing, metal forming relies on plastic deformation; in geology, tectonic stresses deform rocks to create folds and faults; in biomechanics, tissues deform under loads. Measurement approaches include strain gauges, extensometers, and digital image correlation. Understanding deformation requires considering material structure, temperature, loading path, and time. Properly predicting and controlling deformation ensures safety, functionality, and performance of structures and devices.