SpannungVerformungsBeziehung

Spannungsverformung, or the stress–strain behavior, is a fundamental concept in materials science and engineering that describes how a material deforms under applied mechanical loads. It relates internal stresses to the resulting deformations, typically shown as a stress–strain curve produced in a tensile or compressive test. Stress is the internal force per unit area, while strain is the relative change in dimension.

In the elastic region, deformation is reversible: removing the load restores the original shape. The relationship is commonly approximated by Hooke’s law, with stiffness quantified by Young’s modulus. Beyond the elastic limit, plastic deformation begins, and permanent shape changes remain after unloading. The yield strength marks the onset of plasticity; further loading leads to work hardening, possible necking in tension, and eventual fracture at the ultimate tensile strength or failure point. Different materials exhibit distinct behaviors: metals often show clear elastic-plastic transitions, while polymers and composites may display viscoelastic or nonlinear responses.

Several factors influence Spannungsverformung, including temperature, strain rate, and microstructure. Time-dependent or rate-sensitive materials exhibit viscoelastic or viscoplastic behavior, where deformation depends on how quickly the load is applied. In engineering analysis, stress–strain data inform material selection, design allowable stresses, and safety factors. Theoretical descriptions use models such as linear elasticity for the initial region and plasticity theories with yield criteria (e.g., Von Mises, Tresca) for plastic flow.

Measurement typically relies on standardized tensile tests to generate curves that capture stiffness, yield, hardening, and failure. Limitations include dependence on loading conditions, texture, anisotropy, and environmental factors.