蠕变常被视为材料破坏的一种模式，通常将其定义为固体材料在受应力影响时的永久变形趋势。蠕变通常是长时间暴露在低于材料屈服强度的高水平应力下的结果。
Creep rate is a function of the material properties, exposure time, exposure temperature and the applied load. Depending on the magnitude of load and duration, the deformation may become so large that a component can no longer perform its function — for example, creep behavior in a turbine blade will cause the blade to contact the casing, resulting in the failure of the blade.
Creep properties are of concern to engineers and metallurgists when evaluating components that operate under high stresses and temperatures. Creep is a deformation mechanism that may even initiate a failure mode. In certain cases, such as creep in concrete, it can relieve tensile stresses that might otherwise lead to cracking. In biological materials, creep is often characterized to understand how certain tissues respond to biomechanical loading in both normal and sports-related activities.
Creep response can also occur in polymers and metals which are considered viscoelastic materials. When a polymeric material is subjected to an abrupt force, the response can be modeled using the Kelvin-Voigt model. In this model, the material is represented by a Hookean spring and a Newtonian dashpot in parallel.参见应力松弛 页面查看深入讨论。
TA ElectroForce ElectroForce test instruments are used to study a variety of creep behaviors and response for engineered materials and a variety of biological specimens. Contact us to discuss your particular application.
