应变强化模型的安定准则研究

STUDY ON THE SHAKEDOWN OF STRAIN-HARDENING STRUCTURES

基于Melan经典的安定理论和von Mises屈服准则,建立了塑性应变强化条件下结构安定的数学模型,根据与时间无关的应力场的特性,对结构中与时间无关的应力场进行了合理的数学变换,将其与载荷变化系数联系起来,推导出与其对应的结构安定极限范围的表达式,给出塑性应变强化模型安定性存在的简化条件.该结论有利于简化应变强化条件下结构的安定分析.

An analytical method of structures shakedown under plastic strain-hardening conditions has been developed based on Melan＇s theorem and Von Mises yield criterion. Relation between time-independent stresses field and elastic stresses subjected to external loadings is established based on mathematical approach, then the shakedown expressions of structures are given. Thus, the simple shakedown theorem of structure under external loading is presented according to the time-independent stresses and proved by Melan＇s theorem. The theorem is convenient to evaluate shakedown limit of structures without tedious computations compared with the traditional method. The theorem is propitious to simplify the shakedown analysis of strain-hardening structures by the mathematical example.