形状记忆合金受弯杆横截面上的应力分布

Stress Distribution on Cross-Section of Bending Bar of Shape Memory Alloys

从Brinson本构理论出发 ,将材料沿构件的纵向等效成若干纤维丝的组合 ,并假定在受力时由这些纤维丝组合而成的横断面上的应变大小沿着截面高度呈线性变化 ,即同一横断面的变形符合平截面假定 ,从而建立起形状记忆合金在弯矩作用下截面上的应力沿截面高度的关系式 通过实例分析 ,认为构件在弯矩作用下横断面上的应力沿截面高度呈非线性分布 ,并有明显的相变点 ;同时发现在相同的应变情况下 ,加载时的应力明显大于卸载时应力 ,出现应力滞后 。

Based on Brinson constitutive relation,the material of a bending bar is replaced with some combination fascicules in the longitudinal axis, and assumed that the strain changes with linear relation along height of cross section combined with these fascicules when the bar is bended, i.e. the deformation of cross section is in accordance with the plane cross section assumption,constituting change relation of stress along height of cross section when shape memory alloys bar is bended. By example analyzing,thinking stress distribution is nonlinear along height of cross section when shape memory alloys bar is bended.It shows also that the stress when loaded is large than unloading at same strain,i.e. the on behavior of stress delay occurs;therefore, shape memory alloys can be used for energy dissipation material when shape memory alloys bar is bended.