具确定弱区域正交各向异性薄板的弹塑性屈曲分析

基于弹塑性力学和损伤理论,建立了一个与应力球张量有关的具损伤正交各向异性材料的混合硬化屈服准则,该准则无量纲化后与各向同性材料的Mises准则同构,在此基础上,建立了正交各向异性材料的增量型和全量型弹塑性损伤本构方程,并以具确定弱区域正交各向异性矩形薄板为例,根据屈曲时的能量准则和全量理论,以等效塑性应变为内变量,对其弹塑性屈曲问题进行了分析,讨论了几何参数和弱区域对正交各向异性薄板弹塑性屈曲临界应力的影响.

ELASTO-PLASTIC BUCKLING ANALYSIS OF ORTHOTROPIC THIN PLATES WITH CERTAIN WEAK REGION

Based on elasto-plastic mechanics and damage theory, a yield criterion related to the spherical tensor of stress is proposed to describe the mixed hardening of damaged orthotropic materials,whose dimensionless form is isomorphic with Mises criterion of isotropic materials.Furthermore,the incremental and total elasto-plastic damage constitutive equations are established.As an example of applications,the elasto-plastic buckling of an orthotropic thin plate with a certain weak region under proportion loading is investigated using the energy criterion and the total theory of bucking.Taking the equivalent plastic strain as the internal variable,the effects of geometric parameters and the weak region on the critical buckling stress are discussed in detail.