Kagome平面格栅结构的屈服面及裂尖塑性区分析

ANALYSIS OF YIELD SURFACE AND CRACK TIP PLASTIC ZONE OF KAGOME LATTICE STRUCTURE

分析了Kagome格栅的等效刚度和屈服面.其屈服面奇异,由4段直线围成.利用该屈服面,估算了Kagome具有Ⅰ型、Ⅱ型半无限大裂纹的裂尖塑性区,有限元计算验证了解析预测的准确性.与奇异屈服面相比,由Mises光滑屈服面给出的塑性区误差较大.因此只有弹性情况,可以将Kagome等效为各向同性;若材料塑性,或应力场奇异性较强,Kagome的强度依赖于主应力方向,不能用各向同性模型来描述.

Effective stiffness and yield surface of Kagome lattice structure are investigated in the paper.The shape function of singular yield surface is a convex domain in the plane enclosed within four straight lines.The plastic zone of crack tips of modeⅠand modeⅡcracks in the infinite half plane are estimated with the singular yield surface and validated with finite element simulation,which are more precise than those with Mises smooth yield surface.Thus Kagome could be simplified as isotropic continuum only in e...