基于双剪统一强度理论的圆板塑性极限分析

通过对轴对称弯曲圆板在塑性极限状态下应力和弯曲内力的分布研究,建立了双剪统一强度理论下用弯矩表示的屈服条件,即广义双剪统一屈服条件。该广义双剪统一屈服条件是一条对称的外凸闭合折线,可应用于由各种拉压强度比及剪压强度比材料构成的圆板和环板的塑性极限分析。对均布荷载作用下的简(固)支圆板进行了塑性极限分析,得出了圆板的塑性极限荷载、塑性极限状态时的内力场和速度场,分析了拉压强度比α以及中间剪应力影响系数b对塑性极限承载力的影响。

PLASTIC LIMIT ANALYSIS OF CIRCULAR PLATES BASED ON TWIN SHEAR UNIFIED STRENGTH THEORY

Based on the analysis of stress and bending moment distribution of rotationally symmetrical circular plates in plastic limit state, a generalized twin shear unified yield condition in terms of bending moments is developed in the context of twin-shear unified strength theory. The generalized twin shear unified yield condition is a symmetric folded line, convex outward and closed. It can be applied to the plastic limit analysis of circular and annular plates, and the materials can have any tensile to compression strength ratio and any shear to compression strength ratio. The plastic limit states of simply supported and clamped circular plates are analyzed. Their ultimate loads, moment fields and velocity fields in plastic limit states are obtained. The ultimate loads varied with the tensile to compress strength ratio α and the media shear stress factor b. Their influences are analyzed.