索杆结构中索滑移行为分析的有限质点法

THE FINITE PARTICLE METHOD FOR ANALYSING CABLE SLIDING IN CABLE-STRUT STRUCTURES

索杆结构成形过程中,连续索在一些节点处能够相对滑移,索与节点间的连接不能按铰接简单处理,传统有限元对此类问题的求解多有不便。针对索在节点处的滑移问题,该文采用一种新型分析方法—有限质点法,将连续索离散成相互联系的质点集合,质点运动满足牛顿第二定律,索的滑移行为通过质点的运动来描述。该文推导了滑移索单元内力求解公式,提出了滑移索单元的判定方法,通过自编程序对算例进行计算分析,验证了滑移索单元的正确性和合理性。

In some cable-strut structures, the special type of joins are designed to allow the cables to slide through freely. The cable cannot be simplified as a 2-node straight bar with the end fixed by the joins, and a special modification is needed in a traditional finite element method. A new developed algorithm called the finite particle method(FPM) is applied to the cable slide analysis. It models a continuous cable by a set of finite particles, and the motion of each particle follows Newton's second law. The cable slide behavior is described by the motion of particles. The formulations to calculate the internal forces of the sliding cable element are derived. The criterion for the determination of a relationship between joins and sliding cable elements is also proposed. The results of numerical examples calculated by self-designed program verify the rationality of the sliding cable element used for cable slide situations.