多板交汇复杂板壳结构应力分布仿真和裂纹扩展原因分析

STRESS DISTRIBUTION SIMULATION FOR SECTION WITH MULTIPLE PLANES AND INVESTIGATION ON CRACK PROPAGATION IN THE SECTION

该文以国内某煤码头堆取料机的后L梁为研究对象,利用Solidworks、ANSYS和Hypermesh联合仿真研究了网格类型和密度对结构应力计算结果的影响,分析了L梁多板交汇处复杂板壳结构的应力分布,根据分析结果推测了裂纹萌生和扩展原因。研究结果表明:1)结构变更后的最大应力值比变更前略有减小,说明结构变更不是裂纹萌生的直接原因,是结构初始设计上的问题;2)改造后在臂架铰点处产生的不平衡力矩是造成裂纹萌生和扩展的直接原因;3)所提出的修复方案明显地降低了原裂纹处的应力,提高了疲劳强度。

Took the back ＂L＂ beam of a stacker-reclaimer as an example, whose section is composed of multiple planes. The stress distribution in the section of beam was simulated using Solidworks, ANSYS and Hypermesh, and the effects of mesh type and mesh size on the simulation results were investigated. The reason for crack initiation at the section was discussed based on the simulation results. The conclusions are as the following： 1） the original design of the structure is the main cause of the crack, while the reforming is not since the maximum stress decreases after reforming; 2） The unbalanced moment at the pin connection of the beam after reforming is the direct cause of the crack initiation and propagation; 3） The repairing plan is proved to reduce the stress at the crack initiation location and enhance the structure fatigue strength.