榫连结构的高应力梯度及破坏分析

某燕尾形榫连结构的分析表明叶盘榫齿/榫槽接触区边缘存在较高的应力梯度,接触应力的有限元解同网格疏密程度密切相关.通过建立一系列不同密度网格的模型,对此问题展开有限元建模分析,以改善接触应力的求解精度,同时深入讨论材料弹塑性对接触应力的影响.在弹塑性接触应力分析的基础上,采用断裂力学方法建立了榫连结构高应力梯度位置的破坏分析模型,判断裂纹的萌生及扩展方向,以进行结构的强度及寿命分析.

On the high stress gradient and failure analysis of dovetail attachments

Studies reveals that high stress gradient exists near the edges of contact in dovetail attachment, of which the numerical solution to contact stress depends on finite element (FE) mesh density. So a set of FE models with different mesh of dovetail attachment were used to analyze the effect of FE modeling on improving the solving accuracy of contact stress. Then the effect due to elasticity and plasticity of materials was discussed. On the basis of elastic-plastic contact stress, a fracture model on the part with high stress gradient was established by means of fracture mechanics, which can be used to determine the direction of crack initiation and propagation and more to evaluate the structural strength and lives.