微动工况对疲劳裂纹扩展影响的数值模拟研究

文章研究了不同微动工况对疲劳裂纹扩展的影响,在Hypermesh中建立带有预置裂纹的有限元模型,把单元和节点信息导入Matlab,利用向量式有限元法研究薄板在恒定拉载荷、恒定压载荷、拉压载荷和交变载荷作用时的裂纹扩展规律。研究表明,恒定拉载荷和交变载荷作用下,裂纹开口形状和程度大致相同;裂纹在恒定压载荷作用下发生交错;在拉载荷作用时裂纹开口幅度达到最大值,拉压载荷作用下裂纹扩展开口幅度最小,其次,在交变载荷下裂纹扩展速度最快,拉载荷和压载荷作用下裂纹扩展最慢。

Numerical Simulation of the Effect of Fretting Conditions on Fatigue Crack Propagation

This paper studied the crack propagation of fretting fatigue under different fretting conditions. A finite element model with a pre-set crack was developed in Hypermesh, a commercial software. Then the element and node information of the model was exported to Matlab. The propagation rule of the fatigue crack was numerically studied using vector form intrinsic finite element method under different fretting conditions. The results show that the expansion shape of the crack is almost the same for a constant tensile load and a fluctuating load. The crack interlace with each other at a constant compressive load. Compare to other loads, the crack width reaches the maximum when a constant tensile load was applied while the crack width is the minimum when the tensile and compressive load was used. In addition, the crack expansion rate is the fastest at the fluctuating load. The expansion rate is slower when the constant tensile load or the constant compressive load was applied.