十字轴表面裂纹仿真与材料的断裂韧性试验

Simulation of Surface Crack of Cruciform Axis and Experiment of Fracture Toughness of Material

针对万向联轴器十字轴结构安全性问题,从表面缺陷裂纹应力强度因子角度分析十字轴断裂情况。建立十字轴三维模型,运用ANSYS WorkBench对十字轴进行静力学分析,找出十字轴轴径圆弧处应力最大。然后在分析后的模型中插入半椭圆形裂纹,进行表面裂纹分析。最后,在低周疲劳试验机上进行三点弯曲试验与柔度法得到十字轴材料的平面断裂韧性。研究结果表明:在十字轴轴径处裂纹大小长半轴半径c=5mm,短半轴半径a=1mm的半椭圆形裂纹得到十字轴应力强度因子大于材料试验的KIC,十字轴出现裂纹断裂。

Aiming at the safety problem of the cross shaft structure of the universal coupling,the fracture situation of the cross shaft is analyzed from the perspective of the stress intensity factor of surface flaw.Establish a dimensional model of the cross shaft,and use ANSYS WorkBench to carry out static analysis on the cross shaft to find the maximum stress at the arc of the cross shaft diameter.Then insert the analyzed model into the semiellipse crack to conduct surface crack analysis.Finally,a three-point bending test was conducted on a low cycle fatigue testing machine to obtain the plane fracture toughness of the cross shaft material.The results show that:at the cross shaft axis diameter,the size of the crack is semiellipse with a long semi-axis radius of c=5mm and a short semi-axis radius of a=lmm.The stress intensity factor of the cross axis is greater than that of the material test Kic.