残余应力作用下弧齿锥齿轮裂纹扩展仿真分析

Crack Propagation Simulation Analysis of Spiral Bevel Gear Under Residual Stress

为探究淬火残余应力对弧齿锥齿轮裂纹扩展的影响,建立弧齿锥齿轮三维数值模型。首先,基于扩展有限元法(XFEM)模拟不同工况下齿根裂纹扩展路径;其次,采用热力耦合法得到淬火残余应力,将其作为初始条件求解应力强度因子。分析残余应力作用下应力强度因子随不同载荷、不同裂纹长度的演化规律,揭示残余应力对裂纹扩展的影响机理。结果表明,残余拉应力对轮齿基体裂纹扩展起促进作用;弧齿锥齿轮在靠近轮齿大端的裂纹扩展速率大于小端的扩展速率。

In order to explore the influence of quenching residual stress on crack propagation of spiral bevel gear,a three-dimensional crack numerical model of spiral bevel gear was established.Firstly,the propagation path of tooth root crack under different working conditions is simulated based on XFEM.Secondly,the quenching residual stress is obtained by thermal-mechanical coupling method as the initial condition to solve the stress intensity factor.Finally,the evolution law of stress intensity factor with different loads and different crack lengths under residual stress is analyzed to reveal the influence mechanism of residual stress on crack propagation.The results show that residual tensile stress promotes the crack propagation of gear matrix;the crack propagation rate of spiral bevel gear near the large end of gear tooth is greater than that of the small end.