基于Verity方法的焊缝疲劳评估原理及验证

Verity方法是计算焊缝疲劳寿命的最新方法.该方法是在有限元计算过程中,将焊趾处结点载荷向单元边分布载荷进行等效转换,以薄膜应力解析公式求解焊趾处结构应力,实现了结构应力对有限元网格不敏感方法.Verity方法还基于Paris断裂力学公式,推导了以等效结构应力幅为参数的主S-N曲线方程.为验证Verity方法的有效性,以装甲钢T形焊接接头为对象,进行了仿真计算与疲劳试验.结果表明,采用Verity方法计算结构应力具有网格不敏感特性,根据主S-N曲线方程计算结果与试验值较为接近,和其它传统焊缝疲劳评估方法相比,Verity方法计算精度高,优势明显.

Weld fatigue assessment and verification based on Verity method

Verity method is the latest method to calculate weld fatigue life.In the process of the finite element calculation,node load of weld toe is accordingly converted to the element edge distributive load,thin-shell stress analysis formula is used to solve the structure stress problem of weld toe,and the method that structure stress is insensitive to finite element mesh is reached.Based on the fracture mechanics formula of Paris,it took the equivalent structure stress amplitude as the main parameters of master S-N curve,and the curve equation is deduced.To verify the validity of Verity method,fatigue test and simulation of armored steel T-welded joints is conducted,the results show that Verity method calculating structure stress with the insensitivity characteristics of the element.Computing results according to master S-N curve equation is closer to experimental value.Compared with other traditional weld fatigue assessment methods,Verity method is of high accuracy and obvious advantage.