基于循环J积分的压力容器疲劳寿命预测的数值模拟

开发出一种基于三维弹塑性循环J积分( J)的压力容器疲劳寿命预测的数值模拟技术。对1台含内壁纵向表面裂纹的实物压力容器进行有限元数值模拟计算和试验测试，结果显示：初始椭圆形表面裂纹在疲劳扩展过程中形状逐渐趋圆并保持圆形继续扩展。裂纹疲劳扩展过程是一个非等速的扩展过程，扩展速度呈现越来越快的趋势。基于J的疲劳寿命预测的数值模拟结果较之基于应力强度因子幅K的结果具有更高的精度，满足工程要求。该技术对于在役含缺陷压力容器的疲劳寿命预测具有重要的应用价值。

NUMERICAL SIMULATION OF FATIGUE LIFE PREDICTION OF PRESSURE VESSEL BASED ON CYCLIC J-INTEGRAL

A numerical simulation technology of fatigue life prediction of pressure vessel based on cyclic J-integral is developed. Through finite element numerical calculation and experiment test on pressure vessel containing inner portrait surface crack, the results show that initia ellipse surface crack tends to round surface crack gradually during fatigue developing and keeps the round shape to develop. The velocity of crack fatigue development is not uniform and presents the trend of more quickly. The numerical simulation results of fatigue life prediction based on J have higher precision than those of K based and satisfy the engineering requirement. This technology have important application value for fatigue life prediction of pressure vessel in use containing defects.