摘要
采用3.8 mm厚带有圆形缺口的CT试样,研究了16MnR钢在不同应力比的恒幅循环载荷作用下的疲劳裂纹扩展。开发了一种基于疲劳损伤的方法来模拟疲劳裂纹扩展速率。将16MnR钢的循环塑性本构模型通过用户材料子程序UMAT嵌入到ABAQUS中。把有限元计算得到的疲劳裂纹尖端附近区域的弹塑性循环应力应变结果,代入到疲劳损伤模型中,得到每个加载循环在裂尖各点产生的疲劳损伤值。通过疲劳损伤准则,导出疲劳裂纹稳定扩展速率的计算公式。疲劳裂纹扩展试验验证了模拟结果。实验结果和模拟结果都表明,该试样厚度下,应力比对裂纹扩展速率几乎没有影响。
Fatigue crack growth behavior of 16MnR steel was experimentally studied using compact specimens subjected to different R - atio cyclic loading. The fatigue crack growth rate for 16MnR steel was simulated based on damage method. The elastic- plastic stress- strain field near the crack tip under cyclic loading was computed by using the finite element code （ABAQUS） with the implementation of robust cyclic plasticity model. An incremental fatigue damage model was employed to calculate the fatigue damage. The formula of the fatigue crack propagation rate was directly derived from the fatigue damage criterion. Comparison of FE simulation and experiment results shows that the current simulations of crack growth are accordance with the results of the experiments. Both the numerical analysis and experimental data show that the fatigue crack propagation rate is insensitive to the stress ratio for plain stress thin specimens.
出处
《压力容器》
北大核心
2007年第3期1-7,共7页
Pressure Vessel Technology
基金
国家自然科学基金资助项目(50428504)
关键词
疲劳裂纹扩展
应力比
16MNR钢
疲劳损伤
有限元模拟
fatigue crack propagation
stress ratio
16MnR steel
fatigue damage
finite element simulation
