中文摘要：

针对核电一回路含缺陷主管道在内压波动、机械振动状况下,管道会产生明显的振动疲劳效应问题,建立了核电一回路含缺陷管道动态有限元模型研究动态特性对主管道疲劳裂纹扩展速率的影响。运用ABAQUS对核电一回路含缺陷主管道在静态内压和弯矩幅值下进行分析,得到静态裂纹应力强度因子及其前缘应力;然后对主管道在幅值相同的简谐循环载荷作用下进行分析,得到共振疲劳效应下的动态裂纹应力强度因子及其前缘应力;最后运用Paris公式分别得出静态与动态作用下疲劳裂纹扩展速率。研究结果表明：在内压及弯矩下,共振疲劳作用分别会提高裂纹最深点应力强度因子及其前缘应力50%-100%和16%-23%,同时二者分别会提高疲劳裂纹扩展速率将近5倍。

英文摘要：

With the obvious vibration fatigue effect of the pipeline induced by internal pressure fluctuation and mechanical vibration in the defective main pipe of a nuclear power line,the dynamic finite element model was established to study the influence of dynamic characteristics on fatigue crack growth rate of the main pipeline.The ABAQUS software was used to analyze the defective main pipeline under static pressure and bending moment amplitude conditions,and the static crack stress intensity factor and the front stress were obtained.Then the main pipeline under harmonic cyclic load with the same amplitude was analyzed and the dynamic stress intensity factor of crack and its front stress under the effect of resonant fatigue were also acquired.Finally the fatigue crack growth rate under static and dynamic actions was obtained using Paris formula.Results show that the resonant fatigue can respectively improve the crack stress intensity factor of the deepest point and its front stress by 50%-100% and 16%-23% under the condition of internal pressure and bending moment;meanwhile,the fatigue crack growth rate can be increased about 5times.