管道轴向双裂纹夹角对尖端应力强度因子的影响

Influence of Double Axial Cracks' Angle on Stress Intensity Factors of Crack Tip

管道裂纹应力强度因子的分析是裂纹是否扩展判断和管道疲劳断裂计算的关键.应用通用有限元软件ANSYS对不同管道外径、裂纹尺寸、不同夹角下含轴向双裂纹管道裂纹尖端应力强度因子进行了计算.结果表明,管道和裂纹尺寸确定时,裂纹尖端应力强度因子随裂纹间夹角增大而增加;管道尺寸确定时,随着裂纹长与壁厚比增加,夹角对裂纹尖端应力强度因子影响增强.通过分析夹角对双径向裂纹应力强度因子的影响,为工程实际中合理地判断裂纹扩展可能性和精确地进行管道疲劳断裂计算提供参考.

Stress intensity factor analysis of pipe cracks is the key to determine whether there exists crack propagation and to calculate the pipe fatigue fracture.The stress intensity factors at the double axial cracks＇ tip of pipes with different size,crack length and angles between cracks were calculated by universal finite element software ANSYS.The calculation results indicated that the stress intensity factor increases with increasing the angle between double axial-through cracks when the pipe size and crack dimensions are determined.The influence of angle between cracks on stress intensity factor is enhanced with increased ratio between crack length and pipe thickness at defined pipe size.The analysis may provide certain reference information for reasonable determination of the crack propagation and accurate calculation of the pipes＇ fatigue fracture.