海底悬跨管道表面双裂纹数值分析

为了研究海底油气管道多个裂纹间相互作用对管道产生的影响，针对海底悬跨管道表面双裂纹的相互作用，采用有限元方法建立双环向表面裂纹模型，采用围道积分法求解双裂纹下的应力强度因子，研究了不同边界条件下，不同尺寸裂纹间的相互影响规律，并对比了单裂纹下应力强度因子的变化情况。研究结果表明:不同尺寸的裂纹对双裂纹的相互影响规律有一定影响，且双裂纹应力强度因子最大值均出现在裂纹最深点处；弹簧边界下双裂纹相互影响规律与简单边界下相互影响规律明显不同；不同边界条件对悬跨管道双裂纹应力强度因子的影响较大。研究结果可为海底悬跨管道的失效分析提供参考依据。

Numerical analysis of double cracks on surface of seabed spanning pipeline

In order to study the effect of the interaction between multiple cracks on the seabed oil and gas pipeline, aiming at the interaction of double cracks on the surface of seabed spanning pipeline, a model of double circumferential surface cracks was established in the finite element software, and the stress intensity factors of double cracks were calculated by using the contour integration method. The interaction between the cracks with different sizes under different boundary conditions was studied, and the variation of stress intensity factor was compared with that of single crack. The results showed that different sizes had a certain influence on the interaction of double cracks, and both the maximum values of stress intensity factors of double cracks appeared at the deepest point of the cracks. The interaction of double cracks under the spring boundary was significantly different from that under the simple boundary, and different boundary conditions had a greater influence on the stress intensity factor of double cracks for the spanning pipeline. The results can provide the reference for the failure analysis of the seabed spanning pipeline.