压弯载荷下底部减薄三通塑性极限载荷分析

采用有限元分析软件ANSYS,对常见等径三通进行数值模拟分析,求得内压与弯矩联合作用下的塑性极限载荷有限元解;研究了不同比例内压、面外弯矩联合载荷作用下,底部减薄尺寸对三通失效模式和极限承载能力的影响。研究结果表明,无量纲化的底部减薄深度c≥0.4时,缺陷的存在才会对三通极限承载能力有显著影响。内压较大时,轴向减薄尺寸是造成底部塑性失效的主要因素。通过对大量算例的拟合,提出了压弯联合载荷作用下含底部减薄三通的塑性极限载荷工程估算公式。

Analysis of plastic limit loads of tee with bottom wall-thinning under pressure and moment

In this paper, the FEA software-ANSYS is used to carry out the numerical simulation analysis of common equal-diameter tees and obtain the finite-element solution of plastic limit loads under the collaborative action of internal pressure and out-of-plane moment. The influence of the combined load ratio and bottom wall-thinning sizes on the failure modes and the plastic limit loads of tees is investigated. The results show that the defects have great effect on the plastic limit loads of tees when bottom wall-thinning depth c is greater than or equal to 0.4. Axial size is a main factor of bottom plastic failure if internal pressure is greater than moment. Finally, according to the numerical results of plentiful FE models, the engineering estimation equation for the plastic limit combined load of tees with bottom wall-thinning is presented.