油管抗内压强度及爆破失效机理研究

Study on Collapse Strength and Failure Mechanism of the Tubing Under Internal Pressure

利用水压试验机对油管进行爆破试验,检测在爆破过程中油管外壁的应变变化。运用弹塑性力学理论建立模拟油管爆破过程的有限元模型,得到油管外壁应变随内压变化的曲线,并与试验值对比,从而探索油管爆破的失效机理。结果表明,油管爆破过程中,壁厚较薄处首先产生较大的应变进而造成油管在此处爆裂。利用有限元法进一步分析发现,与管体椭圆度相比,壁厚不均度对油管抗内压强度影响较为显著。将有限元模拟与应变测试结合起来以提高有限元模拟的精度,对研究油管爆破失效机理、预测油管抗内压强度具有一定的参考价值。

The blasting test of the tubing is carried out by using the hydraulic testing machine,and the strain change of the outer wall of the oil pipe is detected during the blasting process.Using the theory of elastoplastic mechanics,a finite element model for simulating the blasting process of tubing was established,and the curve of the strain of the outer wall of the tubing changing with the internal pressure was obtained.Compared with the test value,the failure mechanism of tubing blasting was explored.During the blasting process of tubing,the thin part of the pipe wall first produces a large strain and causes the tubing to burst.Further analysis using the finite element method found that,compared with the ovality of the pipe body,the unevenness of the wall thickness has a more significant effect on the internal pressure resistance of the tubing.Combining the finite element simulation with the strain test to improve the accuracy of finite element simulation has certain reference value for studying the failure mechanism of tubing blasting and predicting the internal pressure resistance strength of tubing.