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

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.