Ellipsoid Defect Of Mechanical Properties Of Pe Gas Pipeline Is Influenced By Temperature

In recent years, with the rapid economic development of our country, people demands of the environment and material culture become more and more important, continuous natural gas production and applications will promote the rapid development of natural gas industry the of natural gas industry. Polyethylene tubing (PE) has good corrosion resistant performance, simple welding, the advantage of long life; all these advantages make utilization of PE pipe in the gas industry more and wider and wider. In recent years, according to the gas accident incomplete statistics found that, for a third party caused by the destruction of the accident rates as high as54.54%. In the process of PE pipe Pipe lying, the requirements for soil are not conformed, and its defects are also common. People often ignore incomplete destroy in the outer wall of pipeline polyethylene pipe load change of temperature when the pipe stress influence.This paper is based on the phenomenon of people insufficient attention defect in temperature load change on pipeline polyethylene tubing stress has great influence to the PE, and put forward the thermal stress of finite element software ANSYS analysis function analysis the stress changes PE. This study select PE80, SDR11, and approxi--mate oval defects for example, as the different season the different temperature chan--ges of outer wall of pipeline, Wall for15℃fixed load, and build a reasonable heat stress model, analysis thermal stress that PE pipe in coupled map different load and different defects of stress at the trend changes.This research concludes that complete pipe outside wall temperature for30℃of the outer wall of the stress is bigger than the ratio for10℃temperature; When the pipe is in the inside and outside temperature load and seriousness of wall thickness ratio are the same, the stress is not getting increased gradually as the angle of α magnify. The greater the angle of a, the less stress to surface value defects in its pipeline; Pipe load of inside and outside and the angle of a are the same, the proportion of the degree of defects of wall thickness bigger, the stress bigger.This paper through the finite element software the thermal-stress coupling method, simulate the PE pipe all the stress of the state,combined with actual data of PE pipe effected by temperatu re performance accurately analysis, and give the ministry of construction on-the polyethylene gas pipeline engineering technology regulation on5.1.1section of the gas industry standard related perfect opinion Strengthen the gas industry personnel attention of surface bei--ng not completely PE destroyed to pipe network safe operation of the potential harm brought important know, from gas network of layout of pipeline network construction to the normal operation of the can take enough measures, reducing gas pipeline transport accident maxim--um guarantee the safety of project of people’s livelihood, the maximum economic benefit the society to safe.