动态车载下埋地聚乙烯燃气管道力学响应特性

Mechanical Response Characteristics of Dynamic Vehicle-mounted Buried Polyethylene Gas Pipeline

车载作用下,埋地含缺陷聚乙烯燃气管道易发生应力集中,这会加速管道的破坏而导致事故的发生。建立了车-管-土三维非线性耦合模型,加载车载类型为动态车载,除重量、内压和缺陷深度外,还重点探究了车速与管道力学响应之间的内在联系,并对不同车速和内压下的路面极限载荷进行了评估。结果表明:含缺陷管道应力明显大于无缺陷管道应力;土体自重在一定程度上能够抑制内压对管道的作用效果;管道最大Mises应力与缺陷深度系数、车载、内压大小成正比,与车速成反比。对含缺陷管道应力集中影响程度为:内压>缺陷深度>车载>车速;无缺陷管道的极限载荷高于含缺陷管道,内压对含缺陷管道的极限载荷影响最大,其次是缺陷深度和车速。

Under vehicle-mounted action,buried polyethylene gas pipelines containing defects are prone to stress concentration,which will accelerate the damage of pipelines and lead to accidents.A three-dimensional nonlinear coupling model of vehicle-tube-soil was established,and the loading vehicle type was a dynamic vehicle.In addition to weight,internal pressure,and defect depth,the internal relationship between vehicle speed and pipeline mechanical response was also explored,and the ultimate road load under different vehicle speeds and internal pressures was evaluated.The results show that the stress of pipes with defects is greater than that of pipes without defects.The soil weight can inhibit the effect of internal pressure on the pipeline to some extent.The maximum Mises stress of the pipeline is positively proportional to the defect depth coefficient,vehicle-mounted and internal pressure,and inversely proportional to the vehicle speed.The degree of influence on stress concentration of pipes with defects is as follows:internal pressure>defect depth>vehicle speed>vehicle speed.The ultimate load of the non-defective pipeline is higher than that of the defective pipeline,and the internal pressure has the greatest influence on the ultimate load of the defective pipeline,followed by the defect depth and speed.