环焊缝对管道系统跨距的影响

Effect of Circumferential Weld on Piping System Span

为了研究环焊缝对管道系统强度的削弱作用,对管道的环焊缝应力状态进行分析,得出管道环焊缝处强度主要由自重以及外载产生的轴向弯曲应力控制。管道跨距是决定轴向弯曲应力的主要变量,参照第一强度理论计算方法,通过引入环向焊接接头系数来考虑环焊缝对管道的跨距值的削弱作用,将计算值与现有标准规范中的管道跨距设计值相比较,并分析环焊缝处应力超标的发生条件。不考虑环焊缝的削弱进行管道跨距设计,某些情况下跨距值是不安全的。从设计角度给出了避免环焊缝应力超标的建议。

In order to study the weakening effect of circumferential weld on piping system,the stress state of circumferential weld was analyzed.It was concluded that the strength of circumferential weld of piping was mainly controlled by the axial bending stress produced by self-weight and external load。Pipe span was the main variable reason to determine the axial bending stress.Referring to the first strength theoretical calculation method,the weakening effect of circumferential weld on the span of piping was considered by introducing circumferential weld joint coefficient,and the calculated span value was compared with the design value of pipe span in the existing standard specification.The occurrence conditions of over stress at circumferential weld were analyzed.In pipe span design without consideration of circumferential weld weakening,the span value was not safe in some cases.Suggestions to avoid excessive stress of circumferential weld were given from the point of view of design.