残余应力对高强度钢管外压稳定性的影响

Effect of Residual Stress on Stability of High Strength Steel Pipe under External Pressure

压力钢管外压失稳破坏与材料的强度、初始缺陷和初始应力密切相关。在实际工程中,通常将出厂的短钢管通过焊接的方式拼接为长钢管进行使用,这就导致了焊接残余应力的存在。为了在工程上较为简单地计算具有残余应力的压力钢管的临界失稳荷载的大小,本文采用有限元技术,针对Q355NC和Q460D两种钢管,将残余应力考虑为初始应力场,通过ANSYS,计算出具有不同焊接残余应力的压力钢管的临界外压大小,同时,以钢材的强度为参数,进行了相同残余应力水平下钢管临界外压的敏感性分析。

The external pressure instability failure of pen-stocks is closely related to the strength,initial defect and initial stress of the material.In practical engineering,short steel pipes are usually welded into long steel pipes,which leads to the existence of welding residual stress.In order to calculate the critical buckling load of pen-stocks with residual stress more simply in engineering,this paper have adopted finite element technology,and for Q355NC and Q460D steel pipes,the residual stress has been considered as the initial stress field.Through ANSYS,the critical ex‐ternal pressure of pen-stocks with different welding residual stresses has been calculated.At the same time,using the strength of the steel as a parameter,the sensitivity analysis of the critical external pressure of the steel pipe under the same residual stress level has been carried out.