基于非线性环理论的管道上卷弯曲屈曲分析

摘要

基于非线性环理论和虚功原理,建立了管道截面应力和应变之间的平衡方程,并通过迭代法对方程进行求解,得到了弯曲过程中管道变形及弯矩.以Φ0.168 0 m(6英寸)管道为例进行了分析,并将理论值与试验和仿真结果进行了比较,其误差在施工允许范围内,验证了本文方法的正确性.采用本文方法对Φ0.406 4 m(1 6英寸)管道上卷屈曲影响因素进行了研究,结果表明:径厚比越小,管道的弯矩承载能力和抗扁化能力越强;硬化指数越大、屈服强度越小,管道的抗扁化能力越强;硬化指数对弯矩承载能力影响较小,屈服强度直接影响管道弯矩承载能力;弹性回弹降低了管道的椭圆度.%The balance equation between the pipe's cross section stress and strain was established based on the nonlinear ring theory and principle of virtual work.The pipe's cross section deformation and bending moment in bending process were obtained by solving the equations with iteration method.Φ 0.1680 m(6-inch)pipe was analyzed as an example,and then the theoretical values were compared with the simulation and test results. The error is within the allowable range for construction,showing that the method is correct.Finally,the in-fluence factors of pipe buckling were studied with Φ0.4064 m(16-inch)pipe in reeling by our method. Some conclusions were achieved:1)the smaller the ratio of diameter to thickness,the stronger the pipe bending bearing capacity and anti-ovalization ability;2)the smaller the yield strength,and the lager the hardening index,the stronger the pipe anti-ovalization ability;3)the hardening index has little influence on the pipe bending bearing capacity,and yield strength directly affects the capacity;and 4)the elastic spring-back reduces the ovality of the pipe.