复杂载荷下双金属复合管的屈曲失效研究

In this paper, the liner buckling and collapse of bi-material metal pipes subjected to combined loading are studied systematically by using the finite element method. A 3-D finite element model is developed by considering the residual stress produced in the quasi-static inflation process. The effects of various parameters, such as the diameter of the outer pipe, the wall thickness of the liner pipe, the initial gap between the outer pipe and the liner pipe, the yield strength of the liner pipe, the internal pressure, and the friction between the outer pipe and the liner pipe on the liner buckling and collapse of bi-material metal pipes are analyzed in detail. It is found that the loading path, the geometric dimension and the yield strength of the liner pipe have significant influences on the buckling of bi-material metal pipes under combined loading.A decrease in the diameter of the outer steel pipe, the annular gap between the liner pipe and the outer steel pipe, or the yield stress of the liner pipe can increase the curvature of liner buckling of the bi-material metal pipes. An increase in the wall thickness of the liner pipe or the internal pressure can delay the liner collapse.The liner buckling and collapse of bi-material metal pipes subjected to combined loading have become an indispensable part in the design of pipeline systems, and the conclusions in this study can thus be used to support the technical design and safety assessment for bi-material metal pipes.