Abstract：In this paper, the liner buckling and collapse of bi-material metal pipes subjected to combined loadings 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 outer pipe diameter, 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 influence on the buckling of bi-material metal pipes under combined loadings. Reducing the diameter of the outer steel pipe, the annular gap between the liner pipe and the outer steel pipe and the yield stress of the liner pipe can increase the curvature of liner buckling of the bi-material metal pipes. Increasing the wall thickness of the liner pipe and the internal pressure can delay the liner collapse. Thus the liner buckling and collapse of bi-material metal pipes subjected to combined loadings have become one of the important parts in the pipeline system design and the conclusions in this paper could be used to support the technical design and the safety assessment of the bi-material metal pipes.
2019, Vol. 40 
