Bending Moment Capacity of Defected Pipes Subjected to Combined Loads

摘要

The main object of this study is the investigation of bending moment capacity for groove corroded metallic pipes by introducing an analytical solution. The pipeline may be subjected to combination loads including pressure, longitudinal force and bending during their life time. Additional to considering these loads, the corrosion defect should be included in designing of the pipelines, which are used for transportation of corrosive fluid. In order to calculate the bending moment capacity of such pipelines, in this paper an analytical solution has been developed to consider the interaction between pressure, longitudinal force and bending moment along with the corrosion situation. Also, the derived analytical solution has been thoroughly compared with the results which are obtained by using the finite element method. This work provides a set of equations for calculating the maximum allowable bending moment as a function of initial out-of-roundness, longitudinal force, internal/ external overpressure and corrosion depth, width and length together. The equations can be used for materials with isotropic as well as anisotropic stress/ strain characteristics in the longitudinal and hoop direction.