Pipe Response Under Concentrated Lateral Loads and External Pressure

The paper focuses on the denting the response of pipeline segments subjected to lateral quasi-static wedge loading, in the presence of internal pressure. Nonlinear finite element models of pipeline segments, which are in good agreement with denting test data from internally pressurized pipes, are employed to obtain load-deflection curves for different levels of pressure, for various wedge shapes and for different types of boundary conditions. It is found that the presence of internal pressure increases significantly the denting resistance. The present study gives special emphasis on the development of a simplified three-dimensional analytical model, which yields closed-form expressions for the denting force and the corresponding denting length in terms of the corresponding denting displacement. The model, introduced elsewhere for non-pressurized tubes, is enhanced to include the pressure effects, accounting for different types of pipe end conditions. The analytical solution compares very well with the finite element results, and illustrates tube denting response in a clear and elegant manner.