Heckman, David: Finite element analysis of pressure vessels, MBARI 1998 Finite Element Analysis of Pressure Vessels

Pressure vessels are a commonly used device in marine engineering. Until recently the primary analysis method had been hand calculations and empirical curves. New computer advances have made finite element analysis (FEA) a practical tool in the study of pressure vessels, especially in determining stresses in local areas such as penetrations, O-ring grooves and other areas difficult to analyze by hand. This project set out to explore applicable methods using finite element analysis in pressure vessel analysis. Having tested three dimensional, symmetric and axisymmetric models, the preliminary conclusion is that finite element analysis is an extremely powerful tool when employed correctly. Depending on the desired solutions, there are different methods that offer faster run times and less error. The two recommended methods included symmetric models using shell elements and axisymmetric models using solid elements. Contact elements were tested to determine their usefulness in modeling the interaction between pressure vessel cylinder walls and end caps. When modeled correctly, contact elements proved to be useful, but the operator also needs to be able to interpret the results properly. Problems such as local stress risers, unrealistic displacements and understanding how to use such data become extremely important in this kind of analysis. This highlights the key to proper use of finite element analysis. The analyst should be able to approximate the solution using classical methodology (hand calculations) in order to verify the solution