Multiscale Failure Analysis of Cylindrical Composite Pressure Vessel: A Parametric Study

This paper deals with a multiscale approach to model thick-walled laminate cylinder with internal pressure. Micromechanics defines material homogenization considering two steps: determination of equivalent properties of each lamina from matrix and fiber properties according to the Mori-Tanaka model for elastic properties and to the Bridging model for strengths; and determination of anisotropic homogeneous properties of the laminate built with a set of laminae using asymptotic homogenization. On the other hand, macromechanics determines stress and failure analysis. Lekhnitskii formalism is used to obtain the elastic solution of the stress and strain distributions and failure is analyzed employing the Tsai-Wu criterion. Three different pressure vessel configurations are analyzed according to end conditions: restrained-ends, open-ends and closed-ends. Angle-ply laminates made of carbon fibers and epoxy matrix are considered to evaluate the influence of lay-up angle, fiber volume fraction, wall thickness and end-conditions. The optimum angles as well as the maximum internal pressure are obtained and a parametric analysis is presented. The main results indicate that the optimum angle is almost constant for restrained and closed-ends. On the other hand, for open-end, angle varies in a significant way. Besides, results show that the increase the fiber volume fraction is more effective to increase vessel strength than the increase of the number of layers.