Best Theory Diagrams for Laminated Composite Shells Based on Failure Indexes

Abstract

This paper presents a novel approach to developing 2D structural theories for composite shells. The proposed approach uses the capabilities of the Carrera Unified Formulation (CUF) in conjunction with the Axiomatic/Asymptotic Method (AAM) to obtain the best theories for given structural layouts. Different structural cases are considered to analyze the influence of factors such as boundary conditions, lamination, and thickness on the accuracy of a model. The parameter chosen to evaluate a model’s performance is based on the Failure Indexes (FI) defined by the Hashin Failure criteria for unidirectional fiber composites. The outcome of this procedure is the Best Theory Diagram (BTD), containing the graphical representation of the highest accuracy as a function of the number of adopted unknowns. The results show the importance of higher-order terms to capture stress fields and the influence of thickness on the definition of the best theories.