Numerical analysis of displacement and stress fields of off-axis composites in three-point flexure

Abstract

Three-point flexure test for unidirectional off-axis composites has been analyzed by the finite element method. The main difficulty of modeling three-point flexure test of this kind of material is due to the bending-twisting coupling that induces the lift-off of the specimen at the fixture supports. In the present work, the contact between the load and support rollers and the specimen has been modeled with linear gap elements. The type of element and refinement of the mesh have been analyzed in order to minimize numerical error. After having selected those parameters, a complete model with discretization of load and support rollers has been developed to simulate different test conditions. The numerical displacement field has been compared with analytical and experimental results obtained previously. Furthermore, the length and location of the contact between specimen and rollers has been numerically predicted in some configurations.