Application of the Stiffness-Force method in the analysis of the fiber-matrix adherence in composite laminates

Abstract

This work shows the analysis of the adherence of a fiber embedded in the matrix by the Stiffness-Force method (SFM) in Finite Elements. The formulation of the SFM method takes into account not only the equilibrium equations but also the compatibility conditions, obtained from the principles of the virtual work and complementary virtual work. For the finite element analysis using the SFM method a user subroutine (UEL) of a four node axisymmetric quadrilateral element has been formulated, and has been implemented in the commercial code Abaqus. In a first step the specimen has been analyzed by Abaqus, which uses the stiffness method in its formulation. Then the same model has been analized by the user subroutine which uses the SFM method. Finally, the results obtained by both analysis have been compared with varying degrees of discretization.