A novel non-linear orthotropic constitutive model with deformation induced fiber reorientation effect for composite laminate simulation

Fiber reorientation plays an important role in the mechanical behavior of composites, since this phenomenon is independent from the applied constitutive laws and can lead to stiffer or softer nature. Previous general approaches have been relied on the small time step size to model such effect in explicit simulations. A novel non-linear in-plane elastic constitutive model is developed for continuous fiber reinforced laminates to account for this problem. The model consists of a non-linear elastic constitutive model with distinguished tensile and compressive behavior along with deformation induced fiber reorientation, which is not handled by the finite element formulations and extended for implicit approach as well. The proposed material model is also implemented as a user-defined material subroutine in the commercial finite element software LS-DYNA. The implementation includes both explicit and implicit formulation approaches for thin shell and solid elements, respectively. Moreover, the proposed material model is also validated via simulations of measurement results performed on Toray Cetex ® TC1225 - Standard Modulus Carbon 145 gsm UD Tape 34% RC and glass fiber reinforced polyester materials.