Constitutive model for fibre reinforced composites with progressive damage based on the spectral decomposition of material stiffness tensor

Complex nature of the fibre reinforced composites, their non-homogeneity and anisotropy make modelling a challenging task. Although linear – elastic behaviour composites is well understood, there still significant uncertainty regarding prediction damage initiation, evolution material failure especially for general loading case characterised with triaxial state stress or strain. Consequently, simplifying assumptions are often unavoidable in development constitutive models capable accurately predicting damage. The approach used this work uses decomposition strain energy based on spectral stiffness tensor an assumption that each component represent free characteristic deformation mode. criteria initiation corresponding to mode triggered when exceeds specified critical limit. In proposed model modes not interacting at continuum scale due orthogonality eigenvectors, i.e. symmetry. Damage its modelled by reduction principal effective concept hypothesis equivalence. was implemented into Lawrence Livermore National Laboratory (LLNL) Dyna3d explicit hydrocode coupled vector shock Equation State. verified validated series single element tests, plate impact test high velocity hard projectile aerospace grade carbon plastic. predicted response including cases presence waves, e.g. test. It also demonstrated delamination simulation where numerical results were within 5% post experimental measurements.