Stochastic analysis of inter- and intra-laminar damage in notched PEEK laminates

This paper presents a finite element model to predict the progressive damage mechanisms in open-hole PEEK (Poly-Ether-Ether-Ketone) laminates. The stochastic laminate's properties with non-uniform stress distribution are considered from element to element using the Gaussian distribution function. The failure modes considered are: fiber tension/compression, matrix tension/compression, fiber/matrix shear, and delamination damage. The onset of damage initiation and propagation are predicted and compared with three different failure criteria: strain-based damage criterion, Hashin-based degradation approach and stress-based damage criterion which is proposed by the authors of the present work. The inter-laminar damage modes associated with fiber/matrix shearing and delamination are modeled using the cohesive elements technique in ABAQUS (TM) with fracture energy evolution law. Mesh sensitivity and the effect of various viscous regularization factors are investigated. Damage propagation and failure path are examined by re-running the program for several times.