Hi-fidelity finite element models with physically based failure criteria are now well established for fiber reinforced composites, giving good accuracy at standard room temperature conditions. However, the mechanical properties of fiber reinforced composites, especially the matrix and fiber/matrix interface are sensitive to in-service conditions such as, temperature and humidity. These degradation effects are rarely accounted for in predictive failure models and have only thus far been presented as either independent temperature or moisture models. No effective and comprehensive failure models or criteria exist for hot-wet conditions. In this work, a semi-empirical model based on Zhurkov’s kinetic theory was developed for hygro-thermal strength degradation of both the composite plies and interfaces of a thermoset epoxy laminate along with empirically based models for stiffness and fracture energy. These models were implemented in a Continuum Damage Model (CDM) based user material subroutine in the Abaqus Explicit finite element software, and validated against experimental data available in the literature for various configurations. The simulation of open hole tensile test of room temperature dry (RTD) and elevated temperature wet (ETW) specimens are carried out. The predicted strength values are within the error limits of the experimental data. For this specific configuration, ETW strength increases (~12%) from RTD due to the hygro-hermal residual stresses of interface and matrix. Othercases, such as in-plane shear and short beam strength show considerable knock down.
|Number of pages||1|
|Publication status||Published - 18 Sep 2019|
|Event||7th ECCOMAS Thematic Conference on Mechanical Response of Composites - University of Girona, Girona, Spain|
Duration: 18 Sep 2019 → 20 Sep 2019
|Conference||7th ECCOMAS Thematic Conference on Mechanical Response of Composites|
|Period||18/09/19 → 20/09/19|