A continuum damage mechanics model for fatigue and degradation of fiber reinforced materials

Abstract

Objective of the present study is the definition of a continuum damage mechanics material model describing the degradation of fiber reinforced materials under fatigue loads up to final failure. Based on the linear elastic framework, a brittle damage model for fatigue conditions is derived, where the damage constitutes the only nonlinearity. The model accounts for damage effects by successive degradation of the elastic moduli. Assuming that material damage is driven by microplastic work, a stress-driven damage evolution equation is defined. For generality, a fully three-dimensional formulation on single ply level is employed. The model is implemented into a finite element program. In a validation against experimental data on filament-wound carbon fiber reinforced material, the model proves to provide a good numerical approximation of the damage during the cyclic loading history up to final material failure.

A Continuum Damage Mechanics-based Piecewise Fatigue Damage Model for Fatigue Life Prediction of Fiber-Reinforced Laminated Composites

“…degradation growth function [45]. In this study, the introduced model is called the piecewise fatigue damage model (PFDM), which can fit each of the degradation phases.…”

“…To validate the proposed model, they utilized the experimental method and showed that considering static damage under the cyclic loading process is necessary. Hohe and his colleagues [45] assumed that the damage of material results from microplastic work and defined a brittle damage model based on the CDM approach that describes the degradation of the laminate composite under harmonic cyclic loading.…”

In-Service Delaminations in FRP Structures under Operational Loading Conditions: Are Current Fracture Testing and Analysis on Coupons Sufficient for Capturing the Essential Effects for Reliable Predictions?

“…In these approaches, element properties are progressively degraded, rather than explicitly modelling the physical damage (see, e.g., Refs. [73][74][75][76]). Recently, the US Air Force Research Laboratory benchmarked the performance of seven different models against experimental data [77].…”