Prediction of the mechanical behavior of flax polypropylene composites based on multi-scale finite element analysis

Abstract

Natural fibers and their composites differ in several aspects with carbon fibers, including higher scatter in strength and different tensile responses. The tensile and bending properties of flax fiber composites were experimentally studied and numerically simulated. Composite panels were fabricated from unidirectional flax fiber tapes and polypropylene films via hot pressing technique. The variation in the properties of flax/polypropylene composites was found to be relatively moderate as compared with that of single natural fibers. A multi-scale finite element analysis (FEA) strategy for the progressive damage prediction of natural fiber composites was developed. The FEA model started from microscale analysis which predicted the effective properties of unidirectional flax ply through representative volume element. Macro-scale analysis was conducted subsequently to predict the properties of composite coupons using the results of micro-scale analysis as inputs. The developed multi-scale FE model successfully predicted the tensile strength, bending behavior, and major failure modes of flax/polypropylene composites.

Fiber/matrix interface stress analysis of flax-fiber composites under transverse loading considering material nonlinearity

“…Other studies generally have two methods to model the flax fiber, which are based on linear elasticity with orthotropic properties 7,10,11,[28][29][30][31] and nonlinear inelasticity. 10,32,33 In this study, nonlinear inelastic case is not considered due to lack of 4th order strain potential parameters for the material itself.…”

“…The numerical model results showed a good agreement with the experimental results. Zhong et al 11 used experimental and numerical techniques to investigate tensile and bending properties of natural fiber composites. They carried out experiments and finite element model simulations based on unit cells to predict the material behavior, taking into account the damage in the fiber/matrix interface.…”

Finite element models of natural fibers and their composites: A review

“…Zhong et al. 82 developed multi-scale RVEs for the progressive damage prediction of flax PP composites. A micro-scale RVE of unidirectional flax fiber composites, as shown in Figure 9 (a), was built first to predict the effective properties of the material including elastic constants and strength.…”

“…(a) Representative volume element of a unidirectional flax fiber composite, 82 (b) layer combination and mesh of the glass-jute reinforced laminated composite, 8 and (c) representative volume element model of a flax fiber fabric composite. 75 …”

Grid nano-indentation as full-field measurements

“…• The first is based on the adjustment of the macroscopic experimental mechanical response, using a model that takes into account this supplementary phase in a representative volume element (RVE) [6,7]. This strategy is essentially numerical but it requires the knowledge of the mechanical behavior of the phase.…”