A Multiscale Modelling Approach for Estimating the Effect of Defects in Unidirectional Carbon Fiber Reinforced Polymer Composites.

Kim-Niklas Antin,Pedro Vilaça,Danny Smyl,Tom Andersson,Anssi Laukkanen

doi:10.3390/ma12121885

Abstract

A multiscale modelling approach was developed in order to estimate the effect of defects on the strength of unidirectional carbon fiber composites. The work encompasses a micromechanics approach, where the known reinforcement and matrix properties are experimentally verified and a 3D finite element model is meshed directly from micrographs. Boundary conditions for loading the micromechanical model are derived from macroscale finite element simulations of the component in question. Using a microscale model based on the actual microstructure, material parameters and load case allows realistic estimation of the effect of a defect. The modelling approach was tested with a unidirectional carbon fiber composite beam, from which the micromechanical model was created and experimentally validated. The effect of porosity was simulated using a resin-rich area in the microstructure and the results were compared to experimental work on samples containing pores.

Highlights

Fiber-reinforced polymers are important materials for structural applications in many fields.For example, there are several notable applications of unidirectional (UD) carbon fiber reinforced polymers (CFRP) in civil engineering [1,2,3,4]
Micromechanical models can be divided into phenomenological models, such as shear lag and fiber bundle models [12], and numerical models using the finite element method (FEM) [9]
Both types of micromechanical models take into account the interactions between fiber and matrix, only numerical models have the potential to fully capture the complex nature of damage evolution in composites [13]

Summary

Introduction

Fiber-reinforced polymers are important materials for structural applications in many fields.For example, there are several notable applications of unidirectional (UD) carbon fiber reinforced polymers (CFRP) in civil engineering [1,2,3,4]. Micromechanical models can be divided into phenomenological models, such as shear lag and fiber bundle models [12], and numerical models using the finite element method (FEM) [9] Both types of micromechanical models take into account the interactions between fiber and matrix, only numerical models have the potential to fully capture the complex nature of damage evolution in composites [13]. They have the capability of accurately describing how failure starts and how defects that are small compared to the microstructural features affect the performance of a composite

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