The Prediction of Multi-scale Voids and Their Mechanical Ef- fect on Thick Composite Struc- tures Manufactured by RTM

Thick composite laminates can be used in aerospace and automotive industry replacing metals for weight saving. Increasing the thickness can bring more defects, like voids. This master thesis focuses on the multi-scale voids prediction and their mechanical effect simulation of thick composite laminates manufacturing by Resin Transfer Molding (RTM). It could be potentially used in safe design of thick composite components. The main objective of the thesis work is to analyze the effect of multi-scale voids caused by the filling process on mechanical properties of thick composite laminates. First is using PAM-RTM to simulate the locations of voids and their percentage. Then, the material properties of each Microstructural Volume Element (MVE) with different micro and macro voids are evaluated by Digimat at micro and meso scales. After that, the macroscale material properties of the thick laminates are simulated in ABAQUS. The simulation processes are verified by using the parameters from the literature and then comparing with the published results. The simulation from PAM-RTM indicates the average void percentage of the whole laminate reduces with the increasing injection pressure or permeabilities. The total void volume increases with an increasing laminate thickness but the average void volume does not change with the changing thickness. The result of this thesis suggests that the effect of multi-scale voids on material properties (i.e., Young’s modulus, Poisson’s ratio, and Shear modulus) does not change due to an increasing thickness. The writing presents the actions taken in order to achieve the objective of the research successfully.