Title

3D Textile PMC damage evolution : effects of fiber volume fraction and morphology variation

Date of Award

2016

Degree Name

M.S. in Mechanical Engineering

Department

Department of Mechanical and Aerospace Engineering

Advisor/Chair

Advisor: Margaret Frances Pinnell

Abstract

3D textile polymer matrix composites (PMC) exhibit geometric and material state variances due to differences in manufacturing processes and a variety of other factors. Developing a more thorough understanding of these strength and damage variations is a vital aspect of generating an accurate predictive model for the material response of a 3D textile PMC. This work entails both experimental and modeling efforts in order to gain a more thorough understanding of how tow level geometric variations relate to damage evolution in a 3D textile PMC. A 3D orthogonal weave textile is imaged utilizing an X-Ray micro-CT to examine the fiber volume fraction and fiber path distributions within the composite. Additionally, damage evolution is observed at different load steps and CT images are utilized for Digital Volume Correlation analysis. Modeling efforts are primarily focused on tow morphology simulations within the software package- Virtual Textile Morphology Suite (VTMS). Damage evolution analysis on the VTMS models are performed using an advanced Regularized eXtended Finite Element Method (RX-FEM) within the Air Force Research Laboratory developed B-Spline Analysis Method (BSAM) program. Local fiber volume fraction variation in the specimens is examined through serially sectioned images obtained using Robo-Met 3D. Fiber volume fraction distributions are compared to VTMS predictions and VTMS predictions are modified to reflect experimental values. The effect of these local fiber volume fraction distributions on damage evolution in the composite are examined through experimentation and modeling efforts.

Keywords

Polymeric composites Deterioration Testing, Strength of materials Simulation methods, Engineering, Mechanical Engineering, Materials Science, Mechanics, 3D Textile Polymer Matrix Composite, Fiber Volume Fraction Variation, Discrete Damage Modeling, Textile Morphology Variation, Inter-tow Property Variation, Tow Fiber Path Distribution

Rights Statement

Copyright 2016, author

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