Degree Type

Thesis

Date of Award

2016

Degree Name

Master of Science

Department

Mechanical Engineering

Major

Mechanical Engineering

First Advisor

Gap-Yong Kim

Abstract

Metal matrix composites (MMCs) have been widely used in various industries including aerospace, automotive, transportation, etc. While many types of MMCs have been studied and developed, including reinforcement phases of mono filaments, short/long fibers, and particles, their arrangement within the matrix has been rather simple. In this study, a finite element simulation tool has been used to study laminate composites with complex configurations. A finite element analysis has been performed to understand the strengthening effect of pattern-reinforced composite structure using a small punch test. It was found that the pattern reinforcement helped to distribute stress and strain during deformation. This resulted in the strength increase of 40% when compared with a uniform alternating layer-reinforced composite. Furthermore, composites with three different pattern sizes of 2 µm, 20 µm and 50 µm with the same reinforcement loading were compared. The smallest pattern showed the highest strength compared with larger patterns by 30% and 60%. Furthermore, the influence of elastic modulus, yield strength, ultimate strength, and fracture strain on the four deformation stages of the small punch test has been analyzed. Based on the analysis, a modified energy dissipation equation was developed to compensate for variations originating from the sheet thickness and the test ball size.

This study helps to explain the strengthening effect from a pattern-reinforced laminate composite in comparison with the uniform alternating layer-reinforced structure. It demonstrated potential ways to alter or tailor mechanical properties of laminate composites and to further optimize the configuration of custom designed laminate composites.

Copyright Owner

Miao Liu

Language

en

File Format

application/pdf

File Size

52 pages

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