Date of Award

6-12-2018

Document Type

Thesis

Publisher

Santa Clara : Santa Clara University, 2018.

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

First Advisor

Michael Taylor

Abstract

It has been known that when introducing alternating elliptical extrusions in a solid material with a positive Poisson's Ratio, the material's effective Poisson's Ratio can become negative. Furthermore, the change in the effective Poisson's ratio depends on two factors: the elliptical extrusions' aspect ratio and the porosity. Using this phenomenon, a study is conducted by combining elliptical extrusions with different aspect ratios and porosity to construct a composite material with gradually varying Poisson's Ratio. Numerical and physical compression studies are conducted to characterize the material's effective properties. The results show that the material can effectively stabilize its own structure under unilateral loading and spread out reaction forces. These characteristics make graduating Poisson's Ratio materials good candidates for impact absorption applications. A brief look at a 3-dimensional auxetic structure is also conducted. A parametric modeling tool for the 3-dimensional structure is created.

Share

COinS