Identifier

etd-10262010-153502

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

Two groups of nanoindentation experiments, including repeated loading tests and monotonic loading tests, were performed on muscovite with a sharp indenter tip and loading direction normal to the basal plane. By varying the maximum load in the first group of repeated experiments, influences of the load level can be examined on the modes of nanoscale deformation and the resulting estimation of hardness and elastic modulus. The incipient kink band concept was employed to interpret the observed dispersed loading-unloading hysteresis loops by considering formation and annihilation of IKBs. Furthermore, the material’s contact stiffness behavior was characterized by comparing the normalized unloading section of the loading-unloading loops of each test. Then a group of strain rate controlled monotonic loading tests was conducted for further comparison and evaluation of strain hardening effects of muscovite introduced by previously cyclic loading process. The second objective of these experiments was to discuss the indentation size effect, which usually occurred in micro scale indentation tests, and propose a proper model that can simulate the occurrence of pop-ins as well as its degrees.

Date

2010

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Zhang, Guoping

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