Title page for ETD etd-06142010-095241


Type of Document Master's Thesis
Author Umberger, Pierce David
URN etd-06142010-095241
Title Characterization and Response of Thermoplastic Composites and Constituents
Degree Master of Science
Department Engineering Science and Mechanics
Advisory Committee
Advisor Name Title
Case, Scott W. Committee Chair
Batra, Romesh C. Committee Member
Hyer, Michael W. Committee Member
Keywords
  • UHMWPE
  • Time-temperature superposition
  • composite materials
Date of Defense 2010-06-01
Availability unrestricted
Abstract
The research presented herein is an effort to support computational modeling of ultra-high molecular weight polyethylene (UHMWPE) composites. An effort is made to characterize the composites and their constituents. UHMWPE, as a polymer, is time and temperature dependent. Using time-temperature superposition (tTSP), the constituent properties are studied as a function of strain rate. Properties that are believed to be significant are fiber tensile properties as a function of strain rate, as well as the through-thickness shear behavior of composite laminates. Obtaining fiber properties proved to be a challenge. The high strength and low surface energy of the fibers makes gripping specimens difficult. Several different methods of fixturing and gripping are investigated, eventually leading to a combination of friction and adhesion approaches where a fiber was wrapped on an adhesive coated cardboard mandrel and then gripped in the test fixture. Fiber strength is estimated using tTSP to equivalent strain rates approaching 10^6 sec^-1. Punch-shear testing of UHMWPE laminates is conducted at quasi-static strain rates and the dependence of the results on thickness and test geometry is investigated.
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