Title page for ETD etd-12142009-131241


Type of Document Master's Thesis
Author Stenzler, Joshua Saul
Author's Email Address jstenz@vt.edu
URN etd-12142009-131241
Title Impact Mechanics of PMMA/PC Multi-Laminates with Soft Polymer Interlayers
Degree Master of Science
Department Mechanical Engineering
Advisory Committee
Advisor Name Title
Goulbourne, Nakhiah C. Committee Chair
Dillard, David A. Committee Member
Long, Timothy E. Committee Member
Wicks, Alfred L. Committee Member
Keywords
  • Gas Gun
  • Impact Mechanics
  • Instrumented Impact
  • PMMA
  • Thermoplastic Polyurethane
  • Polyacrylate
  • PC
Date of Defense 2009-11-30
Availability unrestricted
Abstract
The main purpose of this thesis is the systematic, experimental investigation of how a soft interlayer affects the impact response and energy dissipation mechanisms of all-polymer multi-laminates. An instrumented, intermediate impact velocity experimental setup with strain rates on the order of 100 s-1, is used to assess the impact mechanics of three-layered samples consisting of a poly(methyl methacrylate) (PMMA) front, polymer interlayer or adhesive, and polycarbonate (PC) back layer. Instrumentation of the gas gun is achieved with a shock accelerometer measuring contact force and optical displacement sensors recording deflection. Previous impact research utilizing instrumented gas guns by Levy and Goldsmith, and Delfosse et al. have measured contact force, but did not record simultaneous out-of-plane displacement. Signals acquired are temporally aligned allowing for insight into the response of the multi-laminate during impact, which is inaccessible with typical gas guns.

Impact testing is completed on bonded and unbonded sample configurations, with two thermoplastic polyurethane and four polyacrylate interlayers. Quantitative metrics from force and displacement signals, along with post-impact damage observations, are used to compare impact performance between configurations and impact velocities (12 and 22 m/s). In general, the presence and bonding of an interlayer increases impact resistance by mitigating and localizing the impact load. The interlayers are characterized at various strain rates in tension, compression, and shear adhesion. In tension, all interlayers display rate dependence, non-linearity, and hysteretic behavior showing varying degrees of increasing energy dissipation with strain rate. Several trends between sample fracture and energy absorption mechanisms, quasi-static and low rate interlayer response, and metric results are established and discussed.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Stenzler_JS_T_2009.pdf 7.11 Mb 00:32:55 00:16:55 00:14:48 00:07:24 00:00:37

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.