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Time-temperature response of multi-phase viscoelastic solids through numerical analysis

Citation

Brinson, L. C. (1990) Time-temperature response of multi-phase viscoelastic solids through numerical analysis. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-10292003-112909

Abstract

A numerical model has been constructed for the study of the properties of multi-phase viscoelastic composites. The model utilizes the dynamic correspondence principle of viscoelasticity in a finite element program to solve boundary value problems simulating uniaxial tension or simple shear and obtains the global complex Young's or shear moduli of the composite.

Each phase of the composite is considered to be thermorheologically simple. The resulting modulus properties of the composite however, are thermorheologically complex and this investigation examines the nature of time-temperature behavior of multi-phase composite materials. The specific composite considered throughout this study contains viscoelastic inclusions embedded in a different viscoelastic matrix material. The deviation of the composite moduli from thermorheologically simple behavior of the matrix material is shown to occur at frequencies and temperatures where the glass-to-rubber transition of the included phases are reached.

Properties of polystyrene and polybutadiene are used to investigate the thermorheological complexity (non-shiftability) of a Styrene-Butadiene-Styrene (SBS) block copolymer. To achieve congruence of the results with experimental data, it is necessary to consider a transition phase of properties "intermediate" to those of styrene and butadiene. Using accurate physical information on the individual phase properties and on the interphase region, it is possible to utilize the numerical model to predict long term properties of multi-phase composites from short term laboratory data. Lacking detailed information on the properties of a particular phase (e.g., the interphase), but knowing the time dependent properties for the composite material at a broad range of temperatures, it is also possible to use the numerical tool to solve an inverse problem and determine the unknown properties of the phase in question.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:composites; correspondence principle; finite elements; interphase; mechanical properties; multiphase polymer; viscoelasticity
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Applied Mechanics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Knauss, Wolfgang Gustav
Thesis Committee:
  • Knauss, Wolfgang Gustav (chair)
  • Ravichandran, Guruswami
  • Knowles, James K.
  • Hall, John F.
  • Tschoegl, Nicholas W.
Defense Date:2 February 1990
Author Email:cbrinson (AT) northwestern.edu
Record Number:CaltechETD:etd-10292003-112909
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-10292003-112909
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4297
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:30 Oct 2003
Last Modified:26 Dec 2012 03:07

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