Accession Number : ADA311377

Title :   A Continuum Model for Viscoelasticity, Damage, and Permanent Deformation with Application to Swirl-Mat Polymeric Composites.

Descriptive Note : Technical rept.,

Corporate Author : TENNESSEE UNIV KNOXVILLE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING

Personal Author(s) : Abdel-Tawab, K. ; Weitsman, Y.

PDF Url : ADA311377

Report Date : 12 JUL 1996

Pagination or Media Count : 39

Abstract : A comprehensive thermodynamic framework is proposed for modeling the behavior of polymeric composites exhibiting viscoelasticity, damage and permanent deformation. In the present formulation, the total strain is decomposed into viscoelastic and permanent components. The effect of damage on the constitutive behavior is introduced through direct coupling between damage and the internal state variables representing deformation of the undamaged (virgin) material. This approach accounts for time-dependent damage as well as damage-induced changes in material symmetry. The viscoelastic part of the proposed constitutive model is first formulated for a general case of damage coupled with nonlinear viscoelasticity, and subsequently specialized to coupling with linear viscoelasticity. Permanent deformations are discussed in view of recent experimental findings. Finally, the proposed constitutive model is applied to experimental data for swirl-mat polymeric composites.

Descriptors :   *DAMAGE, *POLYMERS, *COMPOSITE MATERIALS, *DEFORMATION, *VISCOELASTICITY, COUPLING(INTERACTION), LINEAR SYSTEMS, EXPERIMENTAL DATA, TIME DEPENDENCE, MODELS, THERMODYNAMICS, STRAIN(MECHANICS), NONLINEAR SYSTEMS, INTERNAL, SYMMETRY.

Subject Categories : Polymer Chemistry
      Laminates and Composite Materials
      Fluid Mechanics
      Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE