Accession Number : AD0772895

Title :   Mechanical Behavior of Viscoelastic Materials.

Descriptive Note : Final rept.,

Corporate Author : ARMY CONSTRUCTION ENGINEERING RESEARCH LAB CHAMPAIGN ILL

Personal Author(s) : Naus,Dan

Report Date : DEC 1973

Pagination or Media Count : 86

Abstract : This investigation was thus conducted to provide a better understanding of viscoelastic material behavior. The behavior of a typical viscoelastic material, PMMA, was evaluated when subjected to various load rates, magnitude of load, or magnitude of strain. The results indicate that the behavior of the visco-elastic material, PMMA, (i.e., tensile creep, stress relaxation, and fracture toughness properties) is dependent on time, stress, and strain. The results also indicate that viscoelastic materials are able to adsorb large amounts of energy, exhibit large tensile strains prior to fracture, exhibit increasing ultimate tensile strength values with increased rates of deformation, relax to relieve stresses resulting from induced displacements, provide resistance to crack propagation. Also, a qualitative fracture model was developed using rheological models in conjunction with a rigid-plastic cracked strip model to describe material behavior near a flaw. The model was related to the tensile and fracture behavior of viscoelastic materials. (Author, modified-PL)

Descriptors :   *Polymers, Mechanical properties, Polymethyl methacrylate, Tensile properties, Creep, Loads(Forces), Fracture(Mechanics), Crack propagation, Structural properties, Deformation

Subject Categories : Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE