Accession Number : AD0775041

Title :   Evaluation of the Fracture Postulate for Viscoelastic Materials.

Descriptive Note : Master's thesis,


Personal Author(s) : Kapernick,Robert Edwin

Report Date : DEC 1973

Pagination or Media Count : 41

Abstract : Experimental studies were conducted on unfilled viscoelastic materials such as a carboxy terminated polybutadiene to evaluate the fracture postulate which states that crack velocity is a unique function of stress intensity factor. To do this, fracture characterization tests were conducted for constant load, constant displacement, and constant displacement rate histories. A cyclic study, a more sophisticated application of the constant displacement rate case, was also conducted as a further evaluation of the fracture postulate. The analytical theory used in obtaining viscoelastic stress intensity factors was based upon linear theory and sharp crack geometries. Moderate correlation was obtained among all test cases, notwithstanding the presence of significant specimen strains and finite crack tip radii. (Author)

Descriptors :   *Fracture(Mechanics), *Solid rocket propellants, *Polymers, Viscoelasticity, Crack propagation, Stresses, Theses

Subject Categories : Plastics
      Solid Rocket Propellants

Distribution Statement : APPROVED FOR PUBLIC RELEASE