Accession Number : ADP005001

Title :   Methods for Energy Release Rate Calculation,

Corporate Author : MORTON THIOKOL INC BRIGHAM CITY UT WASATCH DIV

Personal Author(s) : Anderson,G. P. ; Abrahamson,L. P.

Report Date : NOV 1984

Pagination or Media Count : 7

Abstract : This paper compares four methods for obtaining fracture mechanics parameters from finite element computer programs. Total energy release rate values are obtained using numerical differentiation, crack closure integral, modified crack closure integral, and crack opening displacements. A commonly used method, numerical differentiation of strain energy, does not yield the correct energy release rate when displacement and traction loads are applied simultaneously. The authors found that the relatively new crack closure integral method was preferable. Several test problems showed that, when properly applied, results from numerical differentiation and crack closure integral techniques were within 0.1% agreement. (Author)

Descriptors :   *FRACTURE(MECHANICS), *COMPUTER PROGRAMS, *FINITE ELEMENT ANALYSIS, *NUMERICAL METHODS AND PROCEDURES, CRACKS, CRACK PROPAGATION, INTEGRALS, ENERGY TRANSFER, RATES, STRAIN(MECHANICS), DISPLACEMENT, THERMAL STRESSES, SOLID ROCKET PROPELLANTS, PROPELLANT GRAINS, VISCOELASTICITY, SYMPOSIA

Distribution Statement : APPROVED FOR PUBLIC RELEASE