Accession Number : ADA303087

Title :   Strain Energy Release Rate Determination of Stress Intensity Factors by Finite Element Methods.

Descriptive Note : Master's thesis,

Corporate Author : DELAWARE UNIV NEWARK CENTER FOR COMPOSITE MATERIALS

Personal Author(s) : Walsh, Richard M., Jr

PDF Url : ADA303087

Report Date : DEC 1982

Pagination or Media Count : 134

Abstract : The determination of the Mode I stress intensity factors for selected crack configurations, using finite element methods and energy release rate principles, is the subject of this study. The crack configurations which were investigated were the double edge crack, the single edge crack, and the center crack. The method of analysis utilized was the Stiffness Derivative Method (7). This approach relates the change in strain energy resulting from crack advancement, to the change in the stiffness matrix of the structure containing the crack. The results indicated that through mesh optimization and proper control of certain parameters including the crack advance increment, the crack tip element contour size, and mesh refinement, an accurate solution can be calculated with a relatively coarse finite element mesh consisting entirely of contemporary elements. The numerically generated solutions are compared with analytical solutions with the results within 0.001 percent of each other for the double edge crack, 0.858 percent for the single edge crack, and 2.021 percent for the center crack.

Descriptors :   *STRESS STRAIN RELATIONS, *FINITE ELEMENT ANALYSIS, *CRACK PROPAGATION, COMPUTER PROGRAMS, STRESS ANALYSIS, COMPOSITE MATERIALS, DEFORMATION, STIFFNESS, CRACKING(FRACTURING), DISPLACEMENT, ELASTIC PROPERTIES, MODULUS OF ELASTICITY, ACCURACY, THESES, ENERGY TRANSFER, FRACTURE(MECHANICS), MESH, STRAIN RATE, DEFECTS(MATERIALS), HIGH STRENGTH, DESIGN CRITERIA, STRENGTH WEIGHT RATIO, SAFETY FACTOR.

Subject Categories : Mechanics
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE