Accession Number : ADA176133

Title :   A Two-Dimensional Linear Elastic Crack Tip Element for Nastran

Descriptive Note : Interim technical rept. Mar-May 85,

Corporate Author : AEROSPACE STRUCTURES INFORMATION AND ANALYSIS CENTER WRIGHT-PATTERSON AFB OH

Personal Author(s) : Woytowitz, Peter J. ; Citerley, Richard L.

PDF Url : ADA176133

Report Date : JUL 1986

Pagination or Media Count : 60

Abstract : Linear elastic fracture mechanics has gained a substantial acceptance in industry and has become one of the most important design considerations. Many engineering structures such as airplanes, turbines, piping (pressure vessels), bridges, etc. contain pre-existing flaws. As a result of even rather moderate service loads, crack propagation resulting from these flaws can have a dramatic effect on the service life of the component. To account for this reduction in service life, fracture mechanics analysis in conjunction with a fracture control plan is generally implemented. A new crack element has been developed and incorporated into COSMIC/NASTRAN. The element is considered linear, isotropic, and homogeneous. Mode I and II stress intensity factors are automatically calculated. Comparisons to theoretical plane strain solutions for several geometries are presented and demonstrate the accuracy of the developed element. Extensions of the element to three dimensions, anisotropic material, and plastic analysis are discussed. Keywords: Singular Finite Elements.

Descriptors :   *FRACTURE(MECHANICS), *CRACK PROPAGATION, AIRCRAFT, LIFE EXPECTANCY(SERVICE LIFE), STRESS ANALYSIS, MATERIALS, FINITE ELEMENT ANALYSIS, CRACKS, STRUCTURES, ELASTIC PROPERTIES, ACCURACY, STRAIN(MECHANICS), DEFECTS(MATERIALS), SOLUTIONS(GENERAL), ENGINEERING, PLANNING, ANISOTROPY, LINEARITY, PRESSURE VESSELS, PLASTIC PROPERTIES, BRIDGES, STRESS CONCENTRATION, CONTROL, INDUSTRIES

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE