Elastic-Plastic Finite Element Model Comparisons in Fracture Mechanics.
Abstract
Stress near a crack tip in plasticity was analyzed using three different finite element modelings; a constant strain viscoplastic triangle, an eight-noded elastic-plastic quadrilateral and a crack tip elastic-plastic singularity element. The specimen under consideration was a center cracked plate made from IN-100. The half-crack length was 0.1367 in (3.472 mm). An elastic solution was formulated and two different loadings to generate plasticity were considered. Fine mesh and coarse mesh solutions for the higher order elements were generated and compared. Comparisons were made based on an equal number of degrees of freedom in two specific regions referred to as the near field and the far field regions. It was determined that the elements whose elastic solutions conformed best to linear elastic fracture mechanics predictions were the constant strain triangle and the eight-noded quadrilateral in a fine mesh. The crack tip element did not perform as well as was expected. For the plastic analysis, the constant strain triangle exhibited the largest plastic region and gave the most accurate stress profiles.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1981
- Accession Number
- ADA111122
Entities
People
- Howard Dwight Gans
Organizations
- Air Force Institute of Technology