Fracture Prediction in Plane Elasto-Plastic Problems by the Finite Element Method.
Abstract
A finite element program based on the plane stress assumption is developed and applied to elasto-plastic fracture problems involving monotonically increasing loads. The program directly predicts the initiation and propagation of fracture in the structure. That is, the concept of stress intensity factor is not utilized in the present approach. The approach uses a piecewise linear approximation of the actual stress-strain curve for the material, and the maximum strain criteria to predict both the yield and fracture. An incremental loading technique is employed to load the structure, and a zero modulus-unload reload scheme is developed to handle the response of the structure at fracture. Comparisons with published data on a cracked panel, and the experimental data obtained during this study on tensile and cracked specimens show that this finite element program can accurately predict load and deflection at fracture, load-deflection curves, fracture initiation locations, and stable or unstable crack propagation. This approach is shown to be highly dependent on the mesh density in areas of high strain gradients.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1978
- Accession Number
- ADA105500
Entities
People
- Robert Gary Belie
Organizations
- Air Force Institute of Technology