Full-Field Stress-Strain Analysis of Cracking Plates.
Abstract
This research seeks to lay the groundwork for experimentally tracking changing gradient fields of stress and strain as damage evolves in a flat edge-cracked plate under uniaxial loading. The task is difficult because at many points there are biaxial stresses that are in-phase, non-proportional, and possibly perturbed by localized plastic strains. Significant progress can be made by employing the new technique of differential infrared thermography (DIT), commonly known as the SPATE method (Stress Pattern Analysis by Thermal Emissions). DIT provides out put that is proportional to the peak-to-peak sum of the elastic stress change (delta(sigma(1) + sigma (2)) on the surface of a cyclically loaded member. Thus it is important to focus first on the resolution of the sigma (x) and sigma (y) distributions of a biaxial field. Study results demonstrate that DIT (using the SPATE method) is effective for investigating complex biaxial stress-strain fields and regions involving large stress-strain gradients. The validity of the SPATE method for elastic deformations of notched specimens has been proven. The SPATE isopachic data have been separated into individual and sigma(Y)distributions using simple procedures. In most cases the error in these analyses is approximately 1 to 3%.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 11, 1986
- Accession Number
- ADA176986
Entities
People
- Bela I. Sandor
- G. D. Farnham
- K. C. Schmid
Organizations
- University of Wisconsin–Madison