Development and Application of a Photoelasto-Plastic Method to Study Stress Distributions in Vicinity of a Simulated Crack.
Abstract
The photoelasto-plastic method utilizes the creep and 'frozen' stress characteristics exhibited by epoxy resins and other polymer materials when subjected to a thermal cycle whose maximum temperature is significantly less than the 'critical' temperature of the material. The resulting "frozen" stress-strain behavior is characterized by the generation of nonlinear effective stress-strain curves. Effective stress-strain curves of this nature were generated for two polymer materials, an epoxy and a polycarbonate for various thermal cycles in order to arrive at a material and associated thermal cycle which could be used to simulate the stress-strain behavior of an aluminum alloy. Also the associated birefringence was determined (calibration). Stress-strain similarity was established by use of the Ramberg-Osgood method of stress-strain representation. Upon selection of an appropriate model material and thermal cycle, elasto-plastic stress distributions were determined for infinite plates with centrally located holes to verify the usefulness of the method. This photoelasto-plastic method of stress analysis was then applied to study stress distributions in the vicinity of a simulated crack.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1966
- Accession Number
- ADA307039
Entities
People
- A. R. Hunter
- M. E. Schwarz
Organizations
- Lockheed Martin