Notes on the experimental measurement of fracture toughness of shape memory alloys
Abstract
A mechanics-aided test method for measuring the fracture toughness of shape memory alloys, the deformation/failure response of which violates basic assumptions of ASTM standards for measuring fracture toughness in conventional ductile materials, has been recently proposed. The proposed methodology relies on the resistance curve format of ASTM standards, but differs from it in the determination of the elastic part of the J value, for both stationary and advancing cracks, in an effort to accommodate the transformation/orientation-induced changes in the apparent elastic properties. This article discusses the proposed modifications to ASTM standards, that is, the expected degree of improvement in the measurement accuracy, the need for further ones regarding the uncertainty as to where to specify the fracture point on the obtained resistance curve, the specimen thickness requirement to ensure a conservative, constraint-independent measurement, and the temperature dependence of the measurements.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 09, 2019
- Source ID
- 10.1177/1045389x19888730
Entities
People
- Jasdeep Makkar
- Theocharis Baxevanis
Organizations
- Air Force Office of Scientific Research
- National Aeronautics and Space Administration
- University of Houston