Three Dimensional Effects Near a Crack Tip in a Ductile Three Point Bend Specimen. Part 2. An Experimental Investigation Using Interferometry and Caustics
Abstract
An experimental investigation is undertaken to assess three- dimensional effects near a crack front in a ductile three-point bend specimen. The possibility of using the optical method of caustics for the measurement of the J integral in the presence of large scale yielding and three dimensional fields is also investigated. Experiments using the optical methods of caustics by reflection and Twyman-Green interferometry are performed simultaneously on either side of the test specimen. The load and load-point displacement are also measured. The experimental results are compared with very good agreement to the results of a finite element simulation of the experiment. The caustics experiments are used to obtain a calibration relation between the value of the J integral and the caustic diameter for load levels up to fracture initiation. It is proposed that such a calibration be used in dynamic fracture initiation experiments for the measurement of the time history of the dynamic J -integral.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1988
- Accession Number
- ADA202637
Entities
People
- Alan T. Zehnder
- Ares J. Rosakis
Organizations
- California Institute of Technology