Acoustic Emission Determination of Deformation Mechanisms Leading to Failure of Naval Alloys. Phase I.
Abstract
The purpose of the present research is to use innovative optical techniques and superior signal capture and processing systems to determine the waveforms, frequency spectra, and propagational behavior of the acoustic emission signals generated by the various mechanical deformation mechanisms leading to failure of metal alloys of prime importance to naval structures. The ultimate goal of this research is to absolutely determine the degree to which precise characterization of the acoustic emission signals can serve to remotely assess the severity of mechanical damage and give early warning of impending failure. Experiments were performed using a modified piezoelectric transducer, a Fizeau type interferometer, and a modified Michelson interferometer. Acoustic emission events were generated by pulling microtensile specimens in an extremely quiet microtensile machine and by the brittle, step unloading fracture of glass capillary tubes on the surface of test specimens possessing different geometries. All acoustic emission event waveforms were recorded by a high speed transient recorder and stored on magnetic mini-diskettes for analysis on a high speed digital computer and for future propagational behavior and waveform analysis. Specimens which were pulled on the microtensile machine were examined under optical and scanning electron microscopes to determine a point by point correlation between acoustic emission events and microstructural changes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1981
- Accession Number
- ADA102762
Entities
People
- J. T. Glass
- R. E. Green Jr.
- S. Majerowicz
Organizations
- Johns Hopkins University