Dynamic Photoelasticity as an Aid to Sizing Surface Cracks by Frequency Analysis
This paper describes a method for sizing surface cracks that have been modeled as machined slots.1 Several techniques have been used in the past to size surface cracks. Most use compressional (P) and shear (S) waves. Less attention has been given to using Rayleigh (R) waves or surface waves for sizing cracks. Since the energy of Rayleigh waves is confined to a layer of material near the surface, these waves have à great potential for sizing surface cracks. These are exactly the cracks that are hardest to characterize with traditional ultrasonic techniques because they lie in the “near-field” region of the transducers.
KeywordsShear Wave Rayleigh Wave Nondestructive Test Acoustic Surface Wave Transmitted Wave
Unable to display preview. Download preview PDF.
- 1.A. Singh, “Crack Depth Determination by Ultrasonic Frequency Analysis Aided by Dynamic Photoelasticity,” M.S. Thesis, Iowa State University, Ames, Iowa (1980).Google Scholar
- 2.H. W. Reinhardt and J. W. Dally, Some Characteristics of Rayleigh Wave Interaction with Surface Flaws, Materials Evaluation 28:213–220 (1970).Google Scholar
- 6.M. G. Silk, Sizing Crack-like Defects by Ultrasonic Means, in: “Research Techniques in Non-Destructive Testing,” R. S. Sharpe, ed., Academic Press, London (1977).Google Scholar
- 7.L. L. Morgon, The Spectroscopic Determination of Surface Topography using Acoustic Surface Waves, Acustica 30:222–228 (1974).Google Scholar
- 8.L. J. Bond, “Finite Difference Methods Applied to Ultrasonic Non-destructive Testing,” Proc. of the meeting on ARPA/AFML Review of Progress in Quantitative NDE, La Jolla, CA, July 1979 (To be published).Google Scholar
- 9.J. D. Achenbach, “Wave Propagation in Elastic Solids,” North-Holland Publishing Company, Amsterdam (1973).Google Scholar
- 12.M. J. Forrestal, L. E. Fugelso, G. L. Meidhardt and R. A. Felder, “Response of a Half Space to Transient Loads,” Proc. of Engineering Mechanics Division Speciality Conference ASCE (1966).Google Scholar