Evolution of spall-damage in iron caused by repeated plate impacts: Ultrasonic evaluation
| Autor: | K. Fujimoto, Toshihiro Ito, Naoya Nishimura, Y. Ogi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Acoustics and Ultrasonics business.industry Attenuation Acoustics 020101 civil engineering 02 engineering and technology Spall Amplitude ratio Frequency spectrum 0201 civil engineering Intensity (physics) Stress (mechanics) 020303 mechanical engineering & transports 0203 mechanical engineering Nondestructive testing Ultrasonic sensor business |
| Zdroj: | Ultrasonics. 83:88-93 |
| ISSN: | 0041-624X |
| Popis: | This paper focuses on the developed of spall-damage that occurs in pure iron as a result of repeated impact. The employed low-frequency scanning acoustic microscopy (LF-SAM) observations combined with the measurements of ultrasonic wave velocity, attenuation, backscattering intensity and amplitude spectrum of the reflected wave, enabled us to provide a nondestructive evaluation. The spall-damage distribution was analyzed in the C-scan images, and we found the spall-damage increase with impact stress when the latter exceeds the characteristic spall-threshold stress. Moreover, we recorded the decreased sound velocity, amplitude ratio, and the increase of backscattering intensity, significant attenuation (the high frequency component of the reflected wave) for enhanced impact stress. It was also demonstrated that the tiny cracks generated in iron develop significantly during subsequent impacts either with lower or higher impact stress. Since the presented results concern for the first time the multiple-impact experiments, we contend that the applied ultrasonic investigations constitute the effective method of nondestructive spall-damage evaluation. |
| Databáze: | OpenAIRE |
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