| METADEX Antwortnummer 27 - © 1998 CSA |
| Title |
| | Acoustoelastic Measurements Pertaining to the Nondestructive Characterization of Residual Stress in a Heat-Treated Steel Railroad Wheel. |
| Author |
| | Clark, A.V.; Fukuoka, H.; Mitrakovic, D.V.; Moulder, J.C. |
| Organization |
| | NIST; Osaka University; University of Belgrade; Iowa State University |
| Publication Source |
| | Mater. Eval. (July 1989) 47, (7), 835-841
ISSN: 0025-5327 |
| Document Type |
| | Journal |
| Language |
| | English |
| Abstract |
| | The state of residual stress in the rim of a heat-treated steel railroad wheel has been characterized using the acoustoelastic effect. Shear-horizontal (SH) waves were propagated through the rim thickness by transducers operating in pulse-echo-mode. The difference in arrival times of orthogonally polarized SH-waves (acoustic birefringence) was measured with a precision of plus/minus 1 ns or better. This difference is related to the state of stress and texture in the rim. Measurements were made using two transducers: a piezoelectric device made of lead zirconate titanate (PZT), and an electromagnetic-acoustic transducer (EMAT). The PZT device had been used to measure residual stresses in rolled-steel wheels and was used as a reference against which EMAT measurements were compared. Measurements made as a function of radial position on the rim indicated a gradient of stress (assuming constant texture). The stress gradient measured by the EMAT was in good agreement with that measured by the PZT transducer. Measurements made around the circumference of the rim indicated an axisymmetric state of stress and texture for regions closest to the tread, with increasing departure from axial symmetry as the inner edge of the rim was approached. The EMAT and PZT measurements both indicated this trend. The effect of surface preparation on EMAT measurements was characterized. The difference in birefringence between measurements made on rough surfaces and those made on prepared smooth surfaces was usually less than 2 x 10-4, which gives an (approximate) difference in stress of 25 MPa. The good agreement between EMAT and PZT values of birefringence, plus the relative insensitivity of the EMAT to surface preparation, indicate that EMATs are quite suitable for field measurements of residual stress. . 14 ref.-AA |
| Accession Number |
| | 90(2):22-202 |
