Papers by Keyword: Rayleigh Waves

Abstract: The investigations of ultrasound Rayleigh wave parameters changing depending on localized plastic strain in AlCu4MgSi alloy and austenitic stainless steel AISI 304 are presented in this paper. Measurements of the ultrasound parameters and localized strain bands motion were carried out in-situ during the tensile tests of the specimens at the constant rate and room temperature. It has been found that the measurement of ultrasound velocity allows detecting the initiation of a localized strain band and its location relative to the acoustic measurement area independently of the deformation mechanism.

Abstract: A new method for non-destructive evaluation of the mechanical properties of structural materials has been developed. This is based on measurements of the ultrasound propagation velocity in deforming materials. Preliminarily investigations were carried out in order to relate the ultrasound propagation velocity to the mechanical characteristics of the deforming material. A detailed description of suitable devices intended for ultrasound propagation velocity measurement with high accuracy is presented. Using Zr-based alloys as an example, it is shown that the method can be used for the monitoring of zirconium billets from which nuclear reactor fuel cladding is fabricated by cold rolling.

Abstract: The hoop orientation degree of PVC-O pipes is an important factor to the evaluation of forming quality. In this paper, according to the propagation characteristic, Rayleigh wave was utilized to explore the orientation degree of the PVC-O pipes. The Rayleigh wave test is consistent with the longitudinal wave test in charactering the orientation degree of the pipes. The results shows that Rayleigh wave is very sensitive to orientation structure, and it is feasible to be used in the hoop orientation detection of the PVC-O pipes. Due to the simple manner of the detection, the method mentioned in this paper provided the possibility of on-line detection for the orientation of PVC-O pipes.

Abstract: It has been proved by the seismologic observation of 5.12 Wenchuan Earthquake that a large number of shallow-buried depth mountain tunnels at the portal are underwent severe damage. Earthquake waves, especially Rayleigh waves may be a major factor causing the damage. The numerical model of the shallow-buried depth mountain tunnels by FLAC3D is establishes in this paper, and the dynamic responses of the shallow-buried depth mountain tunnels under the action of Rayleigh waves are simulated by loading on normal Rayleigh waves. The effect of different strength of surface waves is simulated by the in-site blasting tests. The dynamic responses of the tunnel lining under the action of Rayleigh waves are obtained by filtering and composition separation in order to discuss the incidence and mechanism of action. The results show that the dynamic responses of tunnel lining under the action of Rayleigh waves mainly focuses on the portal of tunnel, namely the buried depth and lengthways depth of the tunnel are 0~16m and 0~20m, the tunnel lining is damaged easily in the incidence, and the multiplicative effect of Rayleigh waves often occurs at the portal; beyond the incidence, Rayleigh waves attenuate rapidly and the dynamic responses of the tunnel lining decreases gradually, which has little effects on the safety of tunnel structures.