Determination of elastic constants of a concrete specimen using transient elastic waves

Abstract

This paper presents the results of measuring the Rayleigh wave as well as longitudinal wave velocities in a concrete specimen using transient elastic waves. The Rayleigh surface wave generated by a steel ball impact on a concrete material is studied in detail and then a method for the determination of Rayleigh surface wave velocity based on the cross-correlation method is proposed. The longitudinal wave velocity of a concrete specimen is determined by measuring the wavefront arrival of a longitudinal wave. A special triggering device for the accurate determination of the impact time origin is utilized. The measured velocities of both the Rayleigh wave and the longitudinal wave in the concrete specimen are in good agreement with those measured by utilizing the conventional ultrasonic method. It is noted that with the Rayleigh wave and the longitudinal wave velocities measured, the Young’s modulus as well as the shear modulus of a concrete specimen can be obtained in a straightforward way.

Rayleigh wave velocity computation using principal wavelet-component analysis

“…Fig. 5 schematically shows the TOF determination using two conventional methods (peak-to-peak [5] and cross-correlation [6]) in addition to the proposed technique. In special, Fig.…”

“…Therefore, the proposed technique had expected to give the exact R-wave velocity. Considering the general experimental setup for measurement [4][5][6][7][8], as shown in Fig. 2, the axissymmetric model was designed as shown in Fig.…”

“…The peak-to-peak method is a heuristic method in the time domain, and it determines the timeof-flight (TOF) with the arrival time of the peak amplitude in the measured waveforms [5]. The cross-correlation technique determines the TOF by calculating the time when the maximum correlation between the two waveforms appears [6]. However, the peak amplitude and the cross-correlation in the time domain are easily interfered by scattered and reflected body waves.…”

Measurements of dynamic properties of concrete structures using flexural wave propagation characteristics

“…Direct P-wave speed measurements were performed (ASTM C1383-04, 2004) utilizing the characteristic that the P-wave speed is the fastest type of stress wave. In order to test large specimens other than thin slab concrete, Rayleigh surface wave velocity measurements using the cross correlation function were proposed by Wu et al (1995). This method is limited to large specimens, since long distances between the source and receiver are required.…”

Poisson's ratio from polarization of acoustic zero-group velocity Lamb mode

“…9 To determine the thickness and/or mechanical properties, the frequency of the S1-ZGV mode must be complemented with two additional parameters, e.g., transverse wave speed and Poisson's ratio. 10 Combined impact-echo and surface wave measurements, 11 where Poisson's ratio typically is determined from the longitudinal wave and the Rayleigh wave velocity, 12 can be used to obtain these two additional parameters. However, systematic errors from near-field effects and velocity variation through the thickness can lead to an uncertain estimation of Poisson's ratio.…”