Nonlinear Spectroscopy of Rock and Ceramic Samples

abstrakt

angličtina

This paper describes analysis, principles and apparatus for nonlinear ultrasonic spectroscopy of rock and ceramic samples and also discusses their limitations. The nonlinear ultrasonic testing method was used to detect wave velocity and wave spectra of cylindrical rock sample with heating system in the axis hollow. For this experiment high-temperature ultrasonic sensor with cylindrical contact area was created. This sensor was able to detect an ultrasonic wave up to temperature 230 C. High-temperature gradient appear in the sample, between axis and sample surface. Measuring war performed for sandstone and limestone samples. Dimensions of samples were: diameter 30 mm, height 60 mm. Heating spiral was located into axis of sample where was created cylindrical opening. The six ultrasound sensors were placed on area sample. Sensors enable monitoring of illuminate sample in temporal intervals and six fold canal registration of rise acoustic emission as well. Both type samples were heated in two different velocity of increasing temperature. Slowly warming up was 1 C/min and rapid warming up was 10 C/min. Ultrasonic signal of heated rock sample was analyzed at room temperature before and after warming-up. Exactly first, third and fifth harmonic signal components of response were investigated. After warming-up process amplitude of third and fifth harmonic components was higher considering base harmonic signal.

nonlinear, ultrasonic, spectroscopy, rock, ceramic, heating system

Š. Hefner, T. Lokajíček and J. Šikula

1. 1. 2005

1213-3825

NDT Welding Bulletin

15

2/2005

Česká republika

15

15

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