2009 Volume 35 Issue 1 Pages 55-60
At present, various kinds of measures have been taken to solve the environmental problems. Among those measures there is a measure that the environment is evaluated by the sounds. In this paper we paid attention to a character that the sound travels well by way of any material and utilized the sound to measure stress.
The effects of stress and temperature on ultrasonic velocities are studied experimentally in order to establish the acousto-elastic law applicable to thermo-elastic stress analysis. A specimen for uniaxial tensile test is prepared and the sing-around method is used to measure the round-trip time of ultrasonic waves incident normal to the specimen. Two kinds of experiments are carried out too. At first, velocities of longitudinal and transverse waves are measured by varying the temperature under several constant uniaxial stresses, and it is confirmed that the velocity change due to temperature depends linearly on stress.Then the velocities of three waves are measured by varying uni-axial stress under several constant temperatures and the velocity change due to stress is shown to be linearly dependent on temperature. From both results,the stress-temperature coefficients of velocities are determined together with the acousto-elastic constants and temperature coefficients of velocities.
From the results, it will be useful method that the measuring residual stresses based on the stress-dependence of velocity change due to temperature.
