Measurement of the elastic constants by ultrasonic pulse-echo method in anisotropic materials
This procedure tries to simulate the elastic properties of materials based on measurements in preferred wave propagation directions. Test specimens were used to measure propagation velocity in different axes by the ultrasonic method in the pulse-echo technique. Measurements made by ultrasound made it possible to measure the tensile components of elastic constants with significant variations according to the composition of the materials. The results of the measurements were compared with the values obtained by other authors in similar materials. The elastic constants were obtained through their association with the propagation velocity relations in different directions in the study material. The results shows the values of the measured elastic constants [GPa] by means of the ultrasonic velocity measurement test whose values for each direction for the different materials tested.
Steps to reproduce
The measurement of velocity in different propagation axes implies in time changes of the order of nanoseconds. These changes can be determined by measuring the delay between the ultrasonic wave echoes. To obtain the wave time variations along the thickness of the material a pulse-echo configuration was used, where a single transducer is used as the emitter / receiver. The acquired signal corresponds to a succession of echoes from the opposite face to which the transducer is coupled. The wave travel time is the time measured between two consecutive echoes. The transducers used were of longitudinal and transverse waves with normal incidence and frequency of 5MHz and 2.25MHz, respectively, of Panametrics 11mm in diameter; a Matec SR9000 pulse generator associated with a Tektronic 2221A 100MHz oscilloscope, and a Stanford DG53 pulse delay.