AN EVALUATION OF 3 METHODS TO MEASURE THE DYNAMIC ELASTIC-MODULUS OF STEEL

The dynamic elastic modulus of 1018 steel was measured with three different instruments: the Grindo-Sonic, the Modul-R, and the piezoelectric ultrasonic composite oscillator technique (PUCOT). In total, 276 tests were made. The overall mean elastic modulus for all the specimens and all three methods was 207.1 GPa with a standard deviation of 2.75 GPa (1.33%). The mean values of elastic modulus and standard deviation measured by the Grindo-Sonic, the Modul-R, and the PUCOT were 208.1 and 0.86 GPa (0.41%), 205.8 and 3.40 GPa (1.65%), and 207.9 and 2.80 GPa (1.35%), respectively. The means of the elastic modulus for the PUCOT, Grindo-Sonic, and Modul-R methods fell within 0.39%, 0.48%, and 0.63%, respectively, of the overall mean elastic modulus of 207.1 GPa. All three instruments yielded comparable values of elastic modulus and comparable standard deviations. However, the Grindo-Sonic and Modul-R instruments were quicker for use than the PUCOT, but the PUCOT was more forgiving on the specimen geometry than the other two instruments.