Abstract

In the RHI the Resonant Frequency method is used for Elastic Material Properties determination at refractory samples with different geometrically scales. When the Resonant Frequency Method is used as a pre-testing tool for Round Robin Tests many samples with different geometries must be tested. First of all the sample scale is large at Refractory bricks, after shaping the geometry size is small at laboratory samples. The Young’s Modulus determination by the Resonant frequency method described, e.g. in ASTM C1259-08 is time and money consuming. Because the measurement and analysis procedure contains many steps. This time must be multiplied by the number of samples and necessary measurement repetitions. Therefore, a way was searched to reduce the time demand at the Resonant Frequency based Young’s Modulus determination. A solution was found. It is based on the analysis of the frequency spectrum of all vibration modes of a specimen. The vibration modes are excited by the standardized impulse hammer and direction. The alternative Young’s Modulus determination method uses the principle of free vibration of all wave types and orders in a specimen geometry. By a software the Young’s Modulus values of all significant frequency peaks of all measured spectra are computed. A search algorithm determines the plausibility of the Young’s Modulus of each resonant frequency combination of all wave types and orders. If a plausible Young’s Modulus combination was found, the result is given out by the search algorithm. This alternative resonant frequency Young’s Modulus determination method was verified by several ways. It was done at different sample geometries and Refractory material types. For a methodical verification the Standard Resonant Frequency method according to ASTM C1259-08 and the Ultrasonic transmission method are used to determine the Young’s Modulus values. For a theoretical verification the Finite Element Eigenfrequency calculation was applied at different geometries and material properties. At the Eigenfrequency data the alternative Young’s Modulus was applied and the results compared with the Finite Element Simulation parameters of the data set. The Finite Element Simulation was done by the Simulation Department of the RHI. The verification was successfully finished. The described alternative Young’s Modulus determination Method can be automatized and computes the Young’s Modulus values of all available wave types and frequency orders of a spectrum in a split second. By this alternative procedure a significant time reduction of the Young’s Modulus computation procedure is possible. In future this method can also used to determine the poisons ratio automatically.