Ultrasonic Velocity Studies of Composite and Heterogeneous Materials
Ultrasonic measurements of wave-propagation characteristics in composite and heterogeneous materials provide an excellent means to study their mechanical properties. In recent years we have studied, both theoretically and experimentally, characteristics of elastic-wave propagation in particlereinforced composites and heterogeneous materials as well as in homogeneous and laminated fiber-reinforced composites. Comparison of theoretical predictions with obervations of wave velocities has shown good agreement and has provided a way to evaluate microstructural dependence of mechanical properties of these materials. Modeling predictions coupled with observations can also be used to obtain mechanical properties of the reinforcing phase, which are sometimes not easily obtained. In this paper we present results of some of these recent studies.
We also present results of our study of changes in phase velocities and attenuation caused by interface layers between the reinforcing phase and the matrix. We show that this third phase measurably modifies the dispersion behavior. This should lead to effective characterization of interface layer properties by ultrasonic methods.
KeywordsElastic Constant Phase Velocity Cast Iron Elastic Wave Interface Layer
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- 12.S. K. Datta and H. M. Ledbetter, Anisotropic Elastic Constants of a Fiber-reinforced Boron-Aluminum Composite, in: “Mechanics of Nondestructive Testing,” W. W. Stinchcomb, ed., Plenum, New York (1980).Google Scholar
- 14.H. M. Ledbetter, Dynamic Elastic Modulus and Internal Friction in Fibrous Composites, in: “Nonmetallic Materials and Composites at Low Temperatures,” Plenum, New York (1979).Google Scholar
- 16.S. K. Datta, Diffraction of Plane Elastic Waves by Ellipsoidal Inclusions, JASA 61:1432.Google Scholar
- 18.S. K. Datta and H. M. Ledbetter, Effect of Interface Properties on Wave Progagation in a Medium with Inclusions, in: “Mechanics of Material Interfaces,” A.P.S. Selvadurai and G.Z. Voyiadjis, eds., Elsevier, The Netherlands. (1986).Google Scholar
- 23.S. K. Datta, A. H. Shah, R. L. Bratton, and Y. N. Al-Nassar, Guided Wave Propagation in Laminated Composite Plates with Low-Velocity Interface Layers, to be published.Google Scholar
- 24.T. Okamoto, A. Kagawa, K. Kiyoshi, and H. Matsumoto, Effects of Graphite Shape on Thermal Conductivity, Electrical Resistivity, Damping Capacity and Young’s Modulus of Cast Iron below 500 degrees C” J of the Japan Foundrymen’s Soc 55:32 (1983).Google Scholar
- 25.D. Lohe, O. Vohringer, and E. Macherauch, Der Einfluss der Graphitform auf den Elastizitatsmodul von ferritischen GusseisenWerkstoffen, Zeitschrift fur Metallkunde 74:265 (1983).Google Scholar
- 28.E. Kroner, and H. Koch, Effective Properties of Disordered Materials, SM Archives 1:183 (1976).Google Scholar
- 29.H. Wawra, B. K. D. Gairola, and E. Kroner, Comparison between Experimental Values and Theoretical Bounds for the Elastic Constants E, G, K and µ of Aggregrates of Noncubic Crystallites, Zeitschrift fur Metallkunde 73:69 (1982).Google Scholar