A differential-path ultrasonic technique is used to obtain the acoustic wave propagation characteristics of a mixture of alumina (Al2O3) particles and epoxy (Epon 828-Z). Longitudinal and shear acoustic data are ob tained over a frequency range of 0.5 to 2 MHz and a temperature range of —61°C to 75°C. The longitudinal, shear, and Poisson's ratio master-curve material functions are derived from these data using techniques that were developed for homogeneous isotropic polymers. These functions constitute a complete material description for the mixture in the time (frequency) and temperature range where viscoelastic dispersion is the dominant disper sion mechanism in the composite.
Get full access to this article
View all access options for this article.
References
1.
J.S. Whittier and J.C. Peck, "Experiments on Dispersive Pulse Propagation in Laminated Composites and Comparison with Theory", J. Appl. Mech., Vol. 36 (1969), p. 485.
2.
H.J. Sutherland and R. Lingle, "Geometric Dispersion of Acoustic Waves by a Fibrous Composite", J. Comp. Mat., Vol. 6 (1972), p. 490.
3.
A. Bedford, D.S. Drumheller and H.J. Sutherland , "On Modeling the Dynamics of Composite Materials", Mechanics Today, S. Nemat-Nasser (ed.), Vol. III (1976), p. 1.
4.
S.C. Hunter, "Viscoelastic Waves", Progress In Solid Mechanics, I. N. Sneddon and R. Hill (eds.) Vol. I (1960), p. 3.
5.
H. Kolsky, "Experimental Studies of the Mechanical Behavior of Linear Viscoelastic Solids", Proceedings of The Fourth Symposium on Naval Structural Mechanics, A. C. Eringen , et al (eds.), (1966), p. 357.
6.
H.J. Sutherland , "Dispersion of Acoustic Waves by Fiber Reinforced Viscoelastic Materials", J. Acoust. Soc. Am., Vol. 57 (1975), p. 870.
7.
H.J. Sutherland , "On the Separation of Geometric and Viscoelastic Dispersion In Composite Materials", Int. J. of S. and Struct. , Vol. II (1975), p. 233.
8.
H.J. Sutherland , "Acoustical Determination of the Shear Relaxation Functions for Polymethyl Methacrylate and Epon 828-Z", J. Appl. Phys. (in press).
9.
D.E. Munson , R.R. Boade and K.W. Schuler, "Stress Wave Propagation in Al2O3-Epoxy Mixtures", J. Appl. Phys. (in press).
10.
R. Truel, C. Elbaum and B. Chick, Ultrasonic Methods in Solid State Physics (Academic, 1966).
11.
B.D. Coleman and W. Noll, "Foundations of Linear Viscoelasticity", Rev. Mod. Phys., Vol. 33 (1961) p. 239; Erratum Ibid , Vol. 36 (1964) p. 1103.
12.
J.W. Nunziato and H.J. Sutherland, "Acoustical Determination of Stress Relaxation Functions for Polymers", J. Appl. Phys., Vol. 44 (1973) p. 184.
13.
J.D. Ferry, Viscoelastic Properties of Polymers (Wiley, 1961).
14.
H.J. Sutherland and R. Lingle, "An Acoustic Characterization of Polymethyl Methacrylate and Three Epoxy Formulations", J. Appl. Phys. , Vol. 43 (1972), p. 4022.
15.
R.A. Shapery, "Approximate Methods of Transform Inversion for Viscoelastic Stress Analysis", Proceedings of the Fourth U. S. National Congress of Applied Mechanics, R. M. Rosenberg (ed.), (1962), p. 1075.
