In the present investigation high-speed photography along with the well-known method of caustics were used for the determination of the crack-propagation velocity and the K I-stress intensity factor in iron-epoxy particulate composites. Specimens with three different low percentage filler-volume fractions were used; namely, 3%, 5% and 7%. It was found that the mean crack-propagation velocity decreases linearly with increasing filler-volume fraction. In addition, by using the method of caustics, the KI-stress intensity factor was calculated for each one of the composite specimens separately. It was found that the KI-S.I.F. increases by steps with increasing crack-length.
Get full access to this article
View all access options for this article.
References
1.
Papanicolaou, G.C., Paipetis, S.A. and Theocaris , P.S., "The Concept of Boundary Interphase in Composite Mechanics", Colloid and Polymer Science , 256, No. 7, pp. 625-630 (1978).
2.
Papanicolaou, G.C. and Theocaris , P.S., "Thermal Properties and Volume Fraction of the Boundary Interphase in Metal-Filled Epoxies", Colloid and Polymer Science, 237, pp. 625- 630 (1979).
3.
Theocaris, P.S. and Papanicolaou , G.C., "The Effect of the Boundary Interphase on the Thermomechanical Behaviour of Composites Reinforced with Short Fibres ", Fibre Science and Techn., 12, pp. 421-433 (1979).
4.
Theocaris, P.S. and Ioakimidis, N., "The Equations of Caustics for Crack and Other Dynamic Plane Elasticity Problems", Engrg. Fracture Mechanics, 12, No. 4, pp. 613-615 (1979).
5.
Craggs, J.W. , "On the Propagation of a Crack in an Elastic-Brittle Material", Jnl. Mech Phys. Solids8, pp. 66-75 (1960).
6.
Kobayashi, A.S. , Engstrom, W.L. and Simon, B.R., "Crack Opening Displacements and Normal Strains in Centrally Notched Plates", Exp. Mechanics, XXVI, No. 1, pp. 163-170 (1969).
7.
Theocaris, P.S. and Papadopoulos , G.A., "Elastodynamic Forms of Caustics for Running Cracks Under Constant Velocity", Engng. Fracture Mech., 13, No. 4, pp. 683-698 (1980).
8.
Theocaris, P.S. and Gdoutos, E., "An Interferometric Method for the Direct Evaluation of Principal Stresses in Plane-Stress Fields", Jnl. Phys. D: Appl. Phys., 7, pp. 472-482 (1974).
9.
Raftopoulos, D., Karapanos, D. and Theocaris, P.S. "Static and Dynamic Mechanical and Optical Behavior of High Polymers", Jnl. of Physics D, (Applied Physics), 9, pp. 869-877 (1976).
10.
Theocaris, P.S., "Local Yielding Around a Crack Tip in Plexiglas ", Jnl. Appl. Mech., 37, pp. 409-415 (1970).
11.
Paipetis, S.A. , Papanicolaou, G.C. and Theocaris , P.S. "Dynamic Properties of Metal-filled Epoxy Polymers", Fibre Science and Technology , 8, pp. 221-242, (1975).
12.
Theocaris, P.S., Paipetis, S.A. and Papanicolaou , G.C., "Indentation Studies in Aluminum-Filled Epoxies," Jnl. of Applied Polymer Science , 22, pp. 2245- 2252 (1978).
13.
Papanicolaou, G.C., Paipetis, S.A. and Theocaris , P.S., "Thermal Properties of Metal-Filled Epoxies", Jnl. of Appl. Pol. Sci. , 21, pp. 689-701 (1977).
14.
Knauss, W.G. and Mueller, H.K., "Polymer Reinforcement from the Viewpoint of Fracture Mechanics", Proceedings of First USA-USSR symposium of Fracture of Composite Materials. Editors G. C. Sih and V. P. Tamuzs. Sept. 4-7 (1978 ).
15.
Theocaris, P.S. and Milios, J., "D ynamic Crack Propagation in Composites ", Int. Jnl. of Fracture, 16, No. 2, pp. 31-51 (1980).
16.
Theocaris, P.S. and Milios, J., "Crack Propagation Velocities in Bi-phase Plates Under Static and Dynamic Loading", Eng. Fracture Mechanics , 13, No. 4, pp. 599-609.
17.
Theocaris, P.S. and Milios, J., "Crack-Arest at a Bimaterial Interface ", to be published in Int. Jnl. Solids and Structures. 17, pp. 217-230 (1981).
18.
Theocaris, P.S. and Milios, J., "Crack-Arrest Modes of a Transverse Crack going through a Longitudinal Crack or a H ole", to be published in Jnl. of Eng. Mat. and Techn.
