Failure Analysis of a Graphite/Epoxy Laminate Subjected to Combined Thermal and Mechanical Loading

Abstract

Quasi-static thermal stress response and failure behavior of graphite/epoxy lam inated plates under combined intense thermal and mechanical loadings are investigated. The temperature field is obtained by using a one-dimensional finite difference code. The effects of ablation, degradation of thermophysical properties at elevated tem peratures, and radiation and convective heat losses are included in the formulation. In the thermal stress and strength analyses, the temperature-dependent mechanical prop erties and temperature-dependent strengths are used. A nine-node isoparametric finite element is employed to calculate the structural responses. The maximum stress criterion is adopted for failure predictions. Numerical results include the temperature distributions over the thickness of the plate, structural responses, and time to failure. The analytical predictions are compared with experimental data.

References

Pell, W.H. , "Thermal Deflections of Anisotropic Thin Plate," Q. Appl. Math., Vol. 4, pp. 27-44 (1946).

Stavsky, Y. , "Thermoelasticity of Heterogeneous Aeolotropic Plates," J. Eng. Mech. Div., Proc. ASCE, Vol. 89, pp. 89-105 (1963).

Misra, J.C. , "On the Bending of a Heated Rectangular Anisotropic Plate with Two Opposite Edges Simply Supported and Two Others Built In, Due to Different Temperature Distribution On the Plane Surface," Bull. Calcutta Math. Soc., Vol. 63, pp. 183-190 (1971).

Wu, C.H. and Tauchert, T.R. , "Thermoelastic Analysis of Laminated Plates 1: Symmetric Special Orthotropic Laminates," J. Thermal Stresses, Vol. 3, pp.247-259 (1980).

Wu, C.H. and Tauchert, T.R. , "Thermoelastic Analysis of Laminated Plates 2: Antisymmetric Cross-ply and Angle-ply Laminates," J. Thermal Stresses, Vol. 3, pp. 365-378 (1980).

Reddy, J.N. and Hsu, Y.S. , "Effects of Shear Deformation and Anisotropy on the Thermal Bending of Layered Composite Plates," J. Thermal Stresses , Vol. 3, pp. 475-493 (1980).

Hsu, Y.S. , Reddy, J.N. and Bert, C.W. , "Thermoelasticity of Circular Cylindrical Shells Laminated of Bimodulus Composite Materials," J. Thermal Stresses , Vol. 4, pp. 155-177 (1981).

Weinstein, F. , Putter, S. and Stavsky, Y. , "Thermoelastic Stress Analysis of Anisotropic Composite Sandwich Plates by Finite Element Method," Comput. Struct., Vol. 6, pp. 31-36 (1983).

Parida, J. and Das, A.K. , "Thermal Stresses in a Thin Circular Disc of Orthotropic Matenal Due to an Instantaneous Point Heat Source," Acta Mech ., Vol. 13, pp. 205-214 (1972).

10.

Huang, C.L.D. and Woo, H.K. , "The Fundamental Heat Conduction Solution for a Thermal Shock on a Finite Orthotropic Cylindrical Thin Shell," Nucl. Eng. Des., Vol. 45, pp. 67-79 (1978).

11.

Huang, C.L.D. and Woo, H.K. , "Thermal Stresses and Displacements Induced in a Finite Orthotropic Cylindrical Thin Shell by an Instantaneous Shock," J. Thermal Stresses, Vol. 3, pp. 277-293 (1980).

12.

Pering, G.A. , Farrell, P.V. and Springer, G.S. , "Degradation of Tensile and Shear Properties of Composite Exposed to Fire or High Temperature," J. Comp. Materials, Vol. 14, pp. 54-68 (1980).

13.

Griffis, C.A. , Masumura, R.A. and Chang, C.I. , "Thermal Response of Graphite/Epoxy Composite Subjected to Rapid Heating," J. Comp. Materials , Vol. 15, pp. 427-442 (1981).

14.

Sun, C.T. and Chen, J.K. , "Transient Thermal Stress Analysis in Graphite/Epoxy Composite Laminates," Developments in Theo. and Appl. Mech ., Vol. XI, Edited by T. J. Chung etc., pp. 309-328 (April 1982).

15.

Hobbs, N.P. , Dalton, T.A. and Smiley, R.F. , "TRAP2-A Digital Computer Program for Calculating the Response of Mechanically Loaded Structures to Laser Irradiation," KATR-143 Kamon Avidyne (Burlington, Mass.) (October 1977).

16.

Jone, R.M. , Mechanics of Composite Materials, Scripta Book Company, Washington, D.C. (1975).

17.

Zienkiewicz, O.C. , Taylor, R.L. and Too, J.M. , "Reduced Integration Technique in General Analysis of Plate and Shell," Int. J. Num. Meth. Eng ., Vol. 3, pp. 575-586 (1971).