INTERLAMINAR STRESSES IN COMPOSITE LAMINATES-- A PERTURBATION ANALYSIS by Peter Wenhan Hsu Dissertation submitted to the Graduate Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Engineering Mechanics APPROVED: Prof. C. T. Herakovich, Chairman Prof. H. F. Brinson Prof. K. B. Hannsgen January, 1976 Blacksburg, Virginia Prof. D. Frederick Prof. E. G. Henneke