A DOUBLY-CURVED FINITE ELEMENT ANALYSIS OF THIN ARBITRARY SHELL STRUCTURES by John Billings Burchnall Thesis submitted to the Graduate Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Civil Engineering APPROVED s'. °Chairman# v R. H. Plaut -E--.-S-om_e_r_s-,---=-J March, 1977 Blacksburg, Virginia