Date of Award


Document Type


Degree Name

Master of Science


Department of Aeronautics and Astronautics


A finite element method, developed for static analysis of composite plates, was enhanced to be used with sandwich plates. The theory considers geometric nonlinearity and transverse shear. Furthermore, a new postprocessor was written to check for initial failure using the maximum stress criteria. It also includes a procedure for evaluating transverse normal stresses by enforcing equilibrium. The code modifications for sandwiches were verified by comparing finite element solutions to closed-form sandwich theories. Both methods showed good correlation. In addition, comparisons between one type of composite plate and a similar sandwich plate found that the sandwich had better specific stiffness for various geometries. Finally, quasi-static models of low-velocity impacts on sandwich plates succeeded in predicting incipient damage due to core crushing in the impact region, but they were inconsistent in estimating the actual load levels for initial failure, based on experiments from other research.

AFIT Designator


DTIC Accession Number