This paper describes results from combined experimental and theoretica
l studies of compressive failures of polymer matrix glass reinforced c
omposites which have undergone thermal loading. The materials discusse
d herein ave composed of vinylester resins and E-glass, quasi-isotropi
c, fabrics with relatively high fiber densities in the 55 volume perce
nt range. Both single skin and coved composite materials are addressed
in our studies but the focus of the present paper is on single skin c
omposites. Experimental studies have included structural collapse unde
r combined thermal (i.e. fire) and mechanical loading; the mechanical
loading included combined in-plane and out-of-plane loading of panels
which were approximately 1 m(2). Our theoretical studies include detai
led finite element simulations of panel deformation and collapse to be
compared with the experimental observations. The approach to the deve
lopment of a quantitative methodology for structural fire protection i
s discussed in the context of the experiments and analyses. This appro
ach is outlined using a simple analytical model for structural collaps
e; the model's predictions are compared with experiment and the numeri
cal simulations.