FRP
pultruded profiles having I-shaped sections are used as load bearing
compression and flexural members in
truss and frame structures. For design
purposes closed form expressions are desired for predicting both global and
local failure loads due to
buckling or material rupture. A set of closed-form
equations has been assembled from the technical literature for the prediction
of the critical local and global failure modes of pultruded columns needed for
design. A database of tests on pultruded columns conducted over the last 15
years and reported in the technical literature was used to verify the accuracy
of the proposed theoretical equations. Only those test data for which the
measured orthotropic material properties of the profiles tested were reported were
considered. This paper presents comparisons between the theoretical equations
and test data for wide-flange pultruded columns for two failure modes,
local-flange buckling and global-flexural buckling. Insufficient test data
exist in the literature on other profiles (such as narrow flange I beams or box
sections) or for failure modes other than those noted. However, since most
pultruded columns used are of the wide-flange profile type and have been shown
to fail either in local or global buckling modes, the results presented are of
practical importance. The paper also addresses the phenomenon of the
interaction of local and global buckling modes for intermediate length columns.
Ultimately, the results of this investigation will be used to develop resistance
factors for a load and resistance factor design (LRFD) basis for pultruded
columns.