شبكة التخطيط العمراني بسم الله الرحمن الرحيم
للكاتبين Abdel-Lateef, T.H 1, Daboan, M.A.2,
Tohamy, S.A. 3, Abdel-Moez,O.M. 4 and Sadeek, A.B.5
1,3,4– Faculty of Eng., El-Minia Univ., Egypt.
2- Faculty of Eng., Tanta Univ., Egypt.
5- Faculty of Eng. & El-Azhar Univ. Qena , Egypt.
1-Abstract
The design of plate girders, like any other structures, is linked with many important
parameters. One of these important aspect is the interaction between the flange and web
which determines the capacity of the girder under loadings . In this paper a theoretical
analysis was carried out to investigate the buckling behavior of the web plate in plate girders
in the portion of the pure bending moment, i.e. in the case of simply supported beam subject
to symmetric concentrated loads.
The theoretical analysis is performed using the finite element program (ANSYS 5.4).Three
hundred dimensional finite element models ware examined to clarify the influence of
sectional compactness , aspect ratios of web panel and initial imperfections of webs on the
estimation of the critical load of plate girder under pure moment. An empirical formula to
estimate the critical load of plate girder under pure moment from load- lateral displacement
data is also proposed. The critical loads of such girders computed from the present prediction
equation were compared with those according to different methods .
The procedure adopted in the paper in directed to suggest some accurate and simple
procedures from which a fairly good estimate for the critical moment can be obtained, taking
into account the real boundary conditions between the web and the flanges. Thus, two
different suggestions were undertaken. The first formula can be used to determine the critical
moment from practical or theoretical data concerning the relationship between applied loads
and web out-of plane deformations. The second approach is concerned with the estimation of
the critical moment from a reasonably accurate and simple stress distribution on the cross
section.