Document Type : Original Article


Structural Engineerr'ng Department, Faculty of Engineen'ng, EL-Mansoura University, Egypt


This paper presents both experimental and analytical investigations for the behaviour of flat plates
provided with drop parts formed by partially decreasing both top and bottom fibers of the plate.
The experimental study considers six plate specimens one of them is kept flat without any drop
parts to be the control case. The other specimens are provided with drop parts having the same
thickness of the plate while they are located at different locations of the plate. The locations of the
drops parts considered in the present study are the intersections of two middle strips, two column
strips and one middle-one column strips. All plates have the same thickness and the same aspect
ratio of 1.0. The plate specimens are supported on four concrete short columns located at the four
corners of the plate. The plates are subjected to uniformly-distributed flexural loading where the
cracking loads, the cracking patterns in both sides after failure, and the ultimate load are reported.
The Plate specimens are then taken up for a detailed nonlinear frnie element analysis where the
various types of stresses are obtained. The cracking patterns and the loaddeflection behaviour are
theoretically predicted for various plates. The study shows that the presence of drop parts in flat
plates has a significant effect on the mode of failure of the plate while this effect depends on the
location of the drop part. The stress distribution within the plate, the cracking and failure patterns
and the load-deflection behaviour of various plate specimens are also sensitive to the presence of
drop parts.