الفهرس 
CHAPTER (1): INTRODUCTION.Only 14 pages are availabe for public view
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Abstract
Many older structures were designed for static loads, but recently, there
has been a growing awareness that some must be designed to resist both
dynamic and static loads.
Impact load is one of the most dangerous dynamic loads, which can affect
structural components. Hence, recently, there is an accelerating interest for
researchers to understand the behavior of different structural components under
impact loading in order to provide design methods that can withstand this load
condition.
A large proportion of the surfaces of concrete structures are covered by
reinforced concrete slabs (plates) which are often slender elements and
consequently are vulnerable to flexural, shear, or a combination of both modes
of failure when subjected to impact loading.
Concrete slabs usually have openings for different structural and
architectural purposes. So, the main aim of this research is to investigate impact
load effects on RC plates with openings. For this purpose, a 3D finite element
model using Abaqus 6.13 software is presented. The work was established in
three stages:
In the first stage, the generated FE model was verified against three
previously published experimental investigations on RC plates under impact.
All verified plates were without openings. The presented FE model was capable
of predicting the real behavior of plates under impact as it showed good
agreement with the published experimental work results.
In the second stage, one analysis of the verified model was selected to
investigate dynamic behavior of plates with openings under impact; a series of
FE model runs with different positions, numbers and shapes of openings were
built and analyzed under the same conditions of the original one. It was
concluded that the worst performance of plates regarding to failure pattern and
maximum mid-point deflection, was for those with circular and square openings
at mid side of plate.
Based on previous stage, the last step was to execute an experimental
program which was mainly designed to investigate the effect of enhancing
plate’s behavior which showed the worst one using two types of reinforcing
metal meshes; welded and expanded. The program included casting and testing
seven specimens of RC plates with dimensions 1100 × 1100 × 30 mm and
reinforced with 1Ø6 every 150 mm. The measured results obtained from
experimental investigations were verified with the results of generated FE
model runs and an excellent agreement was achieved. It was concluded that
using expanded and welded metal meshes, improve the behavior of all plates
and reduces effect of opening on deflection and cracking pattern.