الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Deep beams are fairly commonly used as load distribution elements such as
transfer girders, pile caps, tank walls, diaphragm beams for folded plates, and foundation
walls, often receiving many small loads and transferring them to a small number of
reaction points. In the present work, the shear strengthening of reinforced concrete deep
beams using FRP composite materials is studied. Finite element (FE) models for
reinforced concrete deep beams strengthened with FRP composites are implemented and
validated against various experimental results published in the literature. Generally, the
predicted finite element results achieved a good correlation with the available
experimental results. Then, parametric studies are developed present the effect of the
different parameters on the structural performance of reinforced concrete deep beams
strengthened with FRP composites. Finally, a modified strut-and-tie model (STM) is
presented as an analysis and design tool for FRP-strengthened inforced concrete deep
beams.
For nonlinear analysis of reinforced concrete deep beams strengthened using FRP
composites, 3-D finite element model for FRP-strengthened reinforced concrete deep
beam is developed. Also, the material models are presented for concrete, steel and RP
behaviors in compression and tension. A brief description to ANSYS computer program
is illustrated with including definitions of different element types, loading boundary
conditions, meshing and simulation techniques. A brief introduction to onvergence,
solution procedures, methodology and failure criteria is given as well. The alidation
studies include multiple groups for modeling deep beams with different material
properties, specimen geometry, FRP strengthening methods, applied loads, steel
configurations and meshing techniques in order to verify the ability of ANSYS software
to perform finite element models for deep beams. For all studied cases, good correlation
is shown from the comparison between the experimental and the predicted results which
include the load-deflection curves and crack patterns. Also, parametric studies for FRP
strengthened reinforced concrete deep beams are performed in order to assess the shear
strength for deep beams strengthened by FRP composite aterials. The main arameters
studied herein include the effect of material and geometry parameters such as concrete
strength (fc`), yield strength of longitudinal steel (fy) and shear span to depth ratio (a/d),
the effect of reinforcement steel ratio parameters such as ratio of flexure steel, ratio of
horizontal stirrups and vertical stirrups, the effect of FRP sheets parameters such as
thickness of FRP sheets, angle of FRP fibers, length of strengthening and FRP sheets
material and the effect of FRP strips parameters such as thickness of FRP strips, angle of
FRP strips, spacing between FRP strips and FRP strips material.
Applying the modified STM to predict the shear capacity of 55 specimens in the
literature showed that the modified STM is performing well in estimating the ultimate
loads of reinforced concrete deep beams strengthened with FRP composites. The overall
average value of the ratio between the experimental capacity to the theoretical capacity of
the proposed STM (Pu(EXP) / Pu(STM) ) is of value 1.06 with a standard deviation of 0.16.
Using the modified STM, parametric studies are performed to study the effect of different
parameters including parameters of FRP strengthening materials, concrete compressive
strength (fc`) and (a/d) ratio on the ratio between (Pu,STR./Pu,UNSTR)