Investigation of Deep Beam by ANSYS and Codal provision.ppt

A
Presentation on
“Investigation of Deep Beam by ANSYS
and Codal provision”
By
Mrs. M. V. Sabale
1

1. INTRODUCTION
Deep beam can be defined as a beam having a ratio of span to
depth of about 2 or less. They are encountered in transfer girder, pile
cap, foundation wall, raft beam wall of rectangular tank, hopper, floor
diaphragm, shear wall. Because of their proportions deep beams are
likely to have strength controlled by shear rather than flexure [1]. In IS-
456(2000) clause 29, a simply supported beam is classified as deep
when the ratio of its effective span L to overall depth D is less than two.
Continuous beams are considered as deep when the ratio L/D is less
than 2.5. The effective span is defined as the centre-to-centre distance
between the supports or 1.15 times the clear span whichever is less.
Deep beams are usually loaded along the top edge with reactions
provided at the bottom. However, in some cases, e.g. the sidewalls of
storage bins, they may be applied along the bottom edge.
BVCOEK-NCETET-2023 2

Deep Beam has its useful applications in Water tanks (side walls): R. C.
C. side walls of water tank may act as deep beams, pile caps: pile caps
can also act as deep beams in case of smaller spans, raft foundations:
raft foundation may contain deep beams in some cases, bunkers and
Silos: Beams of these structures may act as deep beam, Shear Walls:
R.C.C. shear walls may act as deep beam etc. In deep beams, the
bending stress distribution across any transverse section deviates
appreciably from the straight line distribution assumed in the
elementary beam theory [1]. Consequently a transverse section which
is plane before bending does not remain approximately plane after
bending and the neutral axis does not usually lie at the mid depth. In
the case of deep beams, shear flexure and shear modes dominated by
tensile cleavage failure are common.
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Usually the problem addressed is too complicated to be solved
satisfactorily by classical analytical method [2]. The problem may
concern stress analysis, heat conduction, or any of several other areas.
The finite element procedure produces many simultaneous algebraic
equations which are generated and solved on digital computer. Finite
element calculations are performed on personal computers, mainframes,
and all sizes in between. Results are rarely exact. However, errors are
decreased by processing more equations, and results accurate for
engineering purposes are obtainable at reasonable effort.
The main objective of research work is to analyze a deep beam for
different length to span ratios by applying ANSYS 13.0 under two point
loading. The detailed analysis has been carried out using non-linear finite
element method and design using different codes.

2. ANSYS FINITE ELEMENT MODEL
The finite element analysis calibration study included modeling a
concrete beam with the dimensions and properties. To create the finite
element model in ANSYS 13.0 there are multiple tasks that have to be
completed for the model to run properly. Models can be created using
command prompt line input or the Graphical User Interface. For this
model, the graphical user interface was utilized to create the model.
This section describes the different tasks and entries to be used to
create the finite element calibration model.
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2.1 Element Types
The element type for this model is shown in TABLE 2.1. A solid65
element was used to model the concrete [3]. This element has eight
nodes with three degree of freedom at each node translations in the
nodal x, y, and z directions. The element is capable of plastic
deformation, cracking in three orthogonal directions and crushing. A
schematic view of the element is presented in Fig.2.1 (a).
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Material Type ANSYS Element
Concrete Solids65
Steel Reinforcement Link180
Table 2.1: Element Types for Working Model

(a)
(b)
Fig. 2.1: a) A Solid65 element b) Link 8 element

A Link180 element was used to model steel reinforcement. This
element is a 3D spar element and it has two nodes with three degrees
of freedom translations in the nodal x, y, and z directions. This element
was capable of plastic deformation and element is shown in Fig.2.1 (b).
8

2.2 Real Constants
Real Constant Set 1 was used for the Solid65 element [2]. It requires
real constants for rebar assuming a smeared model. Values can be
entered for Material Number, Volume Ratio, and Orientation Angles. The
material number refers to the type of material for the reinforcement.
The volume ratio refers to the ratio of steel to concrete in the element.
The reinforcement has uniaxial stiffness and the directional orientations
were defined by the user [4]. In the present study the beam was
modeled using discrete reinforcement. Therefore, a value of zero was
entered for all real constants, which turned the smeared reinforcement
capability of the Solid65 element of Real Constant Sets 2 and 3 were
defined for the Link8 element. Values for cross-sectional area and initial
strain were entered. Cross-sectional area in set 2 refers to the
reinforcement of two numbers of 10mm diameter bars.
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Cross-sectional area in set 3 refers to the 8 mm diameter two legged
stirrups. A value of zero was entered for the initial strain because there
is no initial stress in the reinforcement. The real constants were given in
TABLE 2.2.
10
Real
Constants
Element
Type
Rebar 1 Rebar 2 Rebar 3
1 Solid 65 Material no. V. R. 0 0 0
2 LINK 8
Area m2
78.5e - 6 - -
Initial strain 0 0 0
3 LINK 8
Area m2
50.24e-6 - -
Initial strain 0 0 0
Table 2.2: Real Constants

2.3 Beam Model
The beam was modeled following international specifications [1].
The model was 700 mm long with a cross section of 150 mm X 350 mm.
The Finite Element beam model is as shown in Fig. 2.2 (a). Detailed
dimensions for the concrete volume are presented in TABLE 2.3.
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ANSYS Concrete (mm)
X1, X2, X - coordinates 0, 700
Y1, Y2, Y - coordinates 0, 350
Z1, Z2, Z - coordinates 0, 150
Table 2.3: Dimensions for Concrete

2.4 Meshing Details for the Model
To obtain good results from the Solid65 element, the use of a rectangular
mesh was recommended [5]. Therefore, the mesh was set up such that square
or rectangular elements were created. The meshing of the reinforcement was a
special case compared to the volumes. No mesh of the reinforcement was
needed because individual elements were created in the modeling through the
nodes created by the mesh of the concrete volume. However, the necessary
mesh attributes as described above need to be set before each section of the
reinforcement is created. The meshing of the beam is presented in Fig.2.2 (a)
and (b).
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13
(a) (b)
Fig. 2.2: (a) Finite Element Beam Model (b) Reinforcement Configuration

2.5 Loads and Boundary Conditions
Displacement boundary conditions were needed to constraint the model
to get a unique solution. To ensure that the model acts the same way as the
experimental beam boundary conditions need to be applied at points of
symmetry, and where the supports and loading exist. The support was
modeled as a hinged support at both ends [6]. Nodes on the plate were given
constraint in all directions, applied as constant values of zero. The loading
and boundary conditions of the beam and the crack patterns of different
beams using ANSYS 13.0 software is presented in Fig.2.3 (a) and (b).
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15
(a) (b)
Fig.2.3: (a) Loading and boundary conditions (b) Crack patterns

3. ARESULTS AND DISCUSSIONS
3.1 Deflection for beam B1 using ANSYS 13.0 software:
• ***** POST1 NODAL DEGREE OF FREEDOM LISTING *****
• LOAD STEP= 1 SUBSTEP= 1
• TIME= 1.0000 LOAD CASE= 0
• THE FOLLOWING DEGREE OF FREEDOM RESULTS ARE IN THE GLOBAL
COORDINATE SYSTEM
• NODE UX UY UZ USUM
• 445 -0.60800E-04 0.39210E-02 0.55176E-05 0.39214E-02
• 446 -0.60800E-04 0.39210E-02-0.55176E-05 0.39214E-02
• 447 0.17767E-03 0.39384E-02 0.16486E-04 0.39424E-02
• 448 0.17767E-03 0.39384E-02-0.16486E-04 0.39424E-02
16

• 449 0.29120E-03 0.39734E-02 0.20956E-04 0.39841E-02
• 450 0.29120E-03 0.39734E-02-0.20956E-04 0.39841E-02
• 451 0.33275E-03 0.40624E-02 0.22548E-04 0.40761E-02
• 476 0.36065E-03 0.35078E-02-0.26384E-04 0.35264E-02
• 477 0.40712E-03 0.37039E-02 0.20969E-04 0.37263E-02
• 478 0.40712E-03 0.37039E-02-0.20969E-04 0.37263E-02
• 479 0.50201E-03 0.38606E-02 0.17697E-04 0.38932E-02
• 480 0.50201E-03 0.38606E-02-0.17697E-04 0.38932E-02
•
• MAXIMUM ABSOLUTE VALUES
• NODE 298 150 162 150
• VALUE 0.66192E-03 0.49735E-02-0.42005E-03 0.49750E-02
17

Section 3.1 is the specimen output of the computer after uploading
all required variables and constants for beam B1 required for running
the ANSYS 13.0 software. Output result graph for the analytical and
ANSYS 13.0 is presented in Fig. 3.1 (a) and (b).
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Fig. 3.1 (a): Computer Output specimen for ANSYS 13.0

19
Fig. 3.1 (b): Computer Output specimen for ANSYS 13.0

20
Fig. 3.2: Comparison of Beam deflection for different beams

3.2 Comparative Analysis of Load-Displacement Curve and Load Carrying
Capacity:
Comparisons of test data with ANSYS simulations are shown in Fig.3.2.
The cracking load and ultimate load of twelve deep beams are presented in
Fig. 3.2. According to the 1–7 beams, it can be seen that the load
displacement curve of the finite element is basically consistent with that of
the test, and the gap of the failure load is not big [7]. But the slope of the
curve obtained by finite element method is slightly larger than that of the
test chamber. The stiffness of the beam simulated by the finite element is
slightly more than that of the test result [8]. The main reason for this
situation is the simulation of concrete inner was ideal and with no flaw. In
addition, due to the compacting process of beams in the actual process, the
stiffness of the beam simulated by ANSYS is greater than that of test beam.
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From Fig. 3.2, the finite element simulation results showed that, in the
aspect of cracking loads, the cracking load of the test beam increases with
the increase of volume fraction of steel fiber [9], which reflected that the
initial cracking of the steel fiber can be suppressed by the addition of steel
fiber [10]. However, the cracking load of beam3 is smaller than that of
beam2, which could be caused by the uneven mixing of steel fiber. The
smeared crack model was used in ANSYS to simulate the distribution and
development of cracks, with the lack of ability to simulate single fracture
of crack width and crack development [11]. From the crack distribution, it
can be seen that the ordinary concrete beam cracks almost distributed in
the whole beam section, and the results gained from half length of the
beams were compared in Fig.3.2. Shown by the comparison, the fracture
distributions simulated by finite element are in a good conformation with
the fracture distributions during actual test [12].
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4. CONCLUSIONS
• Deep beams having different L/D ratios were analyzed by using various
codes and by using software and tested under two point loading. Some
prominent conclusions were summarized here.
1) STRENGTH
• As per the code provisions it was observed that, as L/D ratio decreases
there is an increase in the strength of deep beams.
• The strength of deep beam having,
• L/D ratio 1.71 is 15.96% more in IS code (B1) than in CIRIA Guide (B7).
23

2) DEFLECTION:
• It was observed that deflection of specimen designed as per
provisions of CIRIA Guide is more than the specimen designed as per
IS Code.
• Deflection of deep beam designed as per IS Code is more than
analytical deflection.
• Deflection of deep beam designed as per CIRIA Guide is more than
analytical deflection.
• It was observed that, as depth of deep beam increases deflection of
beam decreases.
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REFERENCES:
[1] Mohammad Abdur Rashid and Ahsanul Kabir, Behaviour of Reinforced Concrete Deep Beam Under
Uniform Loading, Journal Of Civil Engineering The Institution of Engineers, Bangladesh, 24
(2),1996,86–114.
[2] B.R. Niranjan, S.S.Patil.(2012), Analysis of R.C Deep Beam by Finite Element Method, International
Journal of Modern Engineering Research, 2(6), 2012,4664-4667 ISSN: 2249-6645.
[3]Kavya K. Kumar, Ramadass S. and Vivek Philip (2015), “A Study on Concrete Deep Beams
using Nonlinear Analysis”, IJIRST –International Journal for Innovative Research in Science
& Technology| Volume 2 | Issue 05 | October 2015 ISSN (online): 2349-6010.
[4] S. S. Patil, A. N. Shaikh, B. R. Niranjan (2013), “ Experimental and Analytical Study on
Reinforced Concrete Deep Beam”, International Journal of Modern Engineering Research
(IJMER), Vol.3, Issue.1, Jan-Feb. 2013 pp-45-52 ISSN: 2249-6645.
[5] Sudarshan D. Kore, S.S. Patil,(2013) “Analysis and Design of R.C. Deep Beams Using
Code Provisions of Different Countries and Their Comparison”, International Journal of Engineering
and Advanced Technology (IJEAT) ISSN: 2249 – 8958, Volume-2, Issue-3, February 2013.
25

[6] Kale Shrikant M., Patil.S.S., Niranjan B.R.(2012), “Analysis of Deep Beam Using Cast
Software and Compression of Analytical Strain with Experimental Strain Results”,
International Journal Of Computational Engineering Research (ijceronline.com) Vol. 2 Issue.
8, Issn 2250-3005(online), December, 2012, Page 181.
[7] Enem, J. I.,Ezeh, J. C., Mbagiorgu, M.S.W., Onwuka, D.O. (2012), “Analysis of deep beam using
Finite Element Method”, Int. Journal of Applied Science and Engineeing Research, Vol. 1, No. 2,
2012.
[8] Shamsoon Fareed; S.F.A.Rafeeqi and Shuaib H. Ahmad (2012), “Shear Strength ofNormal and
Light Weight Reinforced Concrete Deep and Short Beams Without Reinforcement”, Research
Journal in Engineering and Applied Sciences 1(1) (2012) 1-6.
[9] Vinu R. Patel, I. I. Pandya (2012), “Ultimate shear strength of Fibrous moderate deep Beams
without stirrups”, Int. Journal of Applied Sciences and Engineering Research, Vol. 1, No.2, 2012.
[10] K. H. Yang and A. F. Ashour (2008), “Effectiveness of Web Reinforcement around Openings in
Continuous Concrete Deep Beams”, ACI Structural Journal, Vol. 105(4), pp. 414-424.
[11] Khalaf Ibrahem Mohammad (2007), “Prediction Of Behaviour Of Reinforced Concrete
DeepBeams with Web Openings Using Finite Elements”, Al-Rafidain Engineering Vol.15 No.4 2007.
[12] Wen-Yao Lu (2006). “Shear Strength prediction for steel reinforced concrete deep beams”,
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ACKNOWLEDGEMENTS:
Authors wholeheartedly acknowledge the constant encourage and
motivation by Ex. Director, Principal and the senior staff of Civil
Engineering Department in preparing this research work.
Authors also thank the support staff for their assistance in preparing
the report of the work and other related non-technical contribution.
27

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