tan hock hee

ANALYSIS OF STRUCTURAL BEHAVIOUR OF 3D SLENDER COUPLED

SHEAR WALL WITH OPENING USING ANSYS SOFTWARE

TAN HOCK HEE

Thesis submitted in partial fulfilment of the requirements

for the award of the degree of

B.Eng. (Hons.) Civil Engineering

Faculty of Civil Engineering & Earth Resources

UNIVERSITI MALAYSIA PAHANG

JUNE 2015

vi

ABSTRACTS

Shear wall is one of the structural system which is used to resist the vertical and the lateral

load of the building. Due to the architectural and the ventilation reason, usually there are

some opening on shear wall. In most of the apartment building, the size and location of

the opening in the shear wall are made without considering the effect on the shear wall

and will contribute to the structural failure. The main objectives of this study is to

determine the effect of the opening size and its location on shear wall in terms of the crack

pattern and drift effect. This study is carried out on 4-storey shear wall building with the

help of finite element software, ANSYS 12.0. There are eight model in this analysis which

is SW1, SW2, SW3, SW4, SW5, SW6, SW7 and SW8. SW1 are the solid shear wall

where the SW2, SW3, SW4, SW5, SW6, SW7 and SW8 was the shear wall with different

opening size and location. The model was analyzed by using the lateral uniform

distributed load (UDL) at the side of the shear wall. The result shows that the higher the

applied load at the shear wall, the higher the deflection. The deflection for SW1, SW2,

SW3, SW4, SW5, and SW6 increased by 12.01%, 133.95%, 2.48%, 67.29%, 22.51% and

35.79% respectively when the applied lateral load was increase from 200KPa until

800KPa. While the closer the position of the opening to the applied UDL, the higher the

crack pattern of the shear wall. The crack pattern of the shear wall start at the base of the

shear wall which was the fixed support, and also the edge of the opening.

vii

ABSTRAK

Dinding ricih adalah salah satu sistem struktur yang digunakan untuk menahan beban

daripada atas dan beban yang melintang bagi sesebuah bangunan. Oleh kerana

pengudaraan dan kegunaan arkitek, dinding ricih akan ada beberapa pembukaan yang

tidak dapat dielakkan. Kebiasaan pada apartmen, terdapat banyak saiz dan lokasi

pembukaan yang dibuat secara tidak memikirkan kesan daripada pembukaan dan ia akan

menyebabkan struktur kegagalan. Objektif bagi kajian ini adalah untuk mencarikan kesan

daripada saiz dan lokasi pembukaan pada dinding ricih dalam aspek corak retak dan juga

kepesongan. Kajian ini adalah dinding ricih yang setinggi empat tingkat akan dianalisis

dengan menggunakan bantuan daripada perisian, ANSYS 12.0. terdapat lapan buah

model yang akan dianalisis, iaitu, SW1, SW2, SW3, SW4, SW5, SW6, SW7 dan SW8.

SW1 adalah dinding yang padat dan tidak mempunyai pembukaan, manakala SW2, SW3,

SW4, SW5, SW6, SW7 dan SW8 adalah dinding yang mempunyai saiz pembukaan dan

lokasi pembukaan yang berbeza-beza. Model-model dianalisis dengan munggunakan

beban teragih seragam pada tepi dinding. Hasil memberikan bahawa semakin tinggi

beban yang dikenakan pada dinding, semakin besar kepesongan pada dinding tersebut.

Kepesongan pada SW1, SW2, SW3, SW4, SW5, dan SW6 meningkat sebanyak 12.01%,

133.95%, 2.48%, 67.29%, 22.51% dan 35.79% apabila beban yang dikenakan meningkat

daripada 200KPa kepada 800KPa. Bagi pembukaan dinding yang terletak lebih dekat

dengan beban, corak retak menjadi semakin besar. Corak retak bermula pada bahagian

bawah dinding iaitu pada tempat yang dijadikan tetap, dan juga akan terletak pada bucu-

bucu lubang.

viii

TABLE OF CONTENTS

SUPERVISOR ‘S DECLARATION ii

STUDENT’S DECLARATION iii

DEDICATION iv

ACKNOWLEDGEMENT v

ABSTRACT vi

ABSTRAK vii

TABLE OF CONTENT viii

LIST OF FIGURES x

LIST OF TABLES

xiv

CHAPTER 1 INTRODUCTION

1.1 General 1

1.2 Problem Statement 2

1.3 Objectives of study 3

1.4 Scope of Study

3

CHAPTER 2 LITERATURE REVIEW

2.1 General 8

2.2 Use of Shear wall 8

2.3 Advantages of Shear Wall 10

2.4 Application of Shear Wall 10

2.5 Slenderness Ratio 11

2.5.1 Slender Wall 12

2.5.2 Squat Wall 12

2.6 Reinforcing Bar 12

2.7 Solid 65 Element 13

2.8 Link 8 13

2.9 Effect of Size Opening to Performance of Shear Wall 14

ix

2.10 Effect of opening location to performance of shear wall 15

2.11 Crack pattern 15

2.12 Drift effect of shear wall

16

CHAPTER 3 METHODOLOGY

3.1 General 18

3.2 Flow chart of methodology 18

3.3 Pre-processor 20

3.4 Solution 34

3.5 Post-processor

39

CHAPTER 4 RESULTS AND DISCUSSION

4.1 General 42

4.2 Drift Effect 42

4.3 Crack Pattern

44

CHAPTER 5 CONCLUSIONS

5.1 Conclusions 58

5.2 Recommendations

59

REFERENCES 60

APPENDICES 62

A Results of Deflection of Shear Wall 63

x

LIST OF FIGURES

Figure No.

Title Page

1.1

Reinforcing bar arrangement 5

1.2

Dimension of the shear wall 6

2.1

Reinforced concrete shear wall 9

2.2

Shear wall layout 11

2.3

Geometry of solid 65 13

2.4

Link 8 14

3.1

Flow chart of the analysis 19

3.2

Element type of the model 21

3.3

Adding the real constant for the model 21

3.4

Cross sectional area of the steel bar 22

3.5

Choosing material properties 22

3.6

Inserting the young modulus and poison ratio 23

3.7

Inserting the yield stress 23

3.8

Selecting the material properties of concrete 24

3.9

Inserting the young modulus and poison ratio for concrete

24

3.10

Inserting the material properties for concrete 25

3.11

Creating the shear wall by using block 25

3.12

Selecting area by select entities 26

3.13

Copy area to define location of steel bar 27

3.14

Copy area according to location of steel bar 27

3.15

Lines of area which shows the location of the steel bar 28

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3.16

Selecting the block of the opening at the shear wall for

creating opening

28

3.17

Sample of shear wall with opening after subtract the

volume

29

3.18

Trim the excess area after creating the model 29

3.19

Merging the nodes according to the lowest number 30

3.20

Selecting the lines that represent the steel bars 30

3.21

Unselecting the lines that is unneeded 31

3.22

Creating the lines into a component 31

3.23

Inserting the value for mesh concrete 32

3.24 Inserting the value for mesh the lines for define the steel

bar

32

3.25 Selecting the element type, material number, and real

constant set number for concrete

33

3.26 Selecting the component lines for meshing

33

3.27 Choosing the element types, material number, and real

constant set number for the steel bars

34

3.28 Selecting all the nodes that located at the base of the shear

wall

34

3.29 The nodes that selected was constrained in all dof

35

3.30 Select the nodes at the sides of the shear wall for applying

the pressure load

35

3.31 Inserting the pressure load that will applied to the shear

wall

36

3.32 Setting of the analysis types

36

3.33 Setting of the time at the end of load-step, time increment

setting and setting the time step size, minimum time step

and maximum time steps

37

3.34 Setting of the frequency was set as “write every sub-step

37

xii

3.35 Setting of nonlinear option which the line search, dof

solution and maximum number of iteration

38

3.36 Setting of termination criteria of the program behaviour

upon non-convergence

38

3.37 Solve the analysis by “solve current ls”

39

3.38 The result of the whole analysis was read “by load step”

39

3.39 The deformed shape was plotted

40

3.40 Plotting the nodal solution

40

3.41 Plotting the stress for each direction

41

3.42 Plotting crack/ crush of the concrete

41

4.1 Crack Pattern Of Solid Shear Wall (SW1) Under 800kpa

Load

46

4.2 Crack Pattern Of Shear Wall (SW2) Under 800kpa Load

46


47


47


49


49


50


50


51


51


52


52


53


53


54

xiii


54

4.17 Crack Pattern Under 800kpa Load For SW5

55


56


56


57

xiv

LIST OF TABLES

Table No.

Title Page

1.1 Concrete properties prior and parameters beyond initial yield

surface

3

1.2 Properties for smeared steel reinforcement

4

1.3 List of the detailing of the shear wall model

7

3.1 Concrete properties prior and parameters beyond initial yield

surface

20

3.2 Properties for smeared steel reinforcement

20

4.1 Deflection of shear wall

43

CHAPTER 1

INTRODUCTION

1.1 GENERAL

Nowadays, due to the economic growth and the demand for the business and

residential space increased, the demand for the high rise building is getting higher. The

high rise building needs well designed structural system to support the whole building to

resists the vertical load and lateral load such as the live load, dead load, and the wind load.

The structural system include of moment resisting frame system, shear wall frame system,

tubular system, hybrid system, bundle tubes system and etc. Apartment, commercial

tower and also the office tower were commonly using the shear wall as the structural wall

system to resist the vertical and also the lateral load of the high rise building.

Shear wall is one of the structural wall system and it provides strength, stiffness

and stability to resist the vertical load and lateral load force such as wind and earthquake

load for ensure the safety of the whole building. Shear wall are considerable deeper than

normal beam and column and this result in makes shear wall as a natural choice for resist

wind load. Shear wall is reinforced wall which is casted using the concrete and

reinforcement steel bar and it’s likely vertically oriented wide beam which is used to resist

the lateral load. Shear wall can be classified into two types. The wall with aspect ratios

(wall height to wall width) of 2 or more is called as slender wall while for aspect ratio

with less than 2 called as squat wall. (Gaynor. P.J, 1988).

Due to the architectural reason, shear wall often faces to the opening at the outer

wall like window, door, corridor and also some opening for the lift core for high rise

building. The number, size and the location of the opening will affect the structural wall

2

strength and the stiffness of the wall. (Taleb, R. 2010). The load carrying capacity of a

shear wall is higher for wall without opening. (PoojaHegde and Itti 2014,). Therefore for

the shear wall with opening must have adequate designed and analyzed to ensure the

safety of the building. The edge of the shear wall will have higher stress which stress will

concentrate at the edge of the opening and this will lead to the cracking at the edge corner.

The use of the diagonal shear reinforcement was introduced for significant contribution

for retarding and slowing down the crack propagation.

1.2 PROBLEM STATEMENT

Nowadays due to the development and increase in population and income, it has

lead for increase in the housing demand. The working group indirectly increased the

demand for housing when they have the purchasing power to do so. The increase in the

demand for the housing in the major urban area has resulted in the rapid development in

high rise residential schemes. (Tiun.L.T, 2003) So construction of the high rise building

in Malaysia is become more popular and this result to needs suitable design in high rise

building.

Shear wall is one of the structural system which is used to resist the vertical and

the lateral load of the building. Due to the architectural and the ventilation reason, there

are some opening at the shear wall and these opening will affect the strength of the shear

wall. The strength, stability and also the stiffness of the shear wall will various with

different dimension and location of the opening. According to the (Taleb, R. 2010), the

number, size and location of the opening will affect the structural wall strength and the

stiffness of the wall. In the conclusion, the stress distribution and the drift of the shear

wall will various with the different size of the opening and the location of the shear wall

and it must be analyze well so that the structural failure can be prevented.

3

1.3 OBJECTIVE OF STUDY

The main objective of this study are:

i. To analyse the effect of the opening size at the shear wall in terms of the drift

effect and crack pattern of the shear wall.

ii. To analyse the effect of the opening location at the shear wall in terms of the

crack pattern of the shear wall.

1.4 SCOPE OF STUDY

The scope of study is focused on the effect of opening size at the shear wall and

the location of the opening of shear wall. This is study the effect to the shear wall when

there is opening on it and various location of the opening. The larger the size of the

opening, is the greater the stress flow disturbance within the shear wall. (Musmar, A.M.

2013). The model of the reinforcing arrangement is adopted from the (Lefas and

Ambraseys 1990). The model is in 4 floor height with 3.0m for each floor, the width of

the wall is 3.0m and the thickness of the wall is 0.3m. The Table 1.1, and Table 1.2 shows

the concrete properties, concrete parameter and properties for smeared steel

reinforcement respectively which is refer from the previous study conducted by (Musmar,

2013).

Table 1.1: Concrete Properties Prior and Parameters beyond Initial Yield Surface

Material model Linear Elastic

Modulus of elasticity MPa 25743

Poisson Ratio 0.3

Open shear transfer coefficient 0.2

Closed shear transfer coefficient 0.9

Uniaxial cracking stress 3.78MPa

Uniaxial crushing stress f ́c 30MPa

4

Table 1.2: Properties for Smeared Steel Reinforcement

Material model prior to initial yield surface linear elastic

Elastic modulus, Es 200 GPa

Poisson's ratio 0.3

Yield stress, fy 412 MPa

Material model beyond initial yield surface and up to failure

perfect plastic

There are eight models of the shear wall been model and analysed by using

ANSYS software. Model with no opening are designated as SW1. Hence, model with

different opening of 1.2 m x 0.6 m, 1.5 m x 0.6 m and 1.8 m x 0.6 m was designated as

SW2, SW3 and SW4 respectively. Besides that, model with opening at the middle, one-

third, quarter, two-third, and third-quarter from the left of the wall was designated as SW5,

SW6, SW7 and SW8 respectively. The dimension and the location of the opening is

tabulated at the Figure 1.1 and Figure 1.2 at below. The reinforcing bar arrangement of

the shear wall is shown at below which is referred to (Lefas and Ambraseys 1990). The

vertical and the horizontal reinforcement comprised high tensile deformed steel bars of

12mm diameter. The spacing for the vertical bar is 200mm from centre to centre of the

reinforcing bar while the horizontal spacing is 200mm from centre to centre of the bars.

5

Figure 1.1: Reinforcing bar arrangement

6

Figure 1.2: Dimension of the shear wall

7

Table 1.3: List of the detailing of the shear wall model

Model designated

Wall size (mm) w x h

OPENING(mm) a x b

w1 (mm)

h1 (mm)

h2 (mm)

SW1 3100 x 12100 - - - -

SW2 3100 x 12100 600 x 1200 1200 900 1800

SW3 3100 x 12100 600 x 1500 1200 750 1500

SW4 3100 x 12100 600 x 1800 1200 600 1200

SW5 3100 x 12100 600 x 1200 700 900 1800

SW6 3100 x 12100 600 x 1200 450 900 1800

SW7 3100 x 12100 600 x 1200 1750 900 1800

SW8 3100 x 12100 600 x 1200 2000 900 1800

The suitable size and location of the opening of a shear wall was studied. To do

this research, ANSYS was chosen to do the analysis of the effect of opening shear wall.

This study used ANSYS to do the modelling of the shear wall and analysed the shear wall

to determine the stress distribution and also drift of the shear wall. Solid element under

concrete 65 was used for the concrete and the link element link 8 was used for the Rebar

in concrete as a reinforcing material when modelling the shear wall using ANSYS.

SOLID65 element was used for the three-dimensional modelling of solids with or without

reinforcing bars.

The capacity of the structure is represented by load displacement curve, obtained

by non-linear static analysis, where the load is stepwise increased. This is used in

conducting non-linear analysis for shear wall utilizing ANSYS finite element software

and also adopting a fixed support condition along the base of the whole shear wall. The

load are applied horizontally on the left of the wall at the top of the shear wall. The

research is study the effect of shear wall with opening under different type of uniform

distributed load in terms of the total drift effect and crack pattern.

CHAPTER 2

LITERATURE REVIEW

2.1 GENERAL

Nowadays due to the development and increase in population and income in

Malaysia, it has lead for increase in residential space and also housing demand. The

increase in the demand for the housing in the major urban area has resulted in the rapid

development in high rise residential schemes. (Tiun, L.T. 2003) So construction of the

high rise building in Malaysia is become more popular and this needs well designed

structural system to support the whole building to resists the vertical load and lateral load

such as the live load, dead load, and the wind load. The structural systems include of

moment resisting frame system, shear wall frame system, tubular system, hybrid system,

bundle tubes system and etc. Apartment, commercial tower and also the office tower were

commonly using the shear wall as the structural wall system to resist the vertical and also

the lateral load of the high rise building.

2.2 USE OF SHEAR WALL

Shear wall is one of the lateral load resisting wall system which is generally start

at the foundation level and it continuously throughout the building height until to the top

of the building. The thickness of the shear wall can be from 150mm to maximum of

400mm thick in high rise building. (Pooja Hegde 2014). Shear wall is designed to resist

shear or the lateral forces acting to the structure. They are the vertical elements in the

horizontal force resisting systems. (McCormick 2009). The stiffness of the overall

structure is drastically increased when shear walls are provided. Basically, the shear walls

9

are implemented at locations prone to lateral forces like earthquakes motion, wind forces

etc.

Figure 2.1: Reinforced Concrete shear wall

Source: Meena Shrestha 2008

Meena Shrestha (2008) said that behaviour of shear wall tends to change from

coupled wall system to two independent walls as the opening area is increased. Figure 2.1

above shows the sample of the reinforced concrete shear wall. With the same rate of an

increment in opening area, the rate of decrease in interaction between walls with an

increase in width of doors has been found higher than that with an increase in height of

windows with a constant distance between the floor level and the bottom of the windows.

Medhekar and Sudhir (1993) concluded that shear wall are suitable for the

earthquake resisting structure in induced lateral forces in multi-storeyed building system.

Shear wall can be made to behave in a ductile manner by adopting proper detailing

techniques.

10

2.3 ADVANTAGES OF SHEAR WALL

Wind load is one of the lateral force that causing to the snap the structure in shear

and push it over in bending. Therefore shear wall is one of the most efficient method to

ensuring the lateral stability of the building structure. The use of the reinforced concrete

shear wall has become one of the most efficient method to ensuring the lateral stablity of

a tall building. (Marsono and Subedi, 2000).

Reinforcement detailing of the shear wall are relatively straight forward and easily

implemented at the construction site. Shear wall are also efficient in term of both cost and

effectiveness in minimizing the structural and non-structural element due to the

earthquake damage. Shear wall provide huge strength and stiffness to the building which

reduce the structural damage.

2.4 APPLICATION OF SHEAR WALL

Normally shear wall is constructed for the high rise building like apartment,

commercial tower and also the office tower as the structural wall system to resist the

vertical and also the lateral load. Shear wall are more effective when construct along

exterior perimeter of the building. Other than that, the shear wall is more prefer if build

symmetrical in-plan layout to reduce the ill-effect of twist in building. Figure 2.2 show

the shear wall layout.

11

Figure 2.2: Shear wall layout

2.5 SLENDERNESS RATIO OF SHEAR WALL

According to Euro code 6, the slenderness ratio of the wall is ratio of effective

height to the effective thickness and should not be greater than 27 for walls subjected to

mainly vertical loading. Note also that the effects of creep may be ignored in walls with

a slenderness ratio up to 27.

According to ACI 318 Chapter 10’s requirements for slender compression

members, minimum wall thickness was 6 inches. A height-to-thickness ratio limitation of

25 was imposed on bearing walls, and 30 for non-bearing walls. Such height-to-thickness

ratios increased to 36 when second-order effects were accounted for in the wall panel

design.

12

2.5.1 Slender wall

Walls with aspect ratios of approximately three or greater can be classified as

‘slender’ walls that are controlled by flexural demands. (Moehle et al. 2012) Slender walls

(hw/lw≥ 2.0) tend to behave much like flexural cantilevers. The preferred inelastic

behaviour mode of slender walls is ductile flexural yielding, without shear failure. Shear

yielding of slender walls generally is considered unacceptable because it reduces

inelastic deformation capacity below expected values.

2.5.2 Squat wall

Squat wall is having low aspect ratio and tends to have high inherent flexural

strength compared to shear strength. Squat wall also tends to resist lateral forces through

a diagonal strut mechanism that differ considerably form the flexural mechanism of a

slender wall.

(Moehle et al. 2012) Walls with very low aspect ratios (hw/lw≤ 0.5) tend to resist

lateral forces through a diagonal strut mechanism in which concrete and distributed

horizontal and vertical reinforcement resist shear. Shear yielding of very squat walls is

often accepted because such walls tend to have high inherent strength and low ductility

demands.

2.6 REINFORCING BAR

Shear wall should have the reinforcement in the both longitudinal and transverse

direction in the plane of the shear wall. Other than that, the reinforcement ratio must be

at least 0.0025 of the gross area in each of the direction so that the reinforcement

distributed uniformly across the cross section of the shear wall. This help to control the

width of inclined crack caused by shear. The maximum spacing in each direction must be

less than smaller of Lw/5, 3Tw, and 450mm.

13

(Gaynor, P.J. 1988) concluded that providing ample space between formwork and

reinforcement is recommended to improve shortcrete consolidation, particularly for trim

steel around openings. One curtain of reinforcement is also recommended for shortcrete

construction.

2.7 SOLID 65 ELEMENT

SOLID65 is used for the three-dimensional modelling of solids with or without

reinforcing bars. The solid is capable of cracking in tension and crushing in compression.

The element is defined by eight nodes having three degrees of freedom at each node:

translations in the nodal x, y, and z directions. Up to three different rebar specifications

may be defined. The Figure 2.3 is denoted from (Pooja Hegde 2014).

Figure 2.3: Geometry of Solid 65

Source: Pooja Hegde 2014

2.8 LINK 8

LINK 8 is a spar that can be used in a variety of engineering applications. This

element can be used to model trusses, sagging cables, links, springs, etc. This 3-D spar

element is a uniaxial tension-compression element with three degrees of freedom at each

14

node, translations in the nodal x, y, and z directions. Figure 2.4 is denoted from (Pooja

Hegde 2014).

Figure 2.4: Link 8

Source: Pooja Hegde 2014

2.9 EFFECT OF SIZE OPENING TO PERFORMANCE OF SHEAR WALL

Study conducted by Pooja Hegde and Dr.SV Itti on the “Effect of base opening in

reinforced concrete shear wall” concluded that the shear wall without opening shows that

the load carrying capacity is higher than that shear wall with opening.

Gaynor, P.J. BSCE, 1988 study the “Effect of opening on the cyclic behavior of

reinforced concrete infilled shear wall” concluded that the behaviour of the shear wall

with opening is governed by the aspect ratio of the system, and effect of the size of an

opening was reflected in the strength of the system.

Musmar, A. M. (2013) study the “Analysis of shear wall with opening using

solid65 element” concluded that the stress flow disturbance within the shear wall will

show larger result if the size of the opening is larger. The initial cracking will occur at the

joint between the upper lintel of the opening and edge of the wall when the opening is

tan hock hee

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