CES511 –STRUCTURAL ENGINEERING LABORATORY

downloaded from

Scholarfriends

https://scholarfriends.com

Downloaded by: browsegrades@gmail.com | https://scholarfriends.com/singlePaper/187447/ces511-structural-engineering-laboratory Distribution of this document is illegal.

CES511 –STRUCTURAL ENGINEERING LABORATORY LAB EXPERIMENT: INDETERMINATE BEAM (CO2:PO5) SEMESTER GROUP LECTURER

: : :

OCT - FEB 2021

DATE OF LAB : LAB LEVEL OEL : 1

CO2: Organize laboratory work on structural elements and materials.

PO5: Ability to utilize appropriate techniques, resources and modern engineering and IT tools in predicting and modelling of complex civil engineering problems with an understanding of the limitations.

NO

STUDENT ID

NAME

1

1.

2

CRITERIA 3 4

TOTAL

2.

3.

4.

5.

PSYCHOMOTOR PERFORMANCE RUBRIC NO.

PERFORMANCE SCALE

CRITERIA

Developing 0

1

2

Ability to design and conducted a research- based experiment (P1-P2)

Successfully performs experiment without guidance based on level of Openness (P3-P4)

3

Ability to manipulate the data leading to findings (P5-P6)

4

Ability to adapt the obtained result with logical justification (P5-P6)

1

Functional

Proficient

2

3

Advanced 4

Often requires instructor to design / identify basic idea / task of the experiment.

Generally able to design / identify basic idea / task of the experiment.

Helps are required to conduct the whole experiment.

Helps are required with refinement in several major details and conduct the experiment.

Able to conduct the experiment with minimal guide from the instructor.

Able to conduct a research-based experiment.

Cannot complete tasks and standard procedures.

Low ability to complete tasks and standard procedures.

Successfully complete experiment procedures with moderate supervision.

Successfully complete experiment procedures with minimal supervision.

Successfully complete experiment independently.

Incorrect interpretation of trends and comparison of data indicating a lack of understanding of results.

Incomplete interpretation of trends and comparison of data indicating a lack of understanding of results.

Minimal with 1 sentence describing the main finding of the experiment.

Almost all of the results have been correctly interpreted but without sufficient support of important trends or data comparisons.

All of the results have been correctly interpreted, with only 1 sufficient support of important trends or data comparisons.

Failed to show any idea at all

No ability to adapt the result with any suitable justification.

Show effort to give reasonable justification but incorrect

Display effort to understand the finding with major flawed interpretation

Display effort to understand the finding with minimum flawed interpretation

Unable to design/ identify the basic idea / task of the experiment.

Helps are required to conduct the whole experiment.

Has a very low ability to design/ identify the basic idea / task of the experiment.

Instruction to Students 1. Two (2) weeks duration is given for each lab report submission.

2. Any plagiarism found or not properly cited, the group will be penalized and marks will be deducted.

Independently designed / identified idea / task of the experiment.

5 Independently designed / identified the idea / task of the experiment with additional supporting references.

Show an outstanding ability in conducting research-based experiment.

Successfully complete experiment independently.

All of the results have been interpreted correctly, with sufficient support of important trends or data comparisons Show excellent understanding between the results to adapt with logical justification

Lab Report: CES511 – STRUCTURAL ENGINEERING LABORATORY

UNIVERSITI TEKNOLOGI MARA KAMPUS PULAU PINANG

TABLE OF CONTENTS

NO.

TITLE

PAGES

1

1.0 Introduction

2

2

2.0 Problem Statement

2

3

3.0 Objectives

2

4

4.0 Apparatus

2-3

5

5.0 Procedure

4

6.0 Data and Analysis 6

6.1 Table Data and Analysis

5

6.2 Graph Support A and B

6

6.3 Sample Calculation

7-8

7

7.0 Discussion

9 - 10

8

8.0 Conclusion

10

1

1.0 INTRODUCTION The redundant in form of reaction exist in an indeterminate system. However, static equation itself unable to solve that particular redundant. The superposition method is one of the suitable approaches to determine this reaction. The fixed end moment of a fixed end beam is given by; MFAB = -W * a * b² / L² MFBA = -W * a² * b/L² 2.0 PROBLEM STATEMENTS Structural could be classified into statically determinate and indeterminate system. Static equation can be used to solve the determinate problem. Meanwhile, superposition method can be used to solve the indeterminate problem.

3.0 OBJECTIVE To validate the theoretical equation of fixed end moment of indeterminate beam through experimental work by using the superposition method for indeterminate beam.

4.0 APPARATUS 1. Support A and B (fixed support both)

Support A

Support B

2. Beam (1m)

2

3. Load hanger (Reaction A and B)

Reaction A

Reaction B

4. Load hanger (Point load)

5. Load

3

5.0 PROCEDURE 1. Fixed length support A and B into 1m. Locked the support at bottom.

2. Placed beam at support. Make sure in straight condition. Used screw at supports to lock.

3. Put the load hanger as point load 0.2 m from support A. 4. Locked the supports.

5. Loosed screw at both support before applied load.

6. Applied load 4N at point load hanger.

7. Applied 2N load as reaction at blue hanger simultaneously. Logically, when applied load at center of the beam, the reaction both side will be same. But in this case the applied load is not at center.

8. Check the reading both dial gauges is zero to know the value correct. Applied another load when the reading at dial gauges still not zero at both side simultaneously.

9. When one side of support becomes zero, stop applied load at both reactions.

10. Applied load at yellow hanger at which support that not to zero. It was for counter back that applied in blue hanger.

11. Took weight load when reach zero as reaction. The data had been recorded.

12. Repeated step 6 to 11 in order to increasing the load applied.

13. Analyzed the data.

4

6.0 DATA AND ANALYSIS Beam span

= 1.0 m

Distance of load from support A = 0.2 m P

0.8 m (b)

0.2 m (a)

1.0 m (L) 6.1 TABLE DATA AND ANALYSIS Load (N)

Reaction A (N)

Reaction B (N)

4

0.8

3.2

8

1.6

6.4

12

2.4

9.6

16

3.2

12.8

20

4.0

16.0

Table 1: Table of reactions support A and B Fixed End Moment At Support A (Nmm) Load on beam

MF (Experimental)

MF (Theoretical)

Fixed End Moment At Support B (Nmm)

MF (Experimental)

MF (Theoretical)

(N) VA * 55

MF AB = - W * a * b2/ L2

VB * 55

MF BA = - W * a2 * b/ L2

4

44

-512

176

-128

8

88

-1024

352

-256

12

132

-1536

528

-384

16

176

-2048

704

-512

20

220

-2560

880

-640

Table 2: Table of data analysis support A and B

5

6.2 GRAPH SUPPORT A AND B Graph support A

Graph of Fixed End Moment versus Load Applied Fixed End Moment, Nmm

3000 2500 2000 1500

Experimental

1000

Theoretical

500 0 4

8

12

16

20

Load Applied, N

Graph 1: Support A Graph support B

Fixed End Moment, MF BA (Nmm)

Graph of Fixed End Moment versus Load Applied 1000 900 800 700 600 500

Theoretical

400

Experimental

300 200 100 0 4

8

12

16

Graph 2: Support B 6

20

6.3 SAMPLE CALCULATION DOI = r – n – c =6–3–0 = 3 … Statically indeterminate 

Support A At load 4N; Experimental, MFAB = VA * 55 = 0.8 * 55 = 44 Nmm Theoretical, MFAB = -W * a * b2/L2 = - (4) * (200) * (800)2 / (1000)2 = -512 Nmm

Experimental Slope = a * b2 / L2 = (200) * (800)2 / (1000)2 = 128

Theoretical Slope = (2560 – 512) / (20 – 4) = 128

Percentage error = (Slope Theory - Slope Experiment) x 100 % Slope Theory = (128 - 128) x 100 % 128 = 0% ⸫ Theoretical slope value = experimental slope value

7



Support B At load 4N; Experimental, MF BA = VB * 55 = 3.2 N * 55 = 176 Nmm Theoretical, MF BA = - W * a2 * b/ L2 = - (4) *(200mm) 2* (800mm) / (1000mm) 2 = -128 Nmm Experimental slope = a2 * b/ L2 =

(200) 2 * (800) / (1000) 2

=

32

Theoretical slope = (640 - 128) / (20 - 4) =

32

Percentage error = (Slope Theory - Slope Experiment) x 100 % Slope Theory = (32 - 32) x 100 % 32 = 0% ⸫ Theoretical slope value = experimental slope value

8

7.0 DISCUSSION Beam is a structural element that preliminary resists load applied laterally to the beam’s axis. The beam can be deflecting by the preliminary bending. Indeterminate beam is occur when the degree of the indeterminacy (DOI) is more than 0 which caused by the unknown force. In this experiment, students used steel specimen represent as beam. The length of the beam is measured by 1m. The distance of load from support is 0.2m. The types on support used were fixed both end support.

Based on the experimental value, it shows that the value of reaction for both support A and B increasing due to the load applied. In this case students said that the reaction value will increase when higher load applied. Besides, students also observed that the value of reaction at support A is lesser than value reaction at support B. It is because of the location load P is nearer to the support A. The nearer load at the support, the lower reaction will obtain.

In this analysis of experimental result, students observed that the fixed end moment at support A was increase while at support B was increase due to the load applied. For the theoretical value, it shows that the fixed end moment at support A was increase while at support B was increase due to the load applied. By comparing this two data about experimental and theoretical, it shows that percentage error at support A was 0% while at support B was 0%. It shows that experiment at support A and B succeed. Based on the graph of analysis, it shows that both graph increasing gradually by fixed end moment at support and the load.

By examined in order to perform the experiment, there are several precaution in order to the get the percentage error nearest to zero percent. Firstly, make sure that the experiment away from the external disturbance such as vibration. Vibration can make the value of reaction increasing or decreasing as the load hanger sway when vibration occurs. Besides, make sure put the load at load hanger simultaneously as it will not make the reading at the other side more than actual. Make sure source of wind such as fan switch off in order to avoid disturb the reading.

In analysis, there are several factors that affecting the experimental reading at dial gauge. Firstly, types and the dimensions of the specimen beam. The higher the flexibility of specimen beam, the higher percentage error will get. Besides, condition of the beam also 9

gives effect to the value of reaction. The bend beam will make the ability of percentage error nearest to zero percent is lower.

8.0 CONCLUSION From the experiment that has been conducted, it can be concluded that when a beam is loaded with a single point, the fixed end moment value is increasing linearly to the load. It is also obvious that the distance of applied load from the support influence the value of fixedend moment of the reaction. Experimental and theoretical bending moment shows perfect linear relationship with applied load but there is a lot of difference in the values of experimental versus theoretical bending moment. It may be due to some error occurring during the experiment. So, the right apparatus and procedures must be aware when doing this experiment to get the best result.

10