1.0 OBJECTIVE1.1 To examine how shear force varies with an increasing point load.1.2 To examine how shear force varies at the cut position of the beam for various loading condition.

2.0 LEARNING OUTCOME2.1 The application the engineering knowledge in practical application.2.2 To enhance technical competency in structural engineering through laboratory application.2.3 To communicate effectively in group.2.4 To identify problem, solving and finding out appropriate solution through laboratory application.

3.0 THEORYPart 1 :

Figure 1

Shear force at the left of the section, ............... equation 1

Shear force at the right of the cut section , ............... equation 2Part 2 :

Use this statement :The shear force at the cut is equal to the algebraic sum of the force acting to the left or right of the cut.4.0 APPARATUS

Structure Equipment

Digital Force Display

Structure Test Beam

5.0 PROCEDUREPart 1 :i. Digital Force Display meter reads zero with no load is checking.ii. Hanger with a 100g mass was placed to the left of the cut.iii. The Digital Force Display reading was recorded in Table 1.Shear Force at the cut (N) = Displayed Force.The step was repeated with any mass range between 200g to 500g. The mass was converted in a load in Newton (multiply by 9.81)iv. The theoretical Shear Force at the cut was calculated and the Table 1 also completed.

Part 2 :i. Digital Force Display meter reads zero with no load is checking.ii. Three load hangers with 100g 500g mass respectively placed at any position between the supports (as example in Figure 2, Figure 3, and Figure 4).iii. The digital force display reading was recorded in Table 2 where :Shear Force at the cut (N) = Display Forceiv. The support reaction (RA and RB) was calculated and the theoretical Shear Force at the cut was calculated too.

Figure 2

Figure 3

Figure 4

6.0 RESULT

Mass (g)Load (N)Force (N)Experimental Shear Force (N)Theoretical Shear Force (N)

00000

1000.9810.50.50.446

2001.9621.01.00.892

3002.9431.51.51.338

4003.9242.02.01.784

5004.9052.52.52.230

Table 1

NoW1 (N)W2 (N)Force (N)Experimental Shear Force (N)RA (N)RB (N)Theoretical Shear Force (N)

11.9620-0.6-0.62.586-0.6241.488

21.9621.9622.02.01.7842.1401.784

31.9621.9620.70.71.1592.765-0.803

Table 2

7.0 CALCULATION7.1 Part 1 : For mass = 100g

Load = Mass 9.81

= (100/1000) 9.81= 0.981N

Theoretical Shear Force,

0.446NFor mass = 200g

Load = Mass 9.81

= (200/1000) 9.81= 1.962N

Theoretical Shear Force,

0.892N

For mass = 300g

Load = Mass 9.81

= (300/1000) 9.81= 12.943N

Theoretical Shear Force,

1.338N

For mass = 400g

Load = Mass 9.81

= (400/1000) 9.81= 3.924N

Theoretical Shear Force,

1.784N

For mass = 500g

Load = Mass 9.81

= (500/1000) 9.81= 4.905N

Theoretical Shear Force,

2.230N

7.2 Part 2 :For Figure 2 :

Mass = 200g

W1 = Mass 9.81

= (200/1000) 9.81= 1.962N

MB = 0RA (440) = (1.962)(440 + 140)RA= 2.586N

FY = 0RA + RB W1 = 02.586 + RB 1.962 = 0RB = -0.624N

Theoretical Shear Force,

1.488N

For Figure 3 :

Mass = 200g

W1 = Mass 9.81

= (200/1000) 9.81= 1.962N

MA = 0RB (440) 1.962(260) 1.962(220) = 0RB= 2.140N

FY= 0RA + RB W1 W2 = 0RA + 2.140 1.962 1.962= 0RA = 1.784N

Theoretical Shear Force,

1.784N

For Figure 4 :

Mass = 200g

W1 = Mass 9.81

= (200/1000) 9.81= 1.962N

MA = 0RB (440) 1.962(400) 1.962(220) = 0RB= 2.765N

FY= 0RA + RB W1 W2 = 0RA + 2.765 1.962 1.962= 0RA = 1.159N

Theoretical Shear Force,

= = -0.803N

8.0 DISCUSSION8.1 Part 1 :i. Derive equation 1

Shear Force at left of the section, MB = 0RA.L W.(L a) = 0

RA =

ii. Plot a graph, which compare your experimental result to those you calculated using theory.

iii. Comment on the shape of the graph. What does it tell you about how Shear Force varies due to an increased load?From the graph that has been plotted, it can conclude that the both of the graph are positive linear graph. Its shown that the increasing of shear force is depends on the increasing of loads. When the loads increase, the shear force will increase too. So, it shows that the increasing of loads will affected the increasing of shear force.

iv. Does the equation you used accurately predict the behaviours of the beam?Yes. This equation that we used accurately predicts the behaviours of the beam. It shows that the result of experimental value only have a small different if compare to theoretical shear force. The experimental result is higher that the theoretical result.

8.2 Part 2i. Comment on how the results of the experiments compare with those calculated using the theory.From the calculation, the experimental result and theoretical result shows a totally different result. For Figure 2, the theoretical value is bigger than the experimental value. But for Figure 3 and Figure 4, the experimental value of shear force is much smaller than the theoretical value. This may be happened due to some errors such as this sensitive apparatus easily affected by surrounding. However, errors can be eliminating by repeated test at least few times in order to gain average readings.

ii. Does the experiment proof that the shear force at the cut is equal to the algebraic sum of the force acting to the left or right of the cut. If not, why?Yes, the shear force at the cut is equal to the algebraic sum of the force acting to the left or right of the cut. The shear force can be calculate based on data distance. Proof by our experiment, distance effect the shear force.

iii. Plot the shear force diagram for load cases in Figure 2, Figure 3 and Figure 4.Refer to next page

iv. Comment on the shape of the graph. What does it tell you about how Shear Force varies due to various loading condition?We know that the increasing of load will affect the shear force. When the large load applied, the shear force will increase. But, in this test, we use the same load at this experiment which is 1.962N. From the graph, we can know that the shear force will increase at the cut section.

9.0 CONCLUSIONPart 1 :From the experiment, it shows that the value of experimental shear force only have small different with the value of theoretical shear force. From the calculated value, we know that the increasing shear force will affected the increasing of shear force.

Part 2 :From this experiment, we know that the result of theoretical and experimental value is totally different. Most of the experimental result is higher than the theoretical value. The indicated that there were some errors occur during the experiment: i. The readings maybe were affected by the surrounding environment becausethe digital force display is very sensitive. ii. This error also may caused by rounded error or significant error. Shear force is the force in the beam acting perpendicular to its longitudinal (x) axis. For design purposes, the beam's ability to resist shear force is more important than its ability to resist an axial force. Axial force is the force in the beam acting parallel to the longitudinal axis.

Normally a beam is analyzed to obtain the maximum stress and this is compared to the material strength to determine the design safety margin. It is also normally required to calculate the deflection on the beam under a maximum expected load. The determination of the maximum stress results from producing the Shear Force Diagram and Bending Moment Diagram. To facilitate this work, the first stage is normally to determine all of the external loads.

From this experiment, shear force varies with an increasing point load was proven. The objectives of the experiment were achieved.

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