Bending_Moment_Variation_for_Various_Loading_Conditions[1].docx

7/28/2019 Bending_Moment_Variation_for_Various_Loading_Conditions[1].docx

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CC205~MECHANIC OF STRUCTURE

JKA, POLITEKNIK SULTAN ABDUL HALIM MUADZAM SHAH

EXPERIMENT 2(B)

TITLE : Bending Moment Variation for Various Loading Conditions

OBJECTIVES : This experiment examines how bending moment varies at the cut position of the

beam for various loading conditions.

INTRODUCTION :

*Bending Moment

In a similar manner it can that if the Bending moments (BM) of the forces to the left of AA are

clockwise then the bending moment of the forces to the right of AA must be anticlockwise.

Bending Moment at AA is defined as the algebraic sum of the moments about the section of all

forces acting on either side of the section

Bending moments are considered positive when the moment on the left portion is clockwise and on

the right anticlockwise. This is referred to as aging bending moment as it tends to make the beam

concave upwards at AA. A negative bending moment is termed hogging.
http://www.codecogs.com/users/23287/SF-and-BM-0002.png


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APPARATUS :

1) Digital Force Display

2) Load and Hanger

3) Rules


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THEORY :

We know that if a body or object of any sort is stationary, then the forces on it balance, as follows:

(1) Vertical equilibrium (total force up = total force down)

(2) Horizontal equilibrium (total force right = total force left)

(3) Moment equilibrium (total clockwise moment = total anticlockwise moment).

We will use the statement:

The Bending Moment at the cut is equal to the algebraic sum of the moments caused by the forces

acting to the left or right of the cut.


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PROCEDUR:

(i) Check the Digital Force Display meter reads zero with no load.

(ii)Measure the first position

.


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(iii) Carefully load the beam with the hangers in the positions shown in Figure 1, using the loads

indicated in table 2a.

cut

140mm 300mm

W1 RA RB

W1 = 3.92 N (400g)

Figure 1 : Force diagram

(iii) Record the Digital Force Display reading as in a figure 2 and figure 3.

(iv) Repeat the procedure with the beam loaded as in figure

(v) Convert the mass into a load (in Nrefer table 1a)

140mm cut

RA 260mm RB

W1 W2

W1 = 1.96 N (200g)

W2 = 3.92 N (400g)


240mm cut

400mm

RA W1 W2 RB

W1 = 4.91 N (500g)

W2 = 3.92 N (400g)



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Result :

Figure W1 (N) W2 (N) Experimental

bending moment

(Nm)

RA (N) RB (N) Theoretical

bending moment

(Nm)

1

2

3

CALCULATION :

Calculation for Theoretical bending moment (Nm)

W : Load (N), a : the distance to the load (not the cut) (m)-3

Load 3.92 ()( )

Load 5.88

Load 8.83

Calculation for RA and RB :

Figure 1 :

Figure 2 :

Figure 3 :

DISCUSSION :


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1. Comment on how the result of the experiments compare with those calculated using the theory.

CONCLUSION :

REFERENCE :

Documents

Bending_Moment_Variation_for_Various_Loading_Conditions[1].docx