Bending Moment in a Beam Experiment

The Bending Moment Moment In A Beam Experiment Experiment

Introduction

This guide describes how to set up and perform Bending Moment in a Beam experiments. From this experiment will clearly demonstrates the principals involved and gives practical support to our studies.

Description

The bending moment in a Beam experiment is shown in figure 1.It consists of a beam, which is cut! by a pivot. To To stop the beam collapsing a moment arm bridges the cut onto a load cell thus reacting "and measuring# the bending moment force. The force from the load cell is shown in a digital display. The beam geometry and hanger positions are shown on the left$hand support of the beam in the diagram. %anger supports are &' mm apart, and have a center slot, which positions the hangers. The moment arm is 1&( mm long.

Figure 1 The bending moment in a Beam experiment

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The Bending Moment In A Beam Experiment

Apparatus

How to set up the equipment

First of all, we set up the apparatus before the experiment. But we need to pay attention on several precaution, we need to always 1. Inspect electrical leads, for damage or wear &. Ma)e sure that the electrical connection are correct *. +hec) the fastening and ma)e sure that all the components are good in condition and setup properly. . -ut the test frame in proper position.  rigid, level surface that easily available is stand by the test frame carefully. -lease be caution that excessive load is prohibit on the e/uipment.

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0e may already complete the instruction from steps 1 to . 1. Test frame that assemble before is place on a wor)bench. Before this the window of the test frame must be easily available. &. efer to the figure *, slide the four securing nuts on the top member of the frame to approximately position. *. Fit the left hand support to the top member of the frame by the right hand end of the resting on the bottom member of the test frame. Ma)e sure that the internal bars are sitting on the frame s/uarely with push the support on the frame. . -ut the remaining two thumbscrews into securing nuts and lift the right hand support into position. 2nsure that the internal bars are sitting on the frame s/uarely by push the support on to the frame. The rolling pivot is middle of its travel because the support position hori3ontally. The thumbscrews are tightening. (. The 4igital Force 4isplay is chec)ed, ma)e sure that 5on6 is display. Mini 4I7 lead from Force Input 1! on the 4igital Force 4isplay is connecting to the soc)et mar)ed Force 8utput! on the left$hand support of the experiment. The beam must not touch the lead. 9. Force meter located on the left hand beam of the experiment is ad:usted to 3ero carefully by using dial. +entre of the beam is applied carefully with a small /uantity of load with a finger. The meter is ad:usted to 3ero again if that is necessarily. Note;
Experiment Experiment 1: Bending oment !ariation at the "oint o# $oading

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This experiment examines how bending moment varies at the point of loading. The force diagram for the beam is shown at figure * below.

This experiment will use the following e/uation;

( l −a ) BM "at cut# = Wa

l

The following table is useful in converting the masses used in the experiment to loads. ass %&rams' $oad %Newton(s' 1'' '.>? &'' 1.>9 *'' &.> '' *.>& ('' .>' Tab)e 1: &rams to Newton(s con*ersion tab)e

"rocedure

1# ead 3ero with no load by chec)ing the 4igital 4isplay meter. &#  hanger with mass 1'' g is placed at the 5cut6. *# The length from a to b is 'mm while the length from a to cut is &9'mm.

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# The 4igital Force 4isplay reading is recorded in Table 1. (# epeat the experiment by using different masses; &''g, *''g, ''g, and (''g. 9# The mass is converted into a load "in 7# and the force reading into bending moment "7m#. Bending moment at the cut "in 7m# = 4isplayed forced x '.1&( @# The theoretical bending moment at the cut is calculate and complete in Table &.

Experiment +: Bending oment !ariation awa, #rom the "oint o# $oading

The cut position of the beam for various loading conditions varies with bending moment.

 statement is used in this experiment; 5lgebraic sum of the moments caused by the forces acting to the left or right of the cut e/ual to the bending moment at the cut!.6

Before this, ensure that is 3ero force display on 4igital Force 4isplay Meter. The beam with the hangers in the position shown in figure is load carefully by using load indicate in the table. esult shown in 4igital Force 4isplay is record down in a table. Bending Moment is converting from the force reading by using the formula as below; Bending moment at the cut "in 7m# = 4isplayed force x '.1&( Aupport reaction " R and RB# must involve in the calculation for the theoretical bending moment at the cut.
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-esu)t

Mass "g# ' 1'' &'' *'' '' (''

2xperimental ?1' '.9''' '.'@(' 1.>9&' 1.1''' '.1*@( &.>*' 1.?''' '.&&(' *.>&' &.*''' '.&?@( .>'(' *.'''' '.*@(' Tab)e +: -esu)t #or experiment 1

Theoretical bending moment "7m# ' '.'1* '.?'&9 1.&'*> 1.9'(* &.''99

raph Bet!een Experimenta" Mending Moment and Theoreti#a" Bending Moment 2.5 2

2

2.01 1.61

1.5

Bending Moment %&m'

1.2

11 0.8 0.5

00

0.4 0.08

0.14

0.23

0.29

0.38

Ma(( Experimenta" $ending moment %&m'

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Theoreti#a" $ending moment %&m'


Figure

01 "7#

 ( 9

1.>9&' '.>?1' *.>&'

0& "7#

Force "7#

2xperimental Bending Moment "7m#

&.> &.>

$'.9''' &.&''' &.(

$'.'@(' '.&@(' '.*1&(

 "7#

B "7#

&.(?*9 1.9>&@ &.'>1

$'.9&*9 &.&&@* .?1'>

Theoretical Bending Moment "7m# $'.'?@@ '.*11? '.9@*(

Tab)e .: -esu)t #or experiment +

Discussion

The factor of errors that may have caused the large percentage between the measured moment from the experiment and theoretical moment are as follow; %uman error %uman error too) place during experimenting such as load error, which might have contributed to the discrepancies in the final results.
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The comparisons between the experimental bending moment and the theoretical bending moment for a beam under various loads are as follow; 2xample for 1''g, verage experimental bending moment = '.'@('7m Theoretical bending moment = '.'1*7m -ercentage 4ifference = ?1.*1

-e#erences

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Bending Moment in a Beam Experiment

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