Bending
of
a
Channel
Section

Experiment Two: Stiffness Report from laboratory work performed on 12 May 2011 as a part of the unit of study CIVL2201 Structural Mechanics

Abstract

This report has been written to describe an experiment performed on a channel section examining the stiffness of the beam through two differing types of deformation – curvature and deflection. The aim of the experiment was to determine the value of the flexural rigidity (EI) in two different ways; using the curvature, k, and the mid-span deflection. The testing method used for the experiment is described. The experiment found that the EI values calculated were as follows: - EIcurv = 1.76E+10 Mpa.mm4 when calculated using the curvature, k. - EIdefl …show more content…

The value of EI becomes particularly useful within structural engineering when calculate the stresses and strains in a particular structure due to bending, the curvature at which a structure is bending, the moment force causing the bending and is a major component of the equations used for the calculation of beam deflection. With the EI calculated, it could then be used in various equations to determine the values of Young’s modulus (E) and the second moment of area (I). Young’s modulus provides a direct comparison of stress and strain determining the stiffness of a material through whilst acting in a linear elastic behaviour. The second moment of area for an object is used to give a representation of how the area of an object is distributed with respect to the centroid. Both E and I are important for use within many formulas pertaining to structural engineering.

Test
Method

Diagram
of
the
test
setup

DIAGRAMMATIC REPRESENTATION OF THE TEST SET UP ! L = 2432mm

Figure
1.


,-)..+/'0+1&2$.' a = 467mm

Channel section

!&%)2.'5)"5+')&' *24#0).' Dial Gauge’s 1, 2, & 3 8'

a = 467mm

A

8'

A
3$)42.5'-$$6'7' P 3$)42.5'-$$6': Mid-span 3$)42.5'-$$6';' P

Hook #1

Hook #2

!"##$%&'(%)*+'

Section AA !+1&2$.'898'
! ! EQUIPMENT LIST

22/05/2001

3

! "!#!$%%!&&!'())*!+,*)'!

Bending of a Channel Section

Diagram
of
dial
gauge
setup

Figure
2.


Figure 2 is a photo taken during the experiment to