© D.J.DUNN1MECHANICS OF SOLIDS -BEAMSTUTORIAL 3THE DEFLECTION OF BEAMSThis  is  the  third  tutorial  on  the  bending  of  beams. You  should  judge  your progress by completing the self assessment exercises. On  completion  of  this  tutorial  you  should  be  able  to solve the  slope  and deflection of the following types of beams.A cantilever beam with a point load at the end.A cantilever beam with a uniformly distributed load.A  simply  supported  beam  with  a  point  load  at  the middle.A  simply  supported  beam  with  a  uniformly  distributed load.You will also learn and apply Macaulay’s method to the solution for beams with a combination of loads.Those  who  require  more  advanced  studies  may  also apply Macaulay’s method to the solution of ENCASTRÉ.It  is  assumed  that  students  doing  this  tutorial  already know  how  tofind the  bending  moment  in  various  types  of  beams.This  information  is contained in tutorial 2.
© D.J.DUNN2DEFLECTION OF BEAMS1. GENERAL THEORYWhen  a  beam  bends  it  takes  up  various  shapes  such  as  that illustrated infigure  1. The shape may be superimposed on an x –y graph with the origin at the left end of the beam (before  it  is  loaded).  At  any  distance  x  metres  from  the  left  end,  the  beam  will  have  a deflection y and a gradient or slope dy/dx and it is these that we are concerned with in this tutorial.We  have  already  examined  the  equation  relating  bending  moment  and  radius  of curvature in a beam, namely     REIMM is the bending moment.I is the second moment of area about the centroid.E is the modulus of elasticity andR is the radius of curvature.Rearranging we have EIMR1Figure 1 illustrates the radius of curvature which is defined as the radius of a circle that has a tangent the same as the point on the x-y graph. Figure 1Mathematically  it  can  be  shown  that  any  curve  plotted  on  x -y  graph  has  a  radius  of curvature of defined as 2322dxdy1dxydR1