Wednesday, 21 December 2022

Beam Deflection

 Beam Deflection

 In numerous cases of structural and machine designs, members must repel the force applied indirectly or obliquely to their axes. similar members are called shafts. The main members supporting the bottoms of structures are shafts, just as an axle of an auto is a ray. numerous shafts act contemporaneously as torsion members and as shafts. So far it can be said ray is an integral part of the construction.

 Beam Deflection

 Beam deviation means the state of distortion of a ray from its original shape under the work of a force or cargo or weight. One of the most important operations of ray deviation is to gain equations with which we can determine the accurate values of ray diversions in numerous practical cases. diversions are also used in the analysis of statically indeterminate shafts.

 Styles to Determine Beam Deflection

 Several styles are available for determining ray diversions. The principle is the same but differs in fashion and in their immediate ideal.

1.       Direct Integration system

2.      Area Moment Method

3.      Conjugate Beam Method

4.      system of Superposition

 Direct Integration Method

 Beam diversions due to bending are determined from distortion taking place along a span. This is grounded on the thesis that during bending, aeroplane sections through a ray remain plain. For now, it'll be assumed that bending takes place only at about one of the top axes of the sampling. The edge view of the neutral face of a veered ray is called the elastic wind of the ray. The discrimination equation of the elastic wind of a ray

EId2ydx2=MEId2ydx2=M

The product EI is called the flexural rigidity of the beam which is usually constant along the beam.

v = deflections of the elastic curve

θ = dv/dx = v' = slope of the elastic curve

M=EId2vdx2=EIv′′M=EId2vdx2=EIv′′

V=dMdx=ddx(EId2vdx2)=(EIv′′)V=dMdx=ddx(EId2vdx2)=(EIv′′)′

q=dVdx=d2dx2(EId2vdx2)=(EIv′′)′′q=dVdx=d2dx2(EId2vdx2)=(EIv′′)′′

By simplifying-

EId2vdx2=M(x)EId2vdx2=M(x)

EId3vdx3=V(x)EId3vdx3=V(x)

EId4vdx4=q(x)EId4vdx4=q(x)

Here q(x) is the load function. The choice of which equation we will use to determine v depends on the ease with which an expression for moment, shear or load can be formulated.

Some Boundary Conditions:

  1. Clamped or fixed support:
     

  2. Roller or pinned support:
    In this case. the end is free to rotate, that’s why the moment is zero.

 


  1. Free end:

 


  1. Guided Support:

 


 

Er. SP. ASWINPALANIAPPAN., M.E., (Strut/.,)., (Ph.D.,)

Structural Engineer

http://civilbaselife.blogspot.com

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