Shear Stress Deflection 2

[Wbruseski]

Does anyone have any references on calculating deflection due to shear stress? I am looking for deflection due to uniform load, simply supported beam for a sandwich panel (aluminum skins with EPS core). Thanks for any input.

 

[Mattman]

An old reference of mine, Ketchum's Structural Engineer's Handbook, give the following for elastic deformation due to shear(L= length subjected to shear, G=shear modulus, A=cross sectional area of member):

Delta= (P*L)/(A*G)

 

[steve1]

Blodgett's "Design of Welded Structures" has a chapter devoted to shear deflection. According to Blodgett, "normally deflection due to shear in the usual beam is ignored because it represents a very small percentage of the entire deflection, .....deflection due to shear increases linearly as the length of the beam increases, whereas the deflection due to bending increases very rapidly as a third power of the length of the beam".
Hope this helps.

 

[dougantholz]

Am I missing something, or is the deflection of a member (from the Virtual Work Method)

delta = integral (M*m/E*I) dx + integral (V*v/G*A')dx + sumation (NnL/AE)

where M, V and N are the internal stresses due to the real, exteranally appiled loads
& m,v,n are the internal stresses due to the stress caused by the virtual load.
A' is the shear area
A is the cross-sectional area
L is the length
E is the modulas of elasticity
G is the shear modulas

delta is the deflection times the unit load applied

 

[Wbruseski]

Yes, dougantholz your answer is what I was looking for but I was also looking for a reference. I found it in my Roark's "Formulas for Stress and Strain". Thanks.
Also, steve1 shear stress is not insignificant in this case because of the EPS foam core which has a very low G (shear modulus). And, Mattman, you're right except missing some factors which change for loading type, end conditions, and cross section of the member. Just some info. Thanks again.