can stiffness be written as a function of Thickness

[sfhaider]

Guys, How can stiffness be written as a function of Thickness
K = A0 + A1 * T + A2 * T^3
Any ideas, my brain is not working

 

[EngAddict]

Stiffness is a function of applied load and deflection. You might be able to argue that if the thickness is great enough then the deflection will go to zero, giving a rigid structure.

Depending on your loading you may be able to define the deflection then calculate an equivalent stifness.. E.g. deflection at the centre of a simply supported beam with a point load @ centre is:

s=Wl^3/48EI

k=W/s

Simplify and let your height 'h' in the second moment of area equal the thickness, 't'.

k=4Ebt^3/l^3

This is stiffness as a function of thickness and is also the formula for the stiffness of a single layer leaf spring (i.e. simply supported beam, loaded at the centre).

So in answer to your question there is no general rule but it would depend on the structure and your method of loading.