shape factor of rubber pad

[Josh2015]

The definition of shape factor is the ratio of load area to the free-bulge area.

But for a complex rubber pad stack which has openess (attached), I am confused with the load area.

Can anyone help me out?

Thanks,

 

[GrahamBennett]

I would contact the Tun Abdul Razak Research Centre (

http://www.tarrc.co.uk)

and ask the rubber engineers there because they developed the mathematics for this.

 

[tomaspin]

Josh

I have attached a little sketch from 'Engineering Design With Natural Rubber' which explains the calculation of shape factor.
From your post it seems that you are dealing with a multi-layer (interleaved) spring.
These are essentially a set of springs in series, so the shape factor is calculated from a single layer. Assuming all the layers are identical, and the calculated stiffness of one layer is K, the the total stiffness is K/N, where N is the number of layers.

Does this help?

Tom