rubber specification

[JP123]

Hi, those anyone knows the following coefficients for EPDM rubber expansion joint PROCO style 233:
- Poisson's ratio
- Young modulus
- Transaxial compression
- Expansion coefficient
- Effective surface

We need those coefficient for finite element calculation and be sure it will resist to piping movement and the media which is water at 95 deg C (worst case).

Thank you for any help or references

 

[GrahamBennett]

JP123, I've asked the head of our engineering unit for some numbers for you. His response is:

Poisson's ratio depends mainly on the bulk modulus and slightly on the Youngs modulus at very low strains for the subject compound. If the Youngs modulus lies between 0.92 and 9.40MN/m², Poisson's ratio lies between 0.49930 and 0.49993.

Youngs modulus can be estimated from the hardness of the subject compound. IRHD = 30, YM = 0.92MN/m², IRHD = 70, YM = 9.40MN/m². The estimation is roughly a straight line correlation.

The expansion coefficient depends on the formulation used and is roughly the same as other rubber polymers.

We do not know what you mean by transaxial compression and effective surface.

 

[JP123]

thank you for these answers, it will be very helpful.

since the expansion joint is corrugated, the diameter is bigger and the effective area include those corrugated things.

the transaxial compression is the perpendicular force pushing on the side of the expansion joint that it can handle

Am I clear?

Thank you.

 

[n1nj4i]

hi,

how about general value for EPDM rubber that usually use for weather strip in cars?

- Poisson's ratio
- Young modulus
- Transaxial compression
- Expansion coefficient
- Effective surface
- density

 

[GrahamBennett]

N1 - I refer you to my original post for Poisson's ratio and Young's modulus. Effective surface is obtained from the drawing of the part. Expansion coefficient varies according to the amount of blow, as does the density but both can be measured relatively easily.

 

[n1nj4i]

right!

thanks for that.