FRP Elastic Modulus definition of input

Posted by: Van Ha

FRP Elastic Modulus definition of input - 12/30/15 03:30 AM

Hi all

I have questions as below:

#1: When selecting material ID 20, parameters "Elasticity Modulus (H1)" -> "Elasticity Modulus (H9)" are Hoop Elasticity Modulus ?

#2: I see some FRP reports, vendor provide only one value of Axial Elasticity Modulus, but some other reports they provide Axial Elasticity Modulus values at different temperatures. What temperature should be referred to input value of Axial Elasticity Modulus ?
Posted by: Dave Diehl

Re: FRP Elastic Modulus definition of input - 01/04/16 11:27 AM

Those Elastic Modulii H1 to H9 are the hot (axial) modulii.
I think the only CAESAR II reference to FRP hoop modulus is in calculating the stress envelop for ISO 14692 bends.
Posted by: Van Ha

Re: FRP Elastic Modulus definition of input - 01/04/16 10:17 PM

Hi Dave,

That means Hoop modulus is not required to input? Will it automatic calculated inside CII?

As I understand base on CII user guide, Hoop modulus is only used to determine piping elongation due to pressure.
Posted by: KimTaeSung

Re: FRP Elastic Modulus definition of input - 01/05/16 01:09 AM

Hi Van Ha,
FRP is orthotropic models. It requires two elasticity modulus : axial and hoop. When i use FRP material, I just input "Ea/Eh*Vh/a". To minimize input, these parameters are combined. It contains hoop modulus.
Posted by: Dave Diehl

Re: FRP Elastic Modulus definition of input - 01/05/16 08:54 AM

Van Ha,

As KimTaeSung says, the hoop modulus is tied in with the Poisson ratio to account for its effect on pressure elongation.
Posted by: Van Ha

Re: FRP Elastic Modulus definition of input - 01/05/16 09:19 AM

Normally, "Ea/Eh*Vh/a" is provided by vendor as a specific value and we just input that value into CII. That's why I want to confirm Hoop Modulus is not really necessary to be known ???