INFO G(II) TOUGHENING EFFECT

[LUIGI74]

WHEN I DO END NOTCHED FLEXURAL TEST ON COMPOSITES LAMINATES I MUST DETERMINE THE G(II) [RELEASED ENERGY]. I USE THIS EQUATION:
G=(9*P^2*a^2)/(16*E*H^3*B^2)
WITH "a" CRACK DIMENSION.
WITH THE TOUGHENED EPOXY RESIN I MUST FIND THE G(II) GREATER THAN UNFILLED RESIN?
a SECOND QUESTION IN THE EQUATION THE "E" VALUE THAT I MUST INSERT IS THE "E" VALUE OF THE UNIDIRECTIONAL 0° MODULUS OF THE LAMINATE WITHOUT CRACK, OR IT IS THE MODULUS OF EVERY SINGLE TEST (SO IT CHANGE ON EVERY TEST BECAUSE IT DEPEND BY THE DIMENSION OF THE CRACK)?
THANK YOU IN ADVANCED FOR THE ANSWER.

LUIGI74

 

[Bumblebee2000]

I'm not a composites expert but, I'm interested in helping you with your problem. What does the P, H, and a represent in your equation? What is your equation based on? I'm sure the equation is dependent on the type of composite you are using; orthotropic, anisotropic, etc.?

There are some other issues you may want to address also.

Please contact me at:

bawatson@raytheon.com and/or bahiy_a_watson@yahoo.com