Length of Cohesive Zone

[marcus.stephan.schulze]

Hello, 

How does the length of the cohesive zone evolve over crack extension, does it extend until a steady state regime is attained? And how is this done for all increments of crack extension in the code?

Kind Regards, 

Marcus 

[Lukasz Kaczmraczyk]

Hello,

It is not explicit. At the crack tip, cohesive forces are applied. The magnitude of force if the function of the gap, crack opening. If the magnitude is large enough, those forces are zero, or approaches zero, when the linear/bi-linear model or exponential model is applied. 

Regards,

Lukasz

[marcus.stephan.schulze]

hi, 

But is there not a critical crack opening where the forces are taken as zero - even if the exponential model only approaches zero? 

Regards, 

Marcus 

[Lukasz Kaczmraczyk]

In linear model can be ealy calculated:

Gf = (1/2) * ft * w

so if you know ft, and Gf, you can calculate w, which is opening.

[marcus.stephan.schulze]

what is used in the analysis I am running?