Hi Kartikeya,

Your question is difficult to answer.

It sounds like you know the debonding force but you want to convert this into an interface strength. I suppose that an interface strength parameter sounds like an interface property and should be expressed in terms of a stress (load over area). Do you know the stress distribution along the interface at the point when the interface breaks? You might use the peak value of that stress distribution as a "bond strength".

Regards,

Simon

Hello sir thank you for your reply

As you see in figure i got load vs displacement curve for a fiber pull out test but in an author paper they plotted against interfacial bond strength that i don't understand. in ansys.

It will be helpful if you suggest. The Equivalent stress value at the time of failure is high and it does not matches with result.

Hi Kartikeya,

I'm still a bit uncertain about the data. Let me make some comments and see if they help. The relate to the attached picture.

• Let's say that there is a stress distribution along the interface between the SMA fibre and the epoxy.
• Let's say that the whole interface fails when the peak value of the stress distribution reaches a critical level (called the "strength").
• Under these circumstances, we are assuming that the peak value of the stress distribution along of the interface at failure would be independent of bond length because it is a "material property".
• It is possible that the "average" joint line stress determined by the failure load divided by the joint line area is not independent of joint line length because the stress distribution is non-uniform. It is possible that most of the load is carried by the first bit of the fibre and longer fibres do not carry much load at positions away from the top of the interface. If so, the average stress would reduce with interface length. This would show that the average stress on fibre interface at failure is not a "material property".

Regards,

Simon