Cohesive surface - traction separation peak value

[StevenJS]

Hi all,

I'm working on a study with cohesive elements and cohesive surfaces in it.
However when studying the cohesive elements in Abaqus i found that the behavior is not as i expected.

I'm using a traction seperation diagram to model the behavior (input=energy, thus area under the traction-separation curve).
When i plot the traction separation curve of the cohesive surface between 2 single elements (2 parts, both existing of 1 element), i get the following curve:
In this figure for two different cohesive materials the behavior is plotted (however the same behavior occurs).

At the maximum of the traction-separation curve there is a large peak. Why does this peek in traction occurs.
The maximum traction for the Fibre-epoxy interface should be 0,000025 and for the Epoxy-interface element 0,00005.

Thanks in advance!
Steven