Brittle failure in Abaqus

[surotm]

Hi there,

Can anyone explain me the results I got from Explicit? I am investigating cracks propagation in hybrid timber-glass beam. It is a I-shaped section and consists of timber flanges and glass web bonded with an adhesive.

Please look at the attached diagram - Force versus vertical deformation. Until an initial crack it is almost perfectly linear. But what happens after the glass failure? What could be the reason that the force changes like a wave?

 

[surotm]

I tried my scalling and dumping coefficients.. Do you have any idea?