ABAQUS - VCCT: DCB Mode I Fracture Toughness

[Shawn Utah]

I am attempting to create a VCCT simulation to measure the fracture toughness (G_IC) of a DCB specimen. I am actually not trying to propagate the crack as I am trying to better understand pre-propagation values.

My larger issue is the bottom arm (designated as slave) is not responding to the applied force whereas the top arm is behaving as expected. The top and bottom arms are symmetric so I would assume the same displacement. An edge load is applied in the vertical 2 direction on the top arm. The bottom arm is fixed in U1, U2, and U3 but ONLY on the outer edge of the crack. The same material is applied to both arms.

Does anyone have any suspicions as to why the bottom arm appears to be completely fixed and not mirroring the top arm?

I followed this

https://abaqus-docs.mit.edu/2017/English/SIMACAECAERefMap/simacae-t-enghelpvcctstd.htm

while making my VCCT parameters.

 

[FEA way]

If the outer edge of the bottom layer is fixed then you won’t be able to achieve the desired effect. Try fixing only the edge on the right and pulling both left edges in opposite directions. That’s how it’s usually done for this type of specimen.