MODELLING A CIRCULAR/ELLIPTICAL FRONT AXIAL CRACK IN A PIPE WALL

[mechsid]

I am able to model circular/elliptical fronted cracks in a plate but i am stuck with modelling the crack tip region with swept wedge elements and structured hex elements in a wall of a pipe(cylinder).

Using partition tool in ABAQUS i find that while sweep/extruding the J-contour edges sketched on a flat face they do not extend fully to the inner/outer wall of the pipe especially when modelling axial semi-thickness cracks.

Is there a special program to generate this elemental/nodal-data or can i do it in ABAQUS-CAE using partioning tools as for flat plates.

I am using the QUEST-RELIABILITY CORPS benchmark for crack tip meshing.

 

[bfillery]

Hi mechsid

The best way I have found to do this is to 1st create a mesh part of the cracked plate and then write a python script to transform the node locations in the plate to those of the required cylindrical geometry.

bfillery

 

[mechsid]

Dear Bfillery,

Are there any special purpose programs available for causing these node transformations for variety of crack topologies.

Thanks
mechsid

 

[bfillery]

Hi mechsid

There are no special purpose programs for this transformation that i know of. You will have to write your own python code to do this. There are a few commercial programs that do generalised crack tip meshing such as Zencrack.

bfillery

 

[CharlesRobert]

Hi,

If you can get some tech doc of SAMCEF, it is very strong for fracture problem!

Br,Charle