Multiple layers with frictional sliding in between them
Multiple layers with frictional sliding in between them
(OP)
Hi,
I have been trying to develop a 2 layered large scale model for geological applications. Due to the nature of the problem, I have to define contacts (10) between all surfaces that can come in contact with one another during the analysis.
When I run the model, it runs just fine for upto t = 0.08 (of a total of 1 unit) and the time increments begin becoming vanishingly small from this point forward. I tried my best to remove any over-constraints, but I cannot understand what is causing the problem.
I am attaching the cae file. Can somebody please suggest to me what may be wrong and if there is a more elegant way to define the contacts.
Thanks in advance
SS
I have been trying to develop a 2 layered large scale model for geological applications. Due to the nature of the problem, I have to define contacts (10) between all surfaces that can come in contact with one another during the analysis.
When I run the model, it runs just fine for upto t = 0.08 (of a total of 1 unit) and the time increments begin becoming vanishingly small from this point forward. I tried my best to remove any over-constraints, but I cannot understand what is causing the problem.
I am attaching the cae file. Can somebody please suggest to me what may be wrong and if there is a more elegant way to define the contacts.
Thanks in advance
SS





RE: Multiple layers with frictional sliding in between them
Rob Stupplebeen
RE: Multiple layers with frictional sliding in between them
In my case, I managed to avoid the situation by allowing seperation and holding the contacts together with 'tie' constraints. Hope that helps.
And completely unrelated: I looked at your cae file, and I'm wondering where you got the nice tabular data for the plastic behaviour of the granite and sandstone. Your own measurements? Some citable source?
RE: Multiple layers with frictional sliding in between them
I will try both your suggestions and see what happens. I will update the status on this thread.
Rmettier,
The elasto-plastic hardening values for Granite and Sandstone are from published articles. These are for testing my models only;
Here are the references
Sandstone : *Zhu, W., Montési, L. and Wong, T.-f. (1997) Shear-enhanced compaction and permeability reduction: triaxial extension tests on porous sandstone, Mechanics of Materials, 25, 199-214.
( I have included volumetric strains from this paper in my model - if you have any suggestions as to how I can do it, please let me know)
Granite: Tullis and Yund, 1977. J. Tullis and R.A. Yund, Experimental deformation of dry Westerly granite. Journal of Geophysical Research 82 (1977), pp. 5705–5718