FEM deals with continuum problems while DEM deals with discontinuum problems. The conflict here is that in compaction, we should be dealing with the rearrangement of discrete elements of soil matrix though in their fine form talking about lateritic soils. But in Discrete Element algorithm, the boundary under study has to be descritized into Finite Elements and finite element algorithms employed in the modeling operation. How does one deal with this quasi-empirical situation?
Thank you Behzad, this is really helpful. We could actually collaborate in some of the modeling operations we do with DEM. Your ideas would be invaluable and appreciated. [email protected].
Although DEM is a powerful tool, but it still has limitations of considering millions of particles due to the lack of computational power. Truly speaking, DEM is best for capturing the micro- processes that evolve during any mechanical loading of a small scale system. You can monitor the physical processes and explain the phenomena by DEM that is otherwise impossible to observe and discuss using experiment. However, to model the real scale-problem, FEM is still preferable.
Hi,
I agree with Mahmud. Moreover, I would like to emphasize that the common viewpoint in soil mechanics is a macroscopic one. This has led to matured phenomenological constitutive equations to compute soil stresses and deformation based on the principles of continuum mechanics. These can be implemented into FEM codes if not already available.
Also note that inter-particle friction and cohesion (which is in fact adhesion in that case) on the microscale generally is not equal to the internal friction angle and cohesion that can be measured in soil mechanical laboratory tests on the macroscale. The macroscopic quantities also depends on the internal structure, particle shape, individual particle motion, etc., which is difficult to measure and to model with DEM.
Regards
@Mahmud and Daniel, your submissions are very helpful. I appreciate. Many thanks
@Daniel, I would appreciate if you could send me copies of your works on this subject. Or even books that could help. Thanks again
Concerning FEM in geotechnical engineering, see
- D. M. Potts, L. Zdravkovic: Finite Element Analysis in Geotechnical Engineering – Theory, Thomas Telford, London, 1999
- D. M. Potts, L. Zdravkovic: Finite Element Analysis in Geotechnical Engineering
– Application, Thomas Telford, London, 2001
- O. C. Zienkiewicz, A. H. C. Chan u.a.: Computational Geomechanics with Special Reference to Earthquake Engineering, John Wiley & Sons, Chichester, 1999
If you want to study my work, see my publications on RG or on my homepage at http://www.goo.gl/PlqPqn
Regards