Towards the development of boundary elements for axisymmetric porous layers | |
| Author | Rimal, Mahesh Raj |
| Call Number | AIT Thesis no. ST-89-15 |
| Subject(s) | Porous materials--Mathematical models Boundary element methods |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | An axisymmetric boundary super element to model the fa r field behaviour of a layered porous halfspace is formulated based on the Cleary - Cheng reciprocal relationship. Axisymmetric fundamental solutions are adopted for the development of the Boundary Integral Equation Method. As the fundamental solutions are not in closed form and involve infinite integrals, an accurate evaluation of these functions is to be conduct ed. Based on some numerical examples of different finite elements a suitable finite element mesh is prepared to mode l the full space . The analytical ring force and source solutions are verified in this study. Although the results obtained by the finite element analysis were seen to agree well with the analytical ones, difficulties with respect to computational effort and integration of infinite integrals indicate that further research is still needed. Time dependency of the problem was removed by Laplace transformation and the inversion was carried out by the approximate method proposed by Schapery. For the inverse Hankel transforms, numerical integration was performed by trapezoidal rule. The idea of zoning technique could lead to several boundary super elements for modelling layered domains by satisfying interface compatibilities. The boundary element scheme for such unbounded problems has an obvious advantage over other domain type methods as t he fundamental solutions obey the radiating conditions at the far field. For the near field, finite elements could be adopted. A B3-2 element having 3 nodes for displacement and 2 nodes for excess pore pressure was also developed in this study for coupling with the Q84 finite element at the interface. |
| Year | 1989 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Worsak Kanok-Nukulchai |
| Examination Committee(s) | Karasudhi, Pisidhi ;Wireland, Martin |
| Scholarship Donor(s) | The Government of Australia |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |