Quasi-static axial load transfer to a saturated porous elastic half-space from an embedded elastic rod | |
| Author | Boonsrang Niumpradit |
| Call Number | AIT Diss. no.D38 |
| Subject(s) | Elastic rods and wires Strains and stresses |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering. |
| Publisher | Asian Institute of Technology |
| Abstract | The quasi-static development of the force, pore pressure and displacements is analysed in the form of aa circular elastic rod partially embedded in a saturated porous elastic half-space and loaded axially on the top. The porous elastic half-space is governed by Biot's theory. The problem is decomposed into two systems, namely, an extended porous elastic half-space in the absence of the rod characterized by the material constants of the meduim; and a ficti-tious rod represented by a Young's modulus equal to the difference of the Young's moduli of the real rod and the medium. The unknown fictitious rod force is determined under the approximation that the axial strain in the ficti-tious rod is equal to the average vertical normal strain in the extended porous elastic half-space over a rod cross section at the original rod location. The problem is found to be governed by a Fredholm intergral equation of the second kind. Laplace transform is applied to time functuins involved, and Hankel transform to the functons of radial coordinate of which the origin is at the center of the rod. By setting the Laplace transform parameter equal to zero and infinity, respectively, the governing integral equation for final and initial solutions are obtained and solved by an appropriate numerical methid. Adopting Schapery's technique to obtain the approximate inverse Laplace transform, the Fredholm integral equation for the transient solution is solved by a "modified" Ritz's method with the solution being assumed in the same form as that of the final solution. Numerical solutions are obtained for various practical values of the parameters involved. Results are perdented in graphs for the purposes of analysis and design of such structures. Time is found to have greater effect on the real rod force of a softer rod. The pore pressure has a maximum value near the top end of the rod, and decays toward the tip for a soft rod, but rises again to another maximum at the tip for a rigid rod. while a rod shortening changes little with time, is tip displacement does change significantly. The final real rod force increases with increasing rod stiffness. |
| Year | 1978 |
| Type | Dissertation |
| School | AIT Publication (Year <=1978) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Dissertation (D) (Year <=1978) |
| Chairperson(s) | Pisidhi Karasudhi; |
| Examination Committee(s) | Anat Arbhabhirama;Balasubramaniam, A.S.;Chiev,Khus;Tanabe, Tadaaki ;Achenbach, Jan D. ; |
| Scholarship Donor(s) | Royal Thai Army; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1978 |