A displacement-based formulation of nearly-incompressible fluid element for analysis of large-amplitude liquid sloshing for tuned liquid damper applications | |
| Author | Bui Thanh Tam |
| Call Number | AIT Diss. no. ST-98-01 |
| Subject(s) | Damping (Mechanics) Structural dynamics |
| Note | A dissertation submitted in partial fulfilment of the requirements for the degree of Doctor of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. ST-98-01 |
| Abstract | Recently, there was a growing interest in the implementation of Tuned Liquid Damper (TLD) to suppress undesirable modes of vibration in high.rise structures. The performance of TLD relies mainly on the sloshing of liquid at resonance to absorb and dissipate vibration energy of the structure. For analysis and design an effective TLD, a numerical model of TLD is necessary beside the expensive experiments. It must be able to predict large-amplitude liquid-sloshing responses caused by a near-resonance situation. An impo1iant behavior of the free-surface liquid in a container is its ability to displace without a significant change in volume, known as incompressibility. The numerical model must therefore be able to maintain incompressibility without causing any numerical difficulty in the process. A Lagrangian displacement-based fluid element has been developed to model large amplitude free surface motion of nearly incompressible viscous fluids in a tank of rectangular cross-section under dynamic excitation. The penalty method is employed to enforce the nearly incompressible characteristic of fluids with considering the nonlinear effect of finite distortion of zero-shear low-viscosity fluid elements. For this type of problem, due to the contrast disparity of the stiffness contribution from the extremely high incompressibility and that from the extremely low viscosity of the water in the container, special consideration has to be given to the appropriate selection of the magnitude of the penalty coefficient and the numerical integration of the volumetric strain energy. As a result, the number of Gauss sampling points required for the integration of the volumetric term of tangent stiffness was found by numerical trials and a criterion in selecting penalty coefficient to obtain a reliable solution has been proposed. Effectiveness of the proposed model was verified by experimental data and results from the literature. The results reveal that the proposed nonlinear fluid element can predict nonlinear behaviors of large amplitude sloshing due to dynamic excitation, especially near resonant region, which is the key feature of Tuned Liquid Damper applications. The proposed fluid element can be conveniently incorporated into any existing general purpose finite element program to serve as an effective tool for analysis and design of Tuned Liquid Dampers. |
| Year | 1998 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. ST-98-01 |
| Type | Dissertation |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Worsak Kanok-Nukulchai ; |
| Examination Committee(s) | Pisidhi Karasudhi ;Huynh Ngoc Phien ;Pennung Warnitchai ;Wijeyewickrema, Anil C. ;Hinton, Ernest; |
| Scholarship Donor(s) | Government of Australia ; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1998 |