An approach to seismic response reduction for offshore platforms by the use of the tuned liquid damper is presented in this paper. First of all, the effects of the tuned frequency ratio and excited frequency ratio on ...An approach to seismic response reduction for offshore platforms by the use of the tuned liquid damper is presented in this paper. First of all, the effects of the tuned frequency ratio and excited frequency ratio on the seismic response reduction of the platform structure are investigated. Based on the results, a mechanical model and equation of motion for the TLD-platform system are established. And then effectiveness of the appraoch is verified by numerical calculation.展开更多
In this paper, the control method for fixed offshore platforms using semi-active tuned liquid column damper (TLCD) is presented. The equation of motion for the platform-TLCD control system is given and the semi-active...In this paper, the control method for fixed offshore platforms using semi-active tuned liquid column damper (TLCD) is presented. The equation of motion for the platform-TLCD control system is given and the semi-active control strategy is established. A back propagation artificial neural network (ANN) is used to adjust the orifice opening of TLCD because of the nonlinear motion of liquid in TLCD. The effectiveness of the control method is verified by numerical examples.展开更多
Offshore platforms in seismically active areas should be designed to service severe earthquake excitations with no global structural failure. In seismic design of offshore platforms, it is often necessary to perform a...Offshore platforms in seismically active areas should be designed to service severe earthquake excitations with no global structural failure. In seismic design of offshore platforms, it is often necessary to perform a dynamic analysis that accounts for nonlinear pile soil structures interaction effects. This paper summarizes the nonlinear dynamic analysis of a 3-D model of a typical Jacket-Type platform which is installed in Persian Gulf (SPD1), under simultaneously wave and earthquake loading has been conducted. It is assumed that they act in the same and different directions. The interaction between soil and piles is modeled by equivalent pile length theory. The structure is modeled by finite element method (Ansys Inc.). It be concluded that when the longitudinal components of the earthquake and wave are in different directions, an increase on the response of platform can be seen.展开更多
文摘An approach to seismic response reduction for offshore platforms by the use of the tuned liquid damper is presented in this paper. First of all, the effects of the tuned frequency ratio and excited frequency ratio on the seismic response reduction of the platform structure are investigated. Based on the results, a mechanical model and equation of motion for the TLD-platform system are established. And then effectiveness of the appraoch is verified by numerical calculation.
文摘In this paper, the control method for fixed offshore platforms using semi-active tuned liquid column damper (TLCD) is presented. The equation of motion for the platform-TLCD control system is given and the semi-active control strategy is established. A back propagation artificial neural network (ANN) is used to adjust the orifice opening of TLCD because of the nonlinear motion of liquid in TLCD. The effectiveness of the control method is verified by numerical examples.
文摘Offshore platforms in seismically active areas should be designed to service severe earthquake excitations with no global structural failure. In seismic design of offshore platforms, it is often necessary to perform a dynamic analysis that accounts for nonlinear pile soil structures interaction effects. This paper summarizes the nonlinear dynamic analysis of a 3-D model of a typical Jacket-Type platform which is installed in Persian Gulf (SPD1), under simultaneously wave and earthquake loading has been conducted. It is assumed that they act in the same and different directions. The interaction between soil and piles is modeled by equivalent pile length theory. The structure is modeled by finite element method (Ansys Inc.). It be concluded that when the longitudinal components of the earthquake and wave are in different directions, an increase on the response of platform can be seen.
