In the paper, the authors investigate to find the optimal parameters of the TMD-D and DVA absorbers in order to optimally reduce the vibration for the inverse pendulum system. These research results are applied to reduce the vibration for the articulated tower in the ocean. | Vietnam Journal of Mechanics, VAST, Vol. 32, No. 1 (2010), pp. 59 – 69 OPTIMAL PARAMETERS OF VIBRATION REDUCTION SYSTEM TMD-D AND DVA FOR AN INVERTED PENDULUM TYPE STRUCTURE Khong Doan Dien, Nguyen Duy Chinh Vietnam Water Resources University, 175 Tay Son, Hanoi, Vietnam Abstract. N. D. Anh, K. D. Dien and N. D. Chinh in [1] have studied the vibration of inverse pendulum system installed with the vibration reduction system TMD-D and DVA. These results implemented by numerical simulation for the articulated tower in the ocean show that the obtained oscillations in some cases with installed absorber increase the amplitude of vibration when compared to the case without absorber. It is a fact that when simulation is employed, the parameters of TMD-D and DVA are chosen arbitrarily without optimal design. In the paper, the authors investigate to find the optimal parameters of the TMD-D and DVA absorbers in order to optimally reduce the vibration for the inverse pendulum system. These research results are applied to reduce the vibration for the articulated tower in the ocean. 1. INTRODUCTION In the paper [2] K. D. Dien and N. D. Chinh have studied the vibration of inverse pendulum system installed with the TMD-D (TMD acts to reduce the vertical vibration) and TMD-N (TMD acts in order to reduce the horizontal vibration). N. D. Chinh has investigated the inverse pendulum system installed only with TMD-N [3]. These researches are shown that if the TMD-N is installed in the inverse pendulum system, the horizontal vibration will be reduced without reducing the amplitude of vertical vibration. Therefore, if the inverse pendulum system has a horizontally acted force, the structure will have a horizontal oscillation. In this case, the TMD-N should be installed in the system. On the opposite view, if the TMD-D is installed, this absorber only has the effectiveness of reducing the oscillation in vertical direction of inverse pendulum system without reducing the amplitude of .
