การจำลองเพื่อหาค่าคุณลักษณะทางพลศาสตร์ของตัวหน่วงปรับค่าได้ชนิดของเหลวแบบมีแกนด้วยวิธีการประมาณเส้นทางการไหลเป็นรูปวงรี

Abstract

Tuned Liquid Column Damper (TLCDs) and Liquid Column Vibration Absorber (LCVAs) are mechanical dampers for structural vibration control under earthquake excitation. In previous research, simplified effective length method is applied to predict the frequency response of LCVA. This existing method is accurate for LCVA with small transition zone, but it had some discrepancies when the transition zone of LCVA got larger. This research proposes the elliptical flow path estimation method to predict the frequency response of LCVA with large transition zone. According to the comparison between shake table experiment and simulation results, the elliptical flow path estimation method can effectively predict the frequency response for both liquid displacement and interaction force of LCVA with large transition zone, as good as for small transition zone. The researcher recommends that the ratio of corner-to-corner width to the horizontal length of 0.3 should be the initial value of large transition zone. The effectiveness of LCVA for reducing vibration and damage of 5 degrees of freedom structure was investigated under 6 harmonic-liked long-distance earthquakes. The behavior of structure was assumed as elastic-perfectly plastic. F.Sadek's suggestion for design parameters of LCVA was used to design optimal configuration of LCVA for the structure. For specified earthquakes, LCVA effectively reduces the response and damage of the structure under medium intensity earthquakes that resonate with structure. On the other hand, LCVA is not effective under strong resonance excitations that their peak ground accelerations exceed 98 gal.