Hybrid platform for vibration control of high‐tech equipment in buildings subject to ground motion. Part 2: analysis

Abstract

SUMMARYThe experimental results of using a hybrid platform to mitigate vibration of a batch of high-tech equipment installed in a building subject to nearby tra c-induced ground motion have been presented and discussed in the companion paper. Based on the identiÿed dynamic properties of both the building and the platform, this paper ÿrst establishes an analytical model for hybrid control of the building-platform system subject to ground motion in terms of the absolute co-ordinate to facilitate the absolute velocity feedback control strategy used in the experiment. The tra c-induced ground motion used in the experiment is then employed as input to the analytical model to compute the dynamic response of the building-platform system. The computed results are compared with the measured results, and the comparison is found to be satisfactory. Based on the veriÿed analytical model, coupling e ects between the building and platform are then investigated. A parametric study is ÿnally conducted to further assess the performance of both passive and hybrid platforms at microvibration level. The analytical study shows that the dynamic interaction between the building and platform should be taken into consideration. The hybrid control is e ective in reducing both velocity response and drift of the platform/hightech equipment at microvibration level with reasonable control force.

A study on AGV-induced floor micro-vibration in TFT-LCD high-technology fabs

“…Over the last two decades, micro‐vibration has been intensively studied in concerns of human comfort and production yield for office buildings, biotechnology or metrology labs, and semiconductor fabs 4–16. Vibration control for sensitive equipment by using isolation devices or active control systems 14–25 has also been widely explored.…”

“…Over the last two decades, micro-vibration has been intensively studied in concerns of human comfort and production yield for office buildings, biotechnology or metrology labs, and semiconductor fabs [4][5][6][7][8][9][10][11][12][13][14][15][16]. Vibration control for sensitive equipment by using isolation devices or active control systems [14][15][16][17][18][19][20][21][22][23][24][25] has also been widely explored. Figure 2 illustrates a typical double-fab TFT-LCD building that was piled up with two clean rooms and the supporting sub-fabs.…”

Three‐dimensional vibration control of high‐tech facilities against earthquakes and microvibration using hybrid platform

“…Yang and Agrawal [3] compared the effectiveness of various protective systems for high-tech facilities against microvibration and earthquakes, and concluded that hybrid floor isolation systems, consisting of passive floor isolators and stand-by passive viscous dampers to be activated only during seismic events, are most effective and practical. Through a series of analytical studies and shaking table tests of a coupled platform-shear building model, Xu et al [4,5] and Yang et al [6] verified the effectiveness of a hybrid platform designed for the mitigation of traffic-induced microvibration for high-tech equipments. In addition, Xu and Li [7], Xu and Guo [8] explored the feasibility of using a hybrid platform to mitigate vibrations induced by both earthquakes and road traffic.…”

Performance of structure–equipment systems with a novel roll-n-cage isolation bearing

“…As for protection of high-tech equipment from microor ambient vibrations, Yang and Agrawal [20] showed that passive hybrid floor isolation systems are more effective in mitigating the equipment response than passive or hybrid base isolation systems. Xu et al [21] and Yang et al [22] studied the response of a batch of 0045 high-tech equipment mounted on a hybrid platform, which in turn is mounted on a building floor. Both their theoretical and experimental studies showed that the hybrid platform is more effective in mitigating the velocity response of the high-tech equipment than the passive platform.…”