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

Abstract

High-tech equipments engaged in the production of ultra-precision products have very stringent vibration criteria for their functionality in normal operation conditions and their safety during an earthquake. Most previous investigations were based on simplified planar models of building structures, despite the fact that real ground motions and structures are always three-dimensional. This paper hence presents a threedimensional analytical study of a hybrid platform on which high-tech equipments are mounted for their vibration mitigation. The design methodology of the hybrid platform proposed in this study is based on dual-level performance objectives for high-tech equipments: safety against seismic hazard and functionality against traffic-induced microvibration. The passive devices (represented by springs and viscous dampers) and the active actuators are designed, respectively, to meet vibration criteria corresponding to safety level and functionality level. A prototype three-story building with high-tech equipments installed on the second floor is selected in the case study to evaluate the effectiveness of the hybrid platform. The optimal location of the platform on the second building floor is determined during the design procedure in terms of the minimal H 2 cost function of absolute velocity response. The simulation of the coupled actuator-platformbuilding system subjected to three-dimensional ground motions indicates that the optimally designed hybrid platform can well achieve the dual target performance and effectively mitigate vibration at both ground motion levels.

Active Microvibration Control of Tool Platforms Installed on the Floors Subjected to Moving Vehicles in Industrial Factories

“…Te hybrid control platform consisted of active hydraulic actuators and passive mounts with springs and dashpots between the platform and building. Numerical results demonstrated that the vibration of the passive control platform may exceed VC-B, whereas that of the hybrid-controlled platform could be efectively suppressed to meet VC-E. Hong et al [9] constructed a three-dimensional fnite element building model with a hybrid platform subjected to three-dimensional ground excitations. Te hybrid platform mounted on the second foor of the building consisted of several pairs of passive devices and active actuators.…”

Experimental study on seismic vibration control of stockers in wafer and LCD panel fabs

“…al. [11] presented a three-dimensional analytical study of a hybrid platform on which high-tech equipments are mounted for their vibration mitigation. The literatures mentioned above have proven that small, customized viscous dampers are effective means of reducing the unwanted vibration of objects or building content.…”

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.…”