Passive control systems

Applicability of passive control systems for the seismic protection of oil refinery components... 

Table 2. Seismic damages of industrial process components and passive control systems.

Paolacci F., Giannini R., De Angelis M, Ciucci M, (2010). Applicability of passive control systems for the seismic protection of major-hazard industrial plants. Sustainable Development Strategies for Constructions in Europe and China, 19-20, Rome, Italy... 

Moghaddam S, Pengwang E, Lin K, Masel R, Shannon M (2008) Millimeter-scale fuel cell with on board fuel and passive control system. J Microelectromech Syst 17 1388-1395... 

Kasai, K., Fu, Y. Watanabe, A. 1998. Passive control systems for seismic damage mitigation. Journal of Structural Engineering 124 (5) 501-512. 

A fail-safe passive control system is assumed to govern the reactor system. In this system, numerous signals from various redundant detectors of different origin enter the circuit. When all signals are within the pre-defmed ranges of values, then the pump power will be in the on position. In any other situation, the coolant pump is in its normal switched off position, and the fuel elements leave the reactor core, driven by gravity, and become deposited in a passively cooled fuel chamber. 

The dynamic response of civil engineering structures subjected to earthquake excitation can be reduced by using passive control systems such as energy dissipation devices (e.g. viscous dampers, etc.). The advantage of these systems with respect to active and semi-active control systems consist in the fact that they don t require any power supply, therefore are quite reliable and they require least maintenance. 

Passive Control System A system of strac-tural control whose characteristic is determined once by an appropriate design method before the device is in place. 

The tuned mass damper (TMD) system is a typical form of control devices including a mass, spring, and a viscous fluid damper, which can be attached to the main structure at one of its degrees offreedom. This system is one ofthe well-accepted devices to control flexible structures, particularly, tall buildings. In this passive control system, if its damping ratio or stiffness of the spring changes with time, then it is called a semi-active tuned mass damper (STMD). 

Lever arms (Figure Ic) are proposed to increase the efficiency of damping devices by magnifying the inter-story drifts and drift velocities, transferred from the structure to dampers (Gluck, 1996). This idea was further developed for design of structures with optimal viscous dampers (Ribakov, 2000). The equivalent lever arm approach is used to change the effect of off the shelf linear viscous devices yielding an optimal passive control system. 

Acomparison among the four categories previously described shows thatthe passive control systems are more feasible and reliable since devices are simpler and do not depend on any source of... 

Passive control systems, as previously stated, could be defined as inert mechanisms added to the structure to improve its behaviour in response to the d5mamic forces associated with wind and especially earthquakes. The behaviour of these systems is based on deforming inelastically in response to the excitation. 

Summary This book addresses the design optimization of active and passive control systems including earthquake engineering and tuned mass damper research topics and their hnk — Provided by pubhsher. 

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