IDENTIFICATION OF A SYSTEM NEEDED FOR 100 T SHAKE TABLE

Abstract

The objective of this dissertation is to identify a system needed for a 100t (mass) shake table which can be subjected to three—dimensional earthquake. motion. For this, the shake table of 25t (mass) and the size 6.Om x 6.Om in plan and having height 3.0 m, is considered. The shake table is supposed to behave as the rigid body and is possibly made out of aluminium alloy. The actual analysis and design of the shake table are not considered. The shake table is driven by two horizontal actuators in the X direction, two actuTtors in the Y direction and four actu,-tors in the Z direction. These actuators are driven by electrohydraulic servomechanism. The maximum values of accele-rations and eccentricities between centre of gravity of the model/ prototype and the shake table in the X,Y and Z directions are assumed. Based on these, static and dynamic forces and moments required to be resisted by the actuators are obtained for deter-mining the capacity of the actuator. without preload. The preload connections are provided to the actuators to prevent the overturning of the table sbout both the horizontal axes and the rotation about the vertical axis by oil columns spring effect. The preload connections reduce the capacity of the vertical actuators substantially and increase the capacity of the horizontal actuators marginally,. The total power required to drive the actuators is found by considering thirty three percent pressure drop across the power pack and the piston of actuators so as to achieve optimum efficiency.