|
Estimation Reaction Force and Position of Center of Gravity for Elastic Supported Rigid Body Using Measured Acceleration Jungrae KIM
ABSTRACT This paper presents two types of scheme to estimate reaction force of elastic support and center of gravity (COG)'s position and displacement for elastic supported structure. Direct measurement of reaction force of elastic support demands expensive cost and lots of effort. In addition, calculated COG's position at the design stage does not reflect the errors induced during construction or production process and change of structure system in service. In order to overcome this problem, this study proposes alternative methods estimating reaction force and COG's position by applying rigid body kinematics and displacement reconstruction scheme to acceleration measured at surface of structure. In order to calculate reaction force, the relative acceleration of elastic support should be calculated by using rigid body kinematics, and the deformation is obtained by applying displacement reconstruction scheme to calculated acceleration. Finally, the reaction force is calculated by using the force-deformation relation of the elastic support. The position of the center of gravity is estimated by optimization problem which minimizes the functional residual of acceleration of COG calculated by Newton's second law of motion and rigid body kinetics. Finally, the acceleration of the center of gravity is obtained by the rigid body kinetics, and the displacement is calculated by applying the displacement reconstruction scheme. To verify the proposed technique, numerical examples are constructed and applied to the structure connected fixed body and moving body. Key Word Rigid body kinetics, Displacement reconstruction scheme, Reaction force of elastic support, Position of center of graivty.
|