Ensemble Kalman Filter Finite Element Method Applied to Dynamic Motion of Elastic Body

The purpose of this research is to obtain an estimation of behavior of an elastic body based on errorneous observations. To do this, the ensemble Kalman filter finite element method is used. In numerical study, a three dimensional elastic body is considered. The Iwatayama tunnel is employed. This construction site is located in Gifu prefecture, in Japan. The external force is applied to the tunnel face. As the boundary condition, bottom of the computational model is fixed in all directions. Dynamic motion is caused by the external force applied to the body. Observation data of acceleration at observation points are necessity to estimate acceleration at some other points. In this study, artificial data is used. Computed values plus the white Gaussian noise is used as artificial observations. The finite element method is applied to the spatial discretization and the linear acceleration method(Newmark β method) is used as the temporal interpolation. Finally, the estimation is compared with the results by the finite element method, and effectiveness of the EnKF is verified.We suggest that an ensemble of size 40 and 100 to consider the relation between the size of ensemble members and accuracy of the EnKF.