Community Research and Development Information Service - CORDIS


Pseudo Dynamic tests (PSD-tests) are performed on full scale models of concrete and steel buildings subjected to earthquakes. The PSD test method combines on-line computer simulation with experimental data to provide realistic dynamic response histories even for severely damaged structures which exhibition-linear behaviour. This paper presents, compares and evaluates 3 different algorithms for on-line estimation of secant stiffness matrices during PSD tests. The first algorithm uses the least square (LS) solution to a set of linear equations; the second algorithm is based on the recursive least square (RLS) techniques; finally the recursive time domain identification procedure Extended Kalman Filtering (EKF) technique is used in a third algorithm. The LS algorithm and the RLS algorithm use the displacement and the restoring forces as input, while the displacement and the base acceleration are used as inputs in the EKF algorithm. Results show that the LS-algorithm fails totally due to a lack of robustness. The RLS-algorithm and the EKF-algorithm give quite good estimates at the start and the end of the test, where the secant stiffness matrix is known, the RLS-algorithm being the most robustness of the two algorithms. However it cannot be used during real earthquakes where the restoring force: are not measurable. In the latter case the EKF-algorithm should be used.

Additional information

Authors: RYTTER A, JRC Ispra (IT);NEGRO P, JRC Ispra (IT);KIRKEGAARD P H, Aalborg University, Department of Building Technology and Structural Engineering (DK)
Bibliographic Reference: Paper presented: Eurodyn 96, Florence (IT), June 5-8, 1996
Availability: Available from (1) as Paper EN 39768 ORA
Record Number: 199610679 / Last updated on: 1996-06-21
Original language: en
Available languages: en