Validation of joint input-state estimation for force identification and response estimation in structural dynamics

Abstract

This paper presents a validation of a recently developed joint input-state estimation algorithm for force identification and response estimation in structural dynamics, using data obtained from in situ experiments on a footbridge. First, the algorithm is used to identify two impact forces applied to the bridge deck. Next, the algorithm is used to extrapolate measured accelerations due to wind loading to unmeasured locations in the structure. The dynamic model of the footbridge used in the system inversion is obtained from a detailed finite element model, that is calibrated using a set of experimental modal characteristics. The quality of the estimated forces and accelerations is assessed by comparison with the corresponding measured quantities. In both cases, a very good overall agreement is obtained.