Identification of dynamic forces using group-sparsity in frequency domainIdentification of dynamic forces using group-sparsity in frequency domain
Faculty of Applied Engineering Sciences
Optical Metrology, 3D design and Mechanics (Op3Mech)
Mechanical systems and signal processing. - London
70-71(2016), p. 756-768
University of Antwerp
The knowledge of acting dynamic forces is required for the design of structures. Given the structural model, inverse techniques offer the possibility to reconstruct the system's input forces from vibration data. The inverse problem is highly sensitive to measurement noise, and the classical pseudo-inverse method generally fails to find the correct loads. In this paper we propose a new penalty function that combines the advantages of the l(p)-norm properties, together with a modified iterative optimization technique. The new algorithm (G-FISTA) is used to localize and reconstruct dynamic point-forces on a beam structure, with no prior knowledge on the force locations. The algorithm is validated by means of several simulations and experiments. The strain data is measured using Fiber Bragg Gratings (FBG) attached to the beam. The obtained results show that the location and time history of point forces are better estimated using the proposed technique. (C) 2015 Elsevier Ltd. All rights reserved.