Sparse Structural System Identification and Strain Sensing - New Developments

Abstract:
This seminar addresses the important problems of sparse system identification of
nonlinear structures and associated sensing. Firstly, a sparse system
identification algorithm with l1 - regularization suitable for single degree of
freedom (SDOF) and multiple degree of freedom (MDOF) structural systems with
either nonlinear elastic or inelastic/hysteretic behavior is presented. This new
parametric technique is capable of discovering the underlying governing
equations of the system of interest from input-output data. The technique includes
basis functions that allow the discovery of significant nonlinearities, and hystertic
or inelastic behavior with permanent deformation. Model selection is performed
using Akaike information criterion. Experimental validation of the selected model
is presented. In the second part of the seminar a noncontact laser based optical
strain sensing smart skin (S4)developed from single wall carbon nanotubes is
presented briefly. Measured strain maps obtained using S4 are presented and
compared with maps computed using nonlinear FEM.
Bio:
Satish Nagarajaiah is a Professor of Civil Engineering and of Mechanical
Engineering at Rice University, Houston. His research and teaching focuses on
structural dynamic systems, earthquake engineering, adaptive stiffness structural
systems, structural control, and sparse structural system identification. He has
developed advanced computational techniques for nonlinear dynamic analysis of
base isolated structures that are widely used in practice. He has invented and
developed adaptive stiffness structural systems. His contributions to adaptive
stiffness structural systems have been recognized by NSF CAREER award in
1998 and by ASCE Moissieff award in 2017. He has lead the development of
structural system identification algorithms based on time-frequency methods,
wavelets, sparse regularization, and statistical learning techniques, which has
been recognized by ASCE Raymond C. Reese Research Prize in 2017. Dr.
Nagarajaiah currently serves as the editor of the structural control and health
monitoring international journal [Wiley], and as one of the editors of Mechanical
Systems and Signal Processing Journal [Elsevier]. He served as the managing
editor of ASCE Journal of Structural Engineering from 2011-2018. He is a fellow
of ASCE and a fellow of Structural Engineering Institute