Optimal sensor placement in the lightweight steel framing structures using the novel TTFD approach subjected to near-fault earthquakes

Abstract

Lightweight steel framing (LSF) system has been proposed as an economic system and earthquake resistant. In this study, a LSF structure was modeled using finite element method, which the material properties were defined according to laboratory data. Then, the modal and nonlinear time-history analyses were undertaken using the seismic scaled records of near-fault earthquakes. Moreover, three optimal sensor placement (OSP) methods were utilized, and genetic algorithm was selected to act as the solution of the optimization formulation in the selection of the best sensor placement according to structural dynamic response of LSF system. A novel numerical approach was proposed for OSP, which was called transformed time-history to frequency domain (TTFD) algorithm. The TTFD method uses nonlinear time-history analysis results as an exact seismic response despite the common OSP algorithms utilize the eigenvalue responses. Results show that utilizing an efficient OSP method in structural health monitoring process leads to detecting the critical weak points of sensitive structures, so as to retrofit them.