Structural damage detection using optimal sensor placement technique from measured acceleration during earthquake

초록

This paper presents a system identification (SI) scheme in time domain using measured acceleration data. The error function is defined as the time integral of the least square errors between the measured acceleration and the calculated acceleration by a mathematical model. Damping parameters as well as stiffness properties of a structure are considered as system parameters. The structural damping is modeled by the Rayleigh damping. A regularization function defined by the L1-norm of the first derivative of system parameters with respect to time is proposed to alleviate the ill-posed characteristics of inverse problems and to accommodate discontinuities of system parameters in time. The time window concept is proposed to trace variation of system parameters in time. Fisher Information Matrix is formulated in terms of acceleration sensitivity with respect to structural system parameters. A scheme of an effective independence distribution vector has been applied to determine optimal locations of accelerometers. Numerical simulation study is performed through a two-span continuous truss.