Simple piecewise linearisation in time series for time-domain inversion to estimate physical parameters of nonlinear structures

Ryuta Enokida, Koichi Kajiwara

    Research output: Contribution to journalArticlepeer-review

    Abstract

    This study introduces simple piecewise linearisation in time series (SPLiTS), for time-domain inversion (TDI) to estimate the physical parameters of nonlinear structures. SPLiTS considers a nonlinear structure to be a set of piecewise linearised structures based on each half-cycle wave in the displacement response data. For the linearisation, SPLiTS intentionally minimises the effect of the central point shift that damaged structures commonly display. After theoretically introducing SPLiTS to the response data of single-/multi-degree-of-freedom (SDOF/MDOF) structures, parameter estimations are performed for data obtained from numerical simulations and experiments. The efficiency of consideration of the central-point shift is demonstrated in parameter estimations for numerical simulations where response data are obtained by a nonlinear SDOF structure having a trilinear hysteretic spring. SPLiTS is then applied to experimental data from shaking table tests, in which a specimen, imitating a one-storey structure, displayed yielding behaviour. TDI with SPLiTS reasonably estimates physical parameters that show increased damping and decreased stiffness in time series at the inelastic range. Next, SPLiTS is applied to experimental data from shaking table tests conducted for a full-scale, three-storey structure at E-Defense in 2013. The damping coefficient and stiffness of each storey are reasonably estimated for the specimen under different amplitudes. For these experimental data, estimated structural energy absorption calculated by damping in the time series corresponds well with the structural damage of the specimens. Thus, structural energy absorption is proven to be a useful index for indicating structural damage.

    Original languageEnglish
    Article numbere2606
    JournalStructural Control and Health Monitoring
    Volume27
    Issue number10
    DOIs
    Publication statusPublished - 2020 Oct 1

    Keywords

    • physical parameter estimation
    • shake table test
    • structural energy absorption
    • structural health monitoring
    • system identification
    • time-domain inversion

    ASJC Scopus subject areas

    • Civil and Structural Engineering
    • Building and Construction
    • Mechanics of Materials

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