Development of response estimation algorithm with multiresponse data for damaged cable-stayed bridges

Currently, most structural health monitoring (SHM) systems perform localized assessments of structures using measured data to evaluate their overall structural integrity. Consequently, various studies have been conducted to develop global response estimation techniques capable of assessing the overall structural health using limited data. Recently, an algorithm called structural response analysis using a limited amount of multiresponse data (SRALMR) has been developed. This algorithm estimates the global structural response based on the modal expansion method, which expresses structural responses as a superposition of simplified modes. However, SRALMR is limited to estimating responses only in ideally intact structures under steady-state conditions, which poses challenges when applying it to real-world structures with damage during service. To address this limitation, the present study improves the SRALMR method to enable response estimation for actual damaged structures. Through the superposition of response functions from both intact and damaged states, the domain of estimable responses is expanded. This enhanced algorithm is referred to as extended SRALMR (eSRALMR). This study conducted verification using a finite element (FE) model as a step to evaluate the algorithm's performance and to assess its potential applicability in real-world conditions. The results demonstrate that eSRALMR accurately estimates responses in a randomly damaged bridge model, confirming its improved performance over the original SRALMR.