Development of a hybrid SHM of cable bridges based on the mixed probability density function

Abstract

The previous studies on structural health monitoring (SHM) of cable bridges have assessed the health of bridges by a deterministic way or by assuming a calculated health index as a normal distribution. However, various case studies have shown that the health index obtained from field measurement data does not generate a Gaussian distribution due to various factors. In this study, a new mixed probability density function (PDF) is proposed for each local health index based on the findings. The joint PDF for each type of data is determined from the obtained local PDFs. The hybrid index of a bridge is then determined by a combination of local indices. The impact of local damage to the overall health of a bridge is evaluated by taking into account the weight of the sensor type and the weight of the sensor location related to the importance of the member. The proposed hybrid SHM has been verified through a simulation study on a truss structure and by applying it to an existing cable-stayed bridge.