Ambient vibration re-testing and operational modal analysis of the Humber Bridge

Abstract

An ambient vibration survey of the Humber Bridge was carried out in July 2008 by a combined team from the UK, Portugal and Hong Kong. The exercise had several purposes that included the evaluation of current technology for instrumentation and system identification and the generation of an experimental data set of modal properties to be used for validation and updating of finite element models for scenario simulation and structural health monitoring. The exercise was conducted as part of a project aimed at developing online diagnosis capabilities for three landmark European suspension bridges.Ten stand-alone triaxial acceleration recorders were deployed at locations along all three spans and in all four pylons during five days of consecutive one-hour recordings. Time series segments from the recorders were merged, and several operational modal analysis techniques were used to analyse these data and assemble modal models representing the global behavior of the bridge in all three dimensions for all components of the structure.The paper describes the equipment and procedures used for the exercise, compares the operational modal analysis (OMA) technology used for system identification and presents modal parameters for key vibration modes of the complete structure. suspension bridge operational modal analysis structural identification 4

Explaining operational modal analysis with data from an arch bridge

“…Now, it is relevant to point out some works with recent and interesting applications. In [47], it is described the ambient vibration test of the Humber Bridge, the largest suspension bridge in the United Kingdom; Siringoringo and Fujino [48] describe the processing of a database collected in a suspension bridge in Japan (Hakucho Bridge); in [49] several relevant applications on bridges and other special structures are presented; in [50], it is demonstrated the usefulness of ambient vibration tests in the context of the implementation of vibration control devices; Pakzad and Fences [51] present the results obtained with an ambient vibration test performed on the Golden Gate Bridge with wireless sensors; Carne and James III [52] describe the use of OMA in wind turbines testing; reference [53] characterizes the monitoring of historical masonry structures, taking profit from OMA.…”

“…(46) was constructed using the previously presented expressions and adopting for p (the polynomial order) values between 2 and 10. A a matrix was determined for each of the 9 considered model orders using the equations presented in (47) and also imposing A p instead of A 0 to be an identity matrix. The obtained RMFD models were converted to state-space models from which mode estimates were extracted.…”

Stability of dynamic response of suspension bridges

“…It is worth noting that the symmetric modes include trigonometric and hyperbolic functions, conversely the skew-symmetric ones are represented by simple sinusoidal shapes. The influence of the main parameters 1 2 , 2 , 2 , and 2 has been investigated through a parametric analysis, based on the available data collected from the literature [5,12,[35][36][37][38][39][40][41][42][43][44]. Besides realistic values, also extreme conditions are considered such as 1 2 = 0 (flat cables), 1 2 = ∞ (inextensible cables), 2 = 0 (flexible deck), 2 = 0 (rigid warping), 2 = ∞ (free warping), 2 = 0 (flexible deck).…”

Statistically Filtering Data for Operational Modal Analysis under Ambient Vibration in Structural Health Monitoring Systems

“…Also, Shama et al [2] conducted ambient vibration tests on North Grand Island Bridge in West New York for the FE model validation. Brown john et al [3] acquired the OMA data of the Humber Bridge in 2008 and studied the modal parameter variation from an old dataset obtained decades ago. The OMA techniques are also safe and suitable for the modal test of historical architecture.…”