Dynamic structural assessment of a highway bridge via hybrid fe model and in situ testing

The first part of the paper presents a hybrid model flat shell element HFS18 for vibration analysis. The element is constructed by using simple and fast symbolic algorithms, leading to computerized analytical integrator-generator modules which optimize the process of FE generation. The element is tested against several benchmark test problems. The solutions have revealed that the present element is remarkably accurate and fast in predicting vibration modes for practical interests. The second part of the paper introduces a diagnostic scheme for structural integrity assessment of highway bridges. The scheme is based on the dynamic FE analysis and in situ testing under a moving vehicular load. The FE analysis is performed by using the HFS18 vibration element. The first 10 critical frequencies and mode shapes are computed on a desktop PC and the first 3 flexural modes are verified by the test measurements. The paper concludes that the proposed dual field database scheme can be used cost effectively for periodic monitoring and urgent assessment of bridge structures. (C) 1997 Elsevier Science Ltd.