Dynamic stress analysis for fatigue damage prognosis of long-span bridges

Abstract

For fatigue damage prognosis of a long-span steel bridge, the dynamic stress analysis of critical structural components of the bridge under the future dynamic vehicle loading is essential. This paper thus presents a framework of dynamic stress analysis for fatigue damage prognosis of long-span steel bridges under the future dynamic vehicle loading. The multi-scale finite element (FE) model of the bridge is first developed using shell/plate elements to simulate the critical structural components (local models) and using beam/truss elements to simulate the rest part of the bridge (global model). With the appropriate coupling of the global and local models, the multi-scale FE model can accurately capture simultaneously not only the global behavior in terms of displacement and acceleration but also the local behavior in terms of stress and strain. A vehicle traffic load model is then developed for forecasting the future vehicle loading based on the recorded weigh-in-motion (WIM) data and using the agent-based traffic flow microsimulation. The forecasted future vehicle loading is finally applied on the multi-scale model of a real long-span cable-stayed bridge for dynamic stress analysis and fatigue damage prognosis. The obtained results show that the proposed framework is effective and accurate for dynamic stress analysis and fatigue damage prognosis.

Keywords:

• Multi-scale FE model
• long-span steel bridge
• future dynamic vehicle loading prediction
• dynamic stress analysis
• fatigue damage prognosis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The works described in this paper are financially supported by the Hong Kong Research Grants Council through its competitive grants (GRF 15218414), to which the authors are most grateful. Any opinions and conclusions presented in this paper are entirely those of the authors.