Fatigue Damage of Steel Bridges Due to Dynamic Vehicle Loads |
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Authors: | Colin MacDougall Mark F Green Scott Shillinglaw |
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Affiliation: | 1Assistant Professor, Dept. of Civil Engineering, Ellis Hall, Queen’s Univ., Kingston ON, Canada K7L 3N6. 2Professor, Dept. of Civil Engineering, Ellis Hall, Queen’s Univ., Kingston ON, Canada K7L 3N6. 3Design Engineer, Halsall Associates, Ottawa ON, Canada K2P 0Y6.
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Abstract: | This paper focuses on the fatigue damage caused in steel bridge girders by the dynamic tire forces that occur during the crossing of heavy transport vehicles. This work quantifies the difference in fatigue life of a short-span and a medium-span bridge due to successive passages of either a steel-sprung or an air-sprung vehicle. The bridges are modeled as beams to obtain their modal properties, and air-sprung and nonlinear steel-sprung vehicle models are used. Bridge responses are predicted using a convolution method by combining bridge modal properties with vehicle wheel forces. A linear elastic fracture mechanics model is employed to predict crack growth. For the short-span bridge, the steel-sprung vehicle caused fatigue failure up to 6.5 times faster than the air-sprung vehicle. For the medium-span bridge, the steel-sprung vehicle caused fatigue failure up to 277 times faster than the air-sprung vehicle. |
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Keywords: | Structural dynamics Fatigue life Trucks Bridges steel Crack propagation Dynamic loads |
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