IMPACT FORMULAS FOR VEHICLES MOVING OVER SIMPLE AND CONTINUOUS BEAMS

The authors of this technical paper develop new impact formulas for simple and continuous beams subjected to moving vehicle loads. By modeling a vehicle as spring masses and a bridge structure by beam elements, a parametric study is conducted for various simple and continuous beams traversed by five-axle trucks. The study emphasizes the adoption of a nondimensional speed parameter, which is defined as the ratio of the driving frequency of the vehicle represented by an equation denoting the velocity of the vehicle and the characteristic length of the beam to the fundamental frequency of the beam. From numerical computation, the authors conclude that the impact factors for the deflections, bending moments, and shear forces at the midpoints of simple beams are linearly proportional to the speed parameter. These formulas can be multiplied by certain modification factors to yield results for continuous beams and support shears. Vehicle/bridge frequency ratio, damping of the bridge, and road surface roughness are other parameters examined.

Language

  • English

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Filing Info

  • Accession Number: 00712788
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 28 1995 12:00AM