Mathematical Model af a Timber Bridge Guardrail System
Abstract
A timber bridge guardrail system, subjected to static loads, was twice mathematically modeled as a beam on elastic supports. The initial model possessed uncoupled discrete spring supports representing the support provided to the guardrail by the posts. The second model contained coupled spring supports, the coupling being provided by the bridge deck structure to which the line of guardrail posts are attached. The stiffness of the spring supports for both models were determined experimentally by transversely loading each post of a timber guardrail section of a longitudinal laminated deck bridge after the guardrail member was removed. Using these stiffnesses, each model was utilized to predict the deflections of the complete test specimen (with the guardrail reattached). The first model was inaccurate, producing unacceptably large predictions of the actual deflections. The second model considerably improved the prediction of the deflected shape and magnitude of the deflections. For the representative load condition (rail loaded at center post location) the latter model yielded displacements within 13% of the measured values as compared to 34% for the former model. Keywords: Theses, Static loads, Impact loading, RAIL computer program. (KR)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA196871
Entities
People
- Mark S. Malone
Organizations
- Air Force Institute of Technology