Finite-element solutions for thermal stresses in steel-concrete composite bridges
The objective was to determine experimentally and analytically steady-state temperature distributions produced in the cross-sectional planes of steel-concrete composite simple-span bridges. The upper and lower surfaces were exposed to different temperatures.
The research included the development of finite-element solutions for steady-state temperature distributions from known boundary conditions and the calculation of strains and stresses. Temperature and stress distributions were generally nonlinear with linear strains through the finite elements. Temperatures were predicted to ±1° F (±0.6° C). The experimental strains are linear through the composite section, with the computed finite-element strains generally giving slightly higher stresses.
The concrete-slab stresses were overestimated for positive curvature and slightly underestimated for negative curvature. Concrete-slab stresses were relatively small when compared to their permissible stress. Temperature stresses in the steel beam were shown to be significantly large to warrant consideration in the design of these bridges. Stresses were calculated for short-term steady-state temperatures. Transient field conditions producing greater thermal stresses are now under investigation.
KeywordsThermal Stress Temperature Stress Negative Curvature Positive Curvature Steel Beam
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- 1.Zuk, W., “Thermal and Shrinkage Stresses in Composite Beams,”ACI Journal, Proceedings,58 (3),327–340 (September1961).Google Scholar
- 2.Berwanger, C., “Thermal Stresses in Composite Bridges,” Proceedings ASCE Conference on Steel Structures, Engineering Extension Series No. 15, University of Missouri, Columbia (1970).Google Scholar
- 3.Newmark, N. M., “Numerical Procedure for Computing Deflections, Moments, and Buckling Loads,”Proceedings, ASCE 68,691–718 (1942).Google Scholar
- 4.Symko, Y., “A Study of Steady-State Heat Conduction and Deformations on Model Concrete and Composite Bridges,” M.A.Sc. Thesis, Civil Engineering Dept., University of Ottawa (December 1971).Google Scholar
- 5.Berwanger, C., andSymko, Y., “Thermal Stresses in Steel-Concrete Composite Bridges,”Canadian Journal of Civil Engineering,2 (1),66–84 (1975).Google Scholar
- 6.Standard Specifications for Highway Bridges, Adopted by the American Association of State Highway Officials, Washington, D. C., Tenth Edition (1969).Google Scholar