Analyzing pre-stressed steel arch beams

Abstract

Techniques are being developed day-by-day to make it possible to pass through larger openings using smaller beam-column sections. Parallel to this trend, there is another necessity to produce not only smaller but also more economical and architecturally attractive beams. The aim of this study is to explain the structural behavior of steel arch beams reinforced using post-tension cables. Due to the effect of these, the arch beam load carrying capacity increases and a smaller sized optimized section can be obtained with a better architectural view. Moreover, it also allows better mechanical and applicable solutions for buildings. For a better understanding of the behavior of the reinforced beam, a steel beam and a steel arch beam with post-tensioned cables were modeled and analyzed using the SAP2000 finite element analysis computer program and compared with each other. In addition, full-scale specimens were prepared for testing to determine the structural behavior and compare the results with those from the computer modeling, the outcome of which was very promising. The similarity between the results inferred that no extra engineering knowledge and effort are needed to design such beams. The predicted (and proved by the testing) beam bearing capacity was 35% higher than that of the unreinforced beam. With just three full-scale tests completed, it was evident that the ratio (35%) could be increased by adjusting the cable post-tension force on much smaller sized beams.