Analytical and experimental investigation on the flexural behavior of partially encased composite beams

Abstract

Composite members have become popular for medium and high rise buildings. This paper presents the results of an experimental and analytical investigation of the partially-encased composite steel beams with and without web openings. The constant parameters included in this study are the cross-sectional area of the specimen, the distribution of web openings in the encased steel beam, and the grade of concrete. The variable parameters included are percentage of steel section and the presence/non-presence of web openings of the encased steel beam. Six composite beams were tested with different steel percentages. The tests were conducted by applying concentrated load acting at mid-span of each composite beam. The experimental results of encased composite beams are compared and the mode failures are discussed. Based on the testing results it was found that, the specimens with web openings provided better performance as compared to that without web openings. Also the existence of web openings in the encased steel beams is effective in enhancing the flexural capacity and the energy absorption. This increases the ductility and hence reduces the weight of structure. A nonlinear finite element analysis is presented to evaluate the flexural behavior of composite beams. The test results are also compared with the finite element software. Good correlations between what was modeled and the actual experimental results have been achieved.