Experimental and analytical investigation into crack strength determination of infilled steel frames

This paper presents the results of further development of a new analytical approach for the evaluation of shear strength and cracking patterns of infill panels. This method is based on the minimum evaluated strength with reference to the failure surfaces. This paper also presents the results of an experimental investigation of small and medium scale masonry and concrete infilled frames. Eleven specimens, with and without horizontal reinforcement and bond beams, were subjected to static cyclic loads. The tests are categorized in two groups, based on their surrounding frames and scale. In the first group a small scale factor is used, and the frames have pinned connections with very stiff beams and columns representing the lower stories of tall buildings. In the second group a medium scale factor is used, and the frames have rigid connections.Both experiments and analysis have confirmed that the efficiency of horizontal reinforcement and bond beams depends on the dominant pattern of cracking. The results also indicate that as opposed to masonry infills, the corner crushing is the dominant mode of failure in concrete infills.