圆形钢-混凝土组合梁板静力性能试验研究OA北大核心

In order to study the static performance of circular steel-concrete composite beam-slab with radial steel beams,the center single-point static loading tests of four simply supported specimens were conducted.The variation parameters were the number of beams and the configuration of center node.The failure modes,load-displacement curves,strain distribution of concrete slabs and steel beams were studied.The results show that under the single-point loading,the specimens go through elastic stage,elastoplastic stage,plastic development stage and stepped failure stage,and present the characteristics of bending failure.The main failure modes include tension cracking of the weld of lower flanges of steel beams and penetration of the main cracks of concrete slabs.The structures have high bearing capacity and good ductility,with the ultimate loads between 565.8 kN and 1 338.4 kN and displacement ductility coefficients between 4.12 and 8.69,and the limit flexural span ratios are between 1/71 and 1/35.The safety redundancy is high because the tension cracking of one steel beam does not lead to a significant decrease in bearing capacity.The center nodes are not weak part.With the increase in the number of beams,the restraint of steel beams on concrete is enhanced,and the maximum stress positions of lower flanges are shifted along the beams from center to supports.The formulas for calculating the yield and ultimate loads of circular steel-concrete composite beam-slab structures were proposed,and the calculation results agree well with experimental results.