Abstract: Dovetail profiled steel concrete sandwich composite members (DPSC) are composed of two dovetail profiled steel sheets and filled concrete in between. The dovetail-shaped profiled ribs embedded in concrete can not only function as connectors for steel sheets and concrete, but also effectively reduce the steel sheet's width to thickness ratio and improve the buckling capacity of steel sheet. Compared with the traditional double steel plate concrete composite member, the steel sheets and concrete of DPSC can work together without additional connectors, which increases the convenience and efficiency of construction, while maintaining the performance advantages of double steel plate concrete composite member, and has a broad application prospects in engineering.
The mechanical response of the DPSC subjected to axial compression is analyzed by employing finite element method, the stress distribution of concrete section, the stress development process and the buckling behavior of the steel strips between ribs. Based on the above analysis, the embedment effect of rib in concrete is clarified. Finally, the influence of the positioning of the steel ribs, concrete strength grades, steel strength, sheet thickness (strip width to thickness ratio) and width of the members on axial compression performance of DPSC is analyzed.
The following conclusions can be drawn through the analysis:the dovetail-shaped ribs divide the steel sheets into several strips to bear the axial compression load, and each strip develops the compression buckling wave independently, which changes the overall compression buckling mode of the steel plate; the infill concrete provides enough anchorage for the ribs to realize the composite action and make the steel sheets and concrete working together; the anchored ribs offer solid boundary support and anchorage for the steel strips, which lead the strips to full development of post-buckling strength; the post-buckling strength of the strips shall be considered in calculation of the DPSC bearing capacities; the anchored dovetail-shaped ribs, under axial compression, affect the concrete stress distribution nearby and cause some confinement for the concrete between two ribs, but there are no obvious constrained region and unconstrained region; the DPSC axial compressive bearing capacities can be evaluated by the summation of the concrete compressive capacity, steel ribs reaching yielding and the post-buckling strength of strips; the parameter analysis results show that the positioning of the steel ribs has no significant effect on the axial compression bearing capacity of the DPSC, however, the material strength, wall thickness and profiled steel plate thickness have significant effects on the axial compression bearing capacity and ductility.