Perfobond rib (PBL) shear connectors, made up of the perforated steel plates with the penetrating rebars passing through the holes, are extensively adopted in steel-concrete composite structures for their excellent performance. The adequate understanding of mechanical properties for PBL connectors is of great significance for their reasonable design. In this study, a push out experiment, including 12 specimens with the parameters of concrete strength, diameter of penetrating rebars and the number of holes on perforated steel plate, was performed to explore the mechanical behavior of PBL connectors with steel fiber high strength concrete (SFHSC). The experimental results showed that the shear capacity of the PBL connectors increased with the increase in concrete strength, diameter of the penetrating rebars and the number of holes. Furthermore, a general prediction formula for the shear capacity of PBL connectors was developed, which considers the shear contribution of concrete dowels, concrete end-bearing, interfacial bonding between the perforated steel plates and concrete and the penetrating rebars as well as the enhancement effect of steel fibers. The prediction results of the equation are in good agreement with the experimental data and could provide a reference for the design of PBL connectors.
This paper analyzes the stressing state characteristics of a concrete-filled steel tubular (CFST) arch model under spatial loads, using the method of modeling structural stressing state and the thin plate simulating interpolation (TSI) method. Firstly, the parameter-generalized strain energy density (GSED) is applied to model the stressing state of the arch. Then, the normalized GSED sum at each load plots the characteristic curve. The characteristic loads P (66 kN) and Q (85 kN) in the curve are distinguished by the Mann–Kendall (M–K) criterion. To characterize structural axial and bending stressing states, the parameters of the sectional average strain and generalized bending strain are proposed as stressing state submodes. Finally, the TSI method is used to interpolate strain data for deep analysis of internal forces. By modeling the structural stressing state, the working behavior characteristics of arch structures are greatly revealed in a particular view and the results could provide a reference for the development of bridge design.
This paper investigated the behavioral characteristics of two single tube concrete-filled steel tube (CFST) arch models under different loads. Applying the numerical shape function (NSF) method, the limited strain data of arch models were interpolated to obtain more detailed strain information at unmeasured points. By numerically modeling and characterizing the structural stressing state of arches, these interpolated strains were calculated as the normalized strain energy density (SED) sum to plot the corresponding characteristic curves. Utilizing the Mann-Kendall (M-K) criterion, the qualitative characteristic load was detected from the curve and was referred to as the failure load, updating the existing definition of structural failure. Then, from the perspective of experimental strains, strain/stress fields, and stressing state submodes of internal forces obtained based on the NSF method, the working behavioral characteristics of each respective CFST arch model under loads were embodied in detail. The mutation features were distinguished from the development trend of strain/stress fields or distribution patterns of internal forces to verify the rationality of the updated failure load. Consequently, the NSF method can have a reasonable interpolation on the limited experimental data. By modeling structural stressing state, it can conduct an accurate estimation of the structural failure load and provide a reference for the future design of arch bridges.