Conventional reduced beam sections (RBS) maintain their capacity with up to 4% drift angle, after which local buckling at the reduced section significantly reduces their resistance. The use of hybrid-sandwiched reduced beam sections (HS-RBS) in the reduced section of conventional RBS beams previously proposed by the authors can increase the energy absorption capacity, allowing the beam to reach 7% drift without losing capacity. The experimental results indicate that placing the HS-RBS in the reduced section of the RBS beam does not disrupt its main role in forming a plastic joint in the reduced section. HS-RBS is comprised of grout, nuts and bolts, and the sandwiching plates. In this system, the bolts and the sandwiching plate enclose the grout and the bolts are placed in the grout on two sides of the beam web in the reduced section to increase the grout's capacity to resist the tensile stresses arising from the web buckling. The sandwiching plate is located in the reduced section on two sides of the flange to enclose the grout and increase the buckling resistance of the flange. This study employed finite element modeling (FEM) to analyse beam bolts with different diameters for different sections of the HS-RBS to obtain the best diameter for each bolt. Moreover, sandwiching plates with different thicknesses were examined to find the best thickness. پرونده مقاله

The problem of overcrowding at the junction of the rebars is very significant, particularly for seismic details. Mechanical couplers can, thus offer an appealing solution that eliminates the disadvantages of traditional reinforcement splicing. By identifying the target area for bar failure, the potential area for failure could be modified with this in mind, it is very useful in assessing the position of the reinforced concrete (RC) plastic hinge. In this context, the present study focuses on the numerical and analytical modelling of the experimentally obtained response of Integrated bar (without coupler) and bars with mechanical coupler to tensile uniaxial tests. Simulation results showed agreement with the experimental response in terms of load–elongation curve, Von Mises yield and failure mode .After validating the model, alternative designs (diameter, height and thickness of mechanical couplers and bar) were numerically tested to study the influence of the geometry of the structural system on the failures mechanical coupler. Overall results indicated that the optimum design would be the one with an increased diameter in the thread area of both the bar and the mechanical coupler. For this improved configuration, the load-bearing capacity was Similar to the Integrated bar (without coupler) Cases. پرونده مقاله