Document Type : Original Article

Authors

• Ehsan Dehghani ¹
• Faezeh Heidari ²

¹ Associate Professor, Department of Civil Engineering, University of Qom, Qom, Iran.

² Master of Science in Civil Engineering, Qom University, Qom, Iran.

Abstract

Objective: In order to improve the seismic performance of structures with a bending frame system, the aim of this research is to prevent shear sliding failure at the plastic hinges of beams by changing the location of the plastic hinges.

Method: In this study, four pairs of three-dimensional finite element models, including a beam with diagonal reinforcement and a conventional beam (without diagonal reinforcement) with the same dimensions and lengths of 2, 4, 6, and 8 meters, with a floor height of 3.5 meters, have been modeled. The nonlinear behavior of steel is defined as a bar element and concrete as a volume element.

Results: The results of this research were obtained by drawing displacement force diagram for each model and key parameters such as maximum resistance, hardness, reduction of hardness and energy dissipation were extracted and compared. Also, the pattern of cracks has been investigated by tracking the values of plastic strains in the areas with maximum tensile strain in concrete.

Conclusions: The findings show that beams with diagonal reinforcement are no different from ordinary beams in terms of stiffness, but they perform better in terms of strength. Also, with increasing beam length, the stiffness and strength of beams with diagonal reinforcement have decreased, such that in a beam with a length of 2 meters, the stiffness is 62 percent higher than in a beam with a length of 8 meters. In addition, with increasing beam length from 2 meters to 8 meters, energy dissipation in beams with diagonal reinforcement has decreased by 41 percent.

Keywords

• Diagonal shear reinforcement
• finite element analysis
• beam with diagonal reinforcement
• reinforced concrete beam
• bending frame

Main Subjects

• structure