Hysteretic shear and analysis models for reinforced concrete coupling beams with small span-to-depth ratios

The force interpolation function of Modified Force-Based Fiber Element (MFBFE) contains shear force interpolation function, which is able to consider the interaction between the bending moment and the shear force at the element level. It is suitable for nonlinearly numerical simulation of coupling beams with small span-to-depth ratios (less than 2.5) governed by shear deformation. At the section level, a hysteretic shear model for coupling beams is proposed, without the assumption that the yield and maximum shear forces are equal. The envelope curve based on multi-linear model includes cracking, yielding, maximum, and failure points. Both unloading and reloading paths and pinching effect are exhibited by the proposed hysteresis rules. The code for MFBFE and the proposed hysteretic shear model called CBHShear have been implemented into OpenSees. 4 specimens are simulated using the proposed analysis model, which have different small span-to-depth ratios, longitudinal reinforcement ratios, transverse reinforcement ratios, reinforcement strength and concrete strength. The analytical results are compared with the test results, which show good agreement and verify that the model can accurately represent the nonlinear behaviors of various sizes of coupling beams. © 2018, Engineering Mechanics Press. All right reserved.