دانلود رایگان مقاله انگلیسی رفتار لرزه ای اتصالات پایه پیچ خورده بین دیوار بتن آرمه از جنس فولاد (SRC) و میله SRC - اشپرینگر 2018

Abstract

To improve the constructability of the steel and concrete composite coupled wall system while maintaining good seismic performance in terms of strength, stiffness and energy dissipation capacity, the bolted endplate connection between steel reinforced concrete (SRC) wall and SRC beam has been proposed and studied. The endplate is shop welded to the end of steel beam and then fastened to the flange of steel column at boundary element of wall pier through high-strength bolts before the fabrication of reinforcement cage and concrete pouring for the composite beams. Five SRC beam-SRC wall subassembly specimens were designed, constructed and tested subjected to cyclic displacement reversals at SRC beam end. The test parameters included the amount of steel plate embedded in SRC beams and the influence of slab. The responses of the specimens in terms of load–displacement hysteretic responses, cracking patterns, ductility, strength and stiffness degradation characteristics were discussed. The test results show that through rational design the bolted endplate connection can satisfactorily ensure the load transfer mechanism between SRC beam and SRC wall such that the SRC beam can fully develop its strength, ductility, post-yield strength and stiffness retention capacities. The strength, post-yield deformation and energy dissipation capacity of SRC coupling beams can be effectively enhanced by increasing the steel plate ratio. The existence of slab can enhance the overall seismic performance of SRC beam. Nonlinear finite element modeling approach was developed and verified by comparison with the test results, showing good agreement in terms of the skeleton and hysteresis curves.

4 Conclusions

The seismic performance of bolted endplate connections between steel and concrete SRC coupling beams to SRC shear walls was examined by experimental investigation and finite element numerical simulation. Based on the experimental observations and results from numerical studies, the following conclusions can be drawn:

1. The existence of slab can improve the strength, initial stiffness and ductility of SRC beam-wall subassembly with bolted endplate connection. No matter the slab influence is considered or not in design, the resulted SRC beams shall possess higher strength than expected in design. It is reasonable to design the beam-wall joint based on 1.6 times the nominal beam capacity.

2. Increasing the steel plate ratio for SRC coupling beam can effectively enhance the strength, stiffness and ductility. In addition, the energy dissipation capacity of the SRC beam can be significantly improved using a steel plate ratio of 5%.

3. The bolted endplate connection can be designed to satisfactorily ensure the SRC coupling beams to develop their strength, deformation and energy dissipation capacities. Although cracks will be developed in the early loading stage, the post-yield inelastic damages will be concentrated to the SRC beam. 4. The hysteretic curves and skeleton curves simulated by the finite element analysis agreed well with those obtained in experiments, showing the effectiveness and accuracy of the suggested numerical techniques.