Experimental study on all-bolted joint in modularized prefabricated steel structure

Zhanjing Wu,Zhong Tao,Bei Liu,Heng Zuo 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.6

The research study is focuses on a form of all-bolted joint with the external ring stiffening plate in the prefabricated steel structure. The components are bolted at site after being fabricated in the factory. Six specimens were tested under cyclic loading, and the effects of column axial compression ratio, concrete-filled column, beam flange sub plate, beam web angle cleats, and spliced column on the failure mode, hysteretic behavior and ductility of the joints were analyzed. The results shown that the proposed all-bolted joint with external ring stiffening plate performed high bearing capability, stable inflexibility degradation, high ductility and plump hysteretic curve. The primary failure modes were bucking at beam end, cracking at the variable section of the external ring stiffening plate, and finally welds fracturing between external ring stiffening plate and column wall. The bearing capability of the joints reduced with the axial compression ratio increased. The use of concrete-filled steel tube column can increase the bearing capability of joints. The existence of the beam flange sub plate, and beam web angle cleat improves the energy dissipation, ductility, bearing capacity and original rigidity of the joint, but also increase the stress concentration at the variable section of the external reinforcing ring plate. The proposed joints with spliced column also performed desirable integrity, large bearing capacity, initial stiffness and energy dissipation capacity for engineering application by reasonable design.

Experimental Performance of Recycled Aggregate Concrete-filled Square Steel Tubular (RACSST) Stub Columns After Exposure to High Temperature and Water Spraying Cooling

Zhanjing Wu,Xiaojun Ke,Yisheng Su 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.3

In order to study the mechanical properties of Recycled Aggregate Concrete-fi lled Square Steel Tubular (RACFSST) stub columns after fi re exposure, a total of 37 specimens were exposed to heating temperatures and cooling phases (including natural cooling and water spray cooling), and the axial compression tests were subsequently conducted. The failure modes, axial load versus deformation curves, and residual bearing capacity of specimens with diff erent cooling methods were obtained. The results show that all specimens suff ered steel tube tearing and local buckling. The overall change law of the axial load versus displacement curves was signifi cantly aff ected by the heating temperature and cooling method, whereas not obviously aff ected by the replacement ratio of RCA. Compared with natural cooling, the residual bearing capacity of specimens decreased after water spray cooling, with a maximum decrease of 38.17%. A simplifi ed formula for calculating the residual bearing capacity which can take into account the infl uence of RAC ratio, heating temperature, and cooling method of reclaimed aggregate was proposed.

Seismic Performance of Steel Joints Between Double Beams and Column in Chinese Traditional Style Buildings

Jian-yang Xue,Linlin Ma,Zhanjing Wu 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.2

This paper presents experimental study and fi nite-element analysis (FEA) on seismic performance of steel joints between double beams and column (DBC) in Chinese traditional style buildings. Eight 1/2-scaled DBC joints were designed according to the principle of “strong-member and weak-joint” and tested under low cyclic reversed loading. The failure modes, hysteresis loops, skeleton curves, ductility and energy-dissipation capacity of the joints were analyzed. It is shown that the failure modes of the joints were shear buckling at lower panel zone, bending failure at middle panel zone, and welds fracturing at the panel zone of the joints. The section types of beams, axial compression ratio, and joint forms between double beams and column had signifi cant impacts on the bearing capacity of the joints. The bearing capacity of the joints decreased as the axial compression ratio increased. Moreover, the bearing capacity of the joints with box beams was larger than that of the joints with H-section beams. Elaborate FEA models of the joints were presented, and a preliminary FEA was fi rst performed to predict the mechanical properties and hysteretic behaviors of the joints. The results of FEA were correlated well with those of test, and the eff ect of the panel zone thickness on mechanical behaviors of the joints was analyzed, which indicated that the simplifi ed FEA model could provide a powerful tool for future research in design methods of DBC joints in Chinese traditional style buildings.

Experiment and bearing capacity analyses of dual-lintel column joints in Chinese traditional style buildings

Jian-yang Xue,Linlin Ma,Zhanjing Wu,Lei Zhai,Xin Zhang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.5

This paper presents experiment and bearing capacity analyses of steel dual-lintel column (SDC) joints in Chinese traditional style buildings. Two SDC interior joints and two SDC exterior joints, which consisted of dual box-section lintels, circular column and square column, were designed and tested under low cyclic loading. The force transferring mechanisms at the panel zone of SDC joints were proposed. And also, the load-strain curves at the panel zone, failure modes, hysteretic loops and skeleton curves of the joints were analyzed. It is shown that the typical failure modes of the joints are shear buckling at bottom panel zone, bending failure at middle panel zone, welds fracturing at the panel zone, and tension failure of base metal in the heat-affected zone of the joints. The ultimate bearing capacity of SDC joints appears to decrease with the increment of axial compression ratio. However, the bearing capacities of exterior joints are lower than those of interior joints at the same axial compression ratio. In order to predict the formulas of the bending capacity at the middle panel zone and the shear capacity at the bottom panel zone, the calculation model and the stress state of the element at the panel zone of SDC joints were studied. As the calculated values showed good agreements with the test results, the proposed formulas can be reliably applied to the analysis and design of SDC joints in Chinese traditional style buildings.

Dynamic experimental study on single and double beam-column joints in steel traditional-style buildings

Xue, Jianyang,Qi, Liangjie,Yang, Kun,Wu, Zhanjing Techno-Press 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.5

In order to study the failure mode and seismic behavior of the interior-joint in steel traditional-style buildings, a single beam-column joint and a double beam-column joint were produced according to the relevant building criterion of ancient architectural buildings and the engineering instances, and the dynamic horizontal loading test was conducted by controlling the displacement of the column top and the peak acceleration of the actuator. The failure process of the specimens was observed, the bearing capacity, ductility, energy dissipation capacity, strength and stiffness degradation of the specimens were analyzed by the load-displacement hysteresis curve and backbone curve. The results show that the beam end plastic hinge area deformed obviously during the loading process, and tearing fracture of the base metal at top and bottom flange of beam occurred. The hysteresis curves of the specimens are both spindle-shaped and plump. The ultimate loads of the single beam-column joint and double beam-column joint are 48.65 kN and 70.60 kN respectively, and the equivalent viscous damping coefficients are more than 0.2 when destroyed, which shows the two specimens have great energy dissipation capacity. In addition, the stiffness, bearing capacity and energy dissipation capacity of the double beam-column joint are significantly better than that of the single beam-column joint. The ductility coefficients of the single beam-column joint and double beam-column joint are 1.81 and 1.92, respectively. The cracks grow fast when subjected to dynamic loading, and the strength and stiffness degradation is also degenerated quickly.

Dynamic experimental study on single and double beam-column joints in steel traditional-style buildings

Jian-yang Xue,Liangjie Qi,Kun Yang,Zhanjing Wu 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.5

In order to study the failure mode and seismic behavior of the interior-joint in steel traditional-style buildings, a single beam-column joint and a double beam-column joint were produced according to the relevant building criterion of ancient architectural buildings and the engineering instances, and the dynamic horizontal loading test was conducted by controlling the displacement of the column top and the peak acceleration of the actuator. The failure process of the specimens was observed, the bearing capacity, ductility, energy dissipation capacity, strength and stiffness degradation of the specimens were analyzed by the load-displacement hysteresis curve and backbone curve. The results show that the beam end plastic hinge area deformed obviously during the loading process, and tearing fracture of the base metal at top and bottom flange of beam occurred. The hysteresis curves of the specimens are both spindle-shaped and plump. The ultimate loads of the single beam-column joint and double beam-column joint are 48.65 kN and 70.60 kN respectively, and the equivalent viscous damping coefficients are more than 0.2 when destroyed, which shows the two specimens have great energy dissipation capacity. In addition, the stiffness, bearing capacity and energy dissipation capacity of the double beam-column joint are significantly better than that of the single beam-column joint. The ductility coefficients of the single beam-column joint and double beam-column joint are 1.81 and 1.92, respectively. The cracks grow fast when subjected to dynamic loading, and the strength and stiffness degradation is also degenerated quickly.