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Pseudo Dynamic Test and Time-History Analyses of Traditional-Style Steel Frame Structures
Liangjie Qi,Jian-yang Xue 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.2
To study the seismic performances of steel frame structures in traditional-style buildings, the pseudo-dynamic test was carried out on a 1/2 ratio model built in the areas with a seismic design intensity of eight. The input earthquake waves included El Centro, Lanzhou and Wenchuan, and the maximum peak accelerations of these ground motions were 70, 200, 400 and 620 gal (0.7, 2, 4 and 6.2 m/s 2 ). The seismic responses such as displacement, reaction force, acceleration were recorded. The hysteretic behavior, energy dissipation capacity, time-history curves of acceleration and displacement, bearing capacity and stiff ness degradation were analyzed. The results show that the traditional-style steel frame structure stayed in the elastic stage subjected to no more than 400 gal (4 m/s 2 ) PGA. There was no obvious pinch phenomenon in the hysteretic loops and the structural energy dissipation increased signifi cantly with the increase of the seismic wave amplitude. When the 9-intensity seismic wave was applied, some unique members in traditional-style buildings yielded, and the spectral characteristic of the input seismic wave had a great infl uence on the seismic response of the structure. The modal analysis and time-history analyses were applied to the structure, the vertical deformation of the second and third modes of the steel frame was larger than that of the fi rst modal shape, the reaction force value of fi nite element was a little larger than that of the test under the same loading condition. When the structure subjected to more severe earthquake, some unique members in traditional-style buildings acted as the fi rst earthquake fortifi cation line and dissipate most energy, and the structural most obvious reaction took place in advance or delayed a bit.
Liangjie Zheng,Biao Ma,Man Chen,Liang Yu,Jiaqi Xue 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7
A comprehensive numerical model was proposed to investigate the disengaging process of a wet multi-disc clutch, which included the hydrodynamic lubrication, the micro elastic–plastic contact, the spline resistance, and the impact between the piston and clutch hub. The clutch disengaging process was divided into the boundary, mixed, and hydrodynamic lubrication stages to discuss the variations in friction pair gaps and friction torque. Moreover, the nonuniformity coefficient was employed to characterize the disengaging uniformity of friction pair gaps. During the disengaging process, the friction pair gaps increased slowly, increased rapidly, and stabilized after fluctuating. The increase in spline friction coefficient and the decline in pressure decrease rate dramatically deteriorated the disengaging uniformity; the decline in pressure decrease rate also significantly prolonged the disengaging time. This research demonstrated for the first time evidence for the dynamic characteristics of the clutch disengaging process.
Liangjie Qi,Jianyang Xue,Dan Xu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.5
The mechanical properties of timber construction have drawn more attention after the 2013 Lushan earthquake. A strong desire to preserve this ancient architectural styles has sprung up in recent years, especially for residential buildings of the mountainous areas. In the column-and-tie timber construction, continuous-tenon joints are the most common structural form to connect the chuanfang (similar to the beam in conventional structures) and the column. To study the cyclic performance of the continuous-tenon joints in column-and-tie timber construction, the reversed lateral cyclic loading tests were carried out on three 3/4 scale specimens with different section heights of the chuanfang. The mechanical behavior was assessed by studying the ultimate bending capacity, deformation ductility and energy dissipation capacity. Test results showed that the slippage of chuanfang occurred when the specimens entered the plastic stage, and the slippage degree increased with the increase of the section height of chuanfang. An obvious plastic deformation of the chuanfang occurred due to the mutual squeezing between the column and chuanfang. A significant pinching was observed on the bending moment-rotation curves, and it was more pronounced as the section height of chuanfang increased. The further numerical investigations showed that the flexural capacity and initial stiffness of the continuous-tenon joints increased with the increase of friction coefficient between the chuanfang and the column, and a more obvious increasing of bending moment occurred after the material yielding. The compressive strength perpendicular to grain of the material played a more significant role in the ultimate bending capacity of continuous-tenon joints than the compressive strength parallel to grain.
Qi, Liangjie,Xue, Jianyang,Zhai, Lei Techno-Press 2019 Advances in concrete construction Vol.8 No.3
This article presents a comparative study of the effect of steel layouts on the seismic behavior of transition steel-concrete composite connections, both experimental and analytical investigations of concrete filled steel tube-reinforced concrete (CFST-RC) and steel reinforecd concrete-reinforced concrete (SRC-RC) structures were conducted. The steel-concrete composite connections were subjected to combined constant axial load and lateral cyclic displacements. Tests were carried out on four full-scale connections extracted from a real project engineering with different levels of axial force. The effect of steel layouts on the mechanical behavior of the transition connections was evaluated by failure modes, hysteretic behavior, backbone curves, displacement ductility, energy dissipation capacity and stiffness degradation. Test results showed that different steel layouts led to significantly different failure modes. For CFST-RC transition specimens, the circular cracks of the concrete at the RC column base was followed by steel yielding at the bottom of the CFST column. While uncoordinated deformation could be observed between SRC and RC columns in SRC-RC transition specimens, the crushing and peeling damage of unconfined concrete at the SRC column base was more serious. The existences of I-shape steel and steel tube avoided the pinching phenomenon on the hysteresis curve, which was different from the hysteresis curve of the general reinforced concrete column. The hysteresis loops were spindle-shaped, indicating excellent seismic performance for these transition composite connections. The average values of equivalent viscous damping coefficients of the four specimens are 0.123, 0.186 and 0.304 corresponding to the yielding point, peak point and ultimate point, respectively. Those values demonstrate that the transition steel-concrete composite connections have great energy dissipating capacity. Based on the experimental research, a high-fidelity ABAQUS model was established to further study the influence of concrete strength, steel grade and longitudinal reinforcement ratio on the mechanical behavior of transition composite connections.
Transfer zones within the Longmen Mountains thrust belt, SW China
Wenzheng Jin,Liangjie Tang,Keming Yang,Guimei Wan,Zhizhou Lü,Yixin Yu 한국지질과학협의회 2009 Geosciences Journal Vol.13 No.1
The Longmen Mountains thrust belt contains complex structures resulting from multi-phase tectonic movements. Field investigations and interpretations of seismic profiles reveal two important transfer zones in the thrust belt: the Anxian and Guanxian transfer zones. Many thrust and strike-slip faults are found in the shallow part of the transfer zones, and duplexes and detachment structures in the deep part. The Anxian transfer zone is located between the Jiaoziding and Jiudingshan nappes, consisting mainly of the Lower Triassic Feixianguan Formation (T1 f ) and Jianglingjiang Formation (T1 j), and Middle Triassic Leikoupo Formation (T2l). The Guanxian transfer zone is located between the Baoxing and Jiudingshan nappes, consisting mainly of Devonian, Carboniferous, Triassic, Jurassic, and Presinian rocks. This zone contains many thrust faults, strike-slip faults, and duplexes in its deeper part (where early structures have been almost completely overprinted), and many klippens are found at the surface.
Concrete-steel bond-slip behavior of recycled concrete: Experimental investigation
Rui Ren,Liangjie Qi,Jian-yang Xue,Xin Zhang,Hui Ma,Xiguang Liu,Togay Ozbakkaloglu 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.3
In order to study the interfacial bond-slip behavior of steel reinforced recycled concrete (SRRC) under cyclic loading, thirteen specimens were designed and tested under cyclic loading and one under monotonic loading. The test results indicated that the average bond strength of SRRC decreased with the increasing replacement ratio of recycled concrete, whereas the bond strength increased with an increase in the concrete cover thickness, the volumetric stirrup ratio, and the strength of recycled concrete. The ultimate bond strength of the cyclically-loaded specimen was significantly (41%) lower than that of the companion monotonically-loaded specimen. The cyclic phenomena also showed that SRRC specimens went through the non-slip phase, initial slip phase, failure phase, bond strength degradation phase and residual phase, with all specimens exhibiting basically the same shape of the bond-slip curve. Additionally, the paper presents the equations that were developed to calculate the characteristic bond strength of SRRC, which were verified based on experimental results.
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.
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.
Sairong Zhu,Yong Yin,Liangjie Bi,Zhiwei Chang,Che Xu,Fanbo Zeng,Ruibin Peng,Wen Zhou,Bin Wang,Hailong Li,Lin Meng 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.9
A method aimed at improving the beam-wave interaction eciency by changing the coupling slot configuration has been proposed in the study of extended interaction oscillators (EIOs). The disper- sion characteristics, coupling coecient and interaction impedance of the high-frequency structure based on different types of coupling slots have been investigated. Four types of coupled cavity structures with different layouts of the coupling slots have been compared to improve the beam- wave interaction eciency, so as to analyze the beam-wave interaction and practical applications. In order to determine the improvement of the coupling slot to a coupled cavity circuit in an EIO, we designed four nine-gap EIOs based on the coupled cavity structure with different coupling slot configurations. With different operating frequencies and voltages takes into consideration, beam voltages from 27 to 33 kV have been simulated to achieve the best beam-wave interaction eciency so that the EIOs are able to work in the 2 mode. The in uence of the Rb and the ds on the output power is also taken into consideration. The Rb is the radius of the electron beam, and the ds is the width of the coupling slot. The simulation results indicate that a single-slot-type EIO has the best beam-wave interaction eciency. Its maximum output power is 2.8 kW and the eciency is 18% when the operating voltage is 31 kV and electric current is 0.5 A. The output powers of these four EIOs that were designed for comparison are not less than 1.7 kW. The improved coupling-slot con- gurations enables the extended interaction oscillator to meet the different engineering requirements better.