Search

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The shear steel plate damper is used as a good seismic energy dissipation device. However, the existing researches mainly focus on the situation of shear unidirectional force, and the research on the state of bidirectional force is still insufficient, such as the applications on underground structures and energy dissipation connected beams, and so on. Some researches show that ordinary shear plate dampers are prone to out-of-plane buckling easily, even more applying additional axial forces, the seismic performance is poor. To address this issue, an experimental study on the hysteretic behavior of buckling restrained shear plate dampers ( BRSPDs) with flanges, is carried out under bidirectional loadings of shear force and axial force. In this paper, three groups of specimens are set up. To investigate the effect of axial force on the hysteretic performance of BRSPDs, they were subjected to horizontal reciprocating loading tests under different axial forces. In addition, a total of 7 specimens with different axial compression ratios were set up to perform finite element simulation analysis using ABAQUS. The results indicate that under the action of axial force, BRSPDs can effectively slow the external buckling of the web, and it is concluded that the maximum axial pressure ratio that this damper can work effectively is 0. 6. When the axial pressure ratio is within 0. 6, the damper shows a good energy dissipation performance and good ductility. However, when it exceeds 0. 6, the ultimate bearing capacity, ductility and energy consumption of the dampers will be severely reduced. While the stiffness of the damper has almost no changes. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the seismic performance of reinforced concrete frame structures, the buckling restrained steel plate shear wall (BRSPSW) is used as lateral load resisting and energy dissipation component to form a new type of hybrid structure. The hysteretic performance of reinforced concrete frame with BRSPSW was studied by cyclic loading test and finite element simulation of two two-storey and one-bay specimens in terms of the loading process, failure mode, energy dissipation capacity, stiffness degradation and capacity degradation, etc. The research results indicate that reinforced concrete frame with BRSPSW has excellent seismic performance. BRSPSW greatly enhances the lateral stiffness, yield capacity, energy dissipation capacity, ductility and redundancy of reinforced concrete frame structure. The energy dissipation coefficient and ductility coefficient of specimens are about 2.0 and 10.0, which are far greater than those of reinforced concrete frame structure. Furthermore, the hysteretic model of BRSPSW is proposed in order to simplify the finite element analysis. Comparison with the test results indicates that the hysteretic model can simulate the loading behavior of the test specimen with reasonable accuracy, and can be used in the nonlinear dynamic elasto-plastic analyses of this kind of structures. [ABSTRACT FROM AUTHOR]

In order to research the in-plane hysteretie behavior of cold-formed steel floor, in-plane cyclic loading tests of three full scale models of cold-formed thin-walled steel composite floors with different patterns of floor panel were earned out. The three models were profiled steel sheet composite floor, profiled steel sheet-gypsum based self-leveling mortar composite floor and profiled steel sheet-gypsum based self-leveling mortar composite floor with wire mesh. The failure mode, hearing capacity and ductility as well as bond behavior of floors were investigated. Experimental results show that the failure mode of specimen is the shear failure of the self-drilling screws connecting corrugated metal deck to end joists. Only minor damages occur to the gypsum based self-leveling mortar floor panel and middle CFS joists. The three floor specimens show good in-plane mechanical behavior in terms of hearing capacity, stiffness, energy dissipation and ductility. The overall working performance of the cold-formed thin-walled steel-gypsum based self-leveling mortar composite floor is exceptional. The application of wire mesh can improve the in-plane stiffness, bonding properties and crack resistance of composite slabs. However, it has negative influence on ductility of floor. [ABSTRACT FROM AUTHOR]

A new type joint with ring ribs was proposed to improve the structural and mechanical characteristics of tubed reinforced concrete columns, and axial load behavior and seismic behavior of the joints were investigated. Two tubed reinforced concrete columns and one joint with ring ribs were tested to investigate the axial load behavior. The test results indicate that the ring ribs of the joint can effectively constrain the shear deformation of the core concrete. Compared to the columns, the joint shows higher bearing capacity and better ductility. Besides, one conventional joint and two joints with ring ribs were tested to investigate the hysteretie behavior. Under the approximately same stirrup ratios of the joint regions, the conventional joint shows shear failure of joint region and the joins with ring ribs shows flexural failure of reinforced concrete beam. For the joints with ring ribs, the ring ribs can constrain the joint core and the concrete cover effectively, so the philosophy of 4 strong-joint and weak-member' can be achieved easily due to the more reasonable mechanical mechanism. [ABSTRACT FROM AUTHOR]

To experimentally evaluate the composite effect on the cyclic performance of weak-axis column bending connections, ten cruciform joint specimens were tested under reversal of loads, including five bare steel joint (SJ) specimens and five steel-concrete composite joint (CJ) specimens reinforced with partial shear connection. The form of beam-end was designed with standard, reduced, plate covered, widened flange, and welded haunch, respectively. The experimental phenomenon, failure mode, hysteretic curves, strain and stress distribution of steel beam and energy dissipation capacity of each specimen were analyzed and discussed. The results show that beam bottom flange welds of CJ crack in different degrees except the haunch specimen, while the beam top flange welds and web bolts could continue to bear large loads. However, beam top and bottom flange welds of SJ crack, resulting in the abrupt strength degradation. The hysteretic curves of SJ are plumper than that of CJ, since the shape of hysteretic curves of CJ gradually becomes anti S due to the influence of web bolts slippage. The neutral axis of CJ cross-section exhibits a significant upward shift under positive bending, thus developing a larger strain in the bottom flange than that of SJ. The plastic hinge can effectively move away from the column-to-beam connection in the reduced specimens, which have the most stable and reliable cyclic response, thus this joint form is recommended first. The welding quality is the key factor which could influence the hysteretic behavior of joints, and lamellar tearing resistant steel is suggested to be used in skin plates. [ABSTRACT FROM AUTHOR]

In order to study the mechanical performance of prefabricated steel tube column joints using high-strength bolted flange connection with tapping steel plate in multistory steel frame structures, the static tests and the quasi-static tests of full scale models were conducted. The load bearing capacities, failure modes, and hysteretic properties under one-way seismic action were obtained. The experimental study shows that the static test specimens have high bearing capacity. The failure mode is the short column yielding on the compression side. The quasi-static test specimens have full hysteresis curves, good ductility, and excellent energy dissipation characteristics. The failure mode is the short column yielding. In addition, the mechanical performance of this kind of column joints was analyzed using finite element numerical analog analysis method. Simulation results are in good agreement with the experiment. Comparing the finite element analysis results of rigid connection model and bolted connection model, this kind of column joints could be regarded as equivalent rigid connection in practical engineering application. [ABSTRACT FROM AUTHOR]

In order to research the seismic performance of double steel plate-concrete coupled composite shear walls with replaceable link, the test on the one-bay two-story and half story specimen at one-third scale was carried out under low-cycle reversed loading and the links were replaced twice. The failure mechanism, hysteretic behavior, ductility, rigidity degeneration and energy-dissipation of specimen were analyzed. Experimental studies and analysis show that the links of coupled steel plate-concrete composite shear walls first enters the plastic energy dissipation under horizontal load. After links were replaced the seismic performance of specimens can recover to the former performance levels. If the link end plate thickness selection is reasonable and the end plate remains elastic, the links can be removed and installed easily. The steel column bases cross section should be increased appropriately and the weld of column bases connection should be carefully designed in order to avoid stress concentration. The hysteretic curve of coupled steel plate-concrete composite shear walls with replaceable link is full and has good seismic performance. When the links are replaced before and after, the difference of skeleton curves of the specimens is very small, and the structural lateral stiffness is basically identical. After the specimen enters the plastic stage, the bearing capacity of the specimen is reduced very small at the same displacement. Under the same horizontal load the shear stress of the link is the largest, the normal stress of side column bases is second largest, and the steel beam, the middle column and shear wall steel stress is the smallest. [ABSTRACT FROM AUTHOR]

In order to improve the efficiency in the assembly and construction of light-gauge slotted steel stud enclosing walls, connections between such enclosing walls and steel frames have been proposed to make sure that the wall can be fully pre-assembled and the entire wall system can be hoisted and out-hung to the steel frame on site. Using self-drilling screws or long hex bolts as the connectors between enclosing walls and steel frames, five wall elements with different wall thicknesses which were out-hung to the full-scale steel frame were tested to investigate the reliability of the connections subjected to wind compression and wind suction loading. Using ABAQUS, solid finite element models were built to investigate the stress states in connection for enclosing walls with different thicknesses and subjected to wind compression and wind suction loading, and how the loading transfers from walls to the steel frame after the validation of the reliability of the finite element model. Hysteretic experiments were then carried out on two full-scale steel frames with 3m x 3m enclosing walls to further investigate the reliability of the connections under earthquake. One of the full-scale wall specimens had window opening with the ratio of the window opening area to the wall area equal to 0.3. It has been concluded that using self-drilling screw the connection is not safe when subjected to wind suction loading, while long hex bolts are suggested to be used as the connectors when the enclosing wall is out-hung to the steel frame due to the clear loading transfer path and the ease in construction. Using long hex bolts, the materials of the connection do not yield at the failure of the walls to wind loading or in-plane horizontal loading, and no local buckling or other kinds of sudden failure occurs in connection parts. For the enclosing walls with commonly used thickness, the connectors are safe enough and can meet the design theory of 'strong member while stronger connection'. [ABSTRACT FROM AUTHOR]

By quasi-static reversed cyclic test on four hollow tubular steel braces and four concrete-filled tubular steel braces, it was examined the effect of cross-section shape, width-thickness ratio (w0/t ratio)，and concrete-filled on the seismic behavior and fracture ductility of tubular steel braces. The test results show that fracture ductility of a square tube brace is relatively small since its corner material property has been changed by cold extruding，and circular tube braces were recommended. Brace members with smaller w0/t ratio have higher local stability, and limits on maximum w0/t ratios of tubular steel braces have been suggested. Some test data has been collected to compare with the proposed formula. Concrete-filled is found to increase the initial stiffness and compressive capacity of the brace before overall buckling taking place. It is also found to enlarge deformation concentration at the middle span and lead to earlier fracture especially for square tube braces which has weaker confinement to inner concrete. Hollow ones are recommended for tubular steel braces with low w0/1 ratio. [ABSTRACT FROM AUTHOR]

The concept of high strength moment resisting frames with energy dissipation beams of carbon mild steel is proposed to realize the goal of gradual development of damages and controllable residual deformation, the seismic behavior of the proposed system was investigated by experimental research and analysis. The design concept and the load bearing behavior of the system were clarified, and then a large scale hysteretic experiment considering a spatial steel moment resisting frame was designed and performed. Prototype structures with various design parameters were designed, and the performance was evaluated by pushover analysis and nonlinear dynamic analysis. The design criterion was also proposed. Results indicate that the proposed system shows noteworthy features including the controllable yielding sequence，the development of energy dissipation mode，the transformation of hysteretic behavior and small residual story drift. The satisfactory performance of the proposed system is verified by numerical analysis. The proposed system can provide reference for the application of high strength steel components in seismic resistant structures. [ABSTRACT FROM AUTHOR]

In order to study the influence of spatial effect on panel zone hysteresis behavior and stability, four spatial H-shaped beam-column subassemblies with different connection details were designed and tested. The specimens were subjected to constant axial load and vertical loads on beams in two directions including anti-symmetric constant loads on beams perpendicular to column's weak axis and anti-symmetric cyclic loads on beams perpendicular to column's strong axis. The experimental results confirm that the recommended method based on the study of planar interior beam-column connections for evaluating the effect of vertical connecting plates on panel zone stability is still applicable. The unbalanced moments from the beams perpendicular to column's weak axis are transferred through vertical connecting plates and horizontal continuity plates, and finally earned by column flanges within the connection. If the load path is continuous and no premature yielding of elements surrounding the panel zone occurs, the panel zone will not resist the spatial loads directly. At the stress level adopted in this research, the performance of spatial specimens with reasonable constructional details is generally no worse than the corresponding planar ones in strength, deformation capacity, stability and energy dissipation capacity. [ABSTRACT FROM AUTHOR]

For developing a new type of lightweight dampers which apply to vibration control of spatial structures，six innovative buckling-restrained braces (BRBs) were fabricated with Chinese aluminium alloy, and a series of quasi-static tests were conducted to address the energy dissipation behavior of the aluminum alloy BRBs (ALBRBs). All of specimens were designed with the stability theory of BRB member, resulting in that stable hysteretic loops were obtained without overall buckling occurrence. The brace member was sandwiched by the restraining members and small gaps in between, which was filled with lithium lubricating grease to reduce the friction and hooping effect. The experimental results show that the ALBRBs always can yield without buckling both in compression and tension, the strain hardening of aluminium alloy core is very obvious and the hysteretic loops are very full and stable, thus the energy dissipation capacity is good. The non-uniformity factor between peak pressure and peak tension is no more than 1.3. Based on the Chaboche plastic constitutive model for steel，the material parameters of aluminium alloy constitutive model were obtained from experimental data which can be used for finite element analysis. The results of finite element analysis are similar to the results of the experiment. It is expected that the model parameters can be further developed for calculating the response of structures under earthquake. [ABSTRACT FROM AUTHOR]