钢幕墙“POSN STEEL WALL”结构性能试验及评价

玻璃装饰外墙的幕墙具有外观华丽、施工维护方便等优点,目前得到了广泛应用。作为幕墙外墙的玻璃框架,主要采用重量轻、加工方便的铝材制作。韩国钢制幕墙(POSN STEEL WALL)由高耐腐蚀性合金镀层钢板制作而成,具有优异的结构性能,可承受压缩、拉伸和弯曲载荷,无需加固即可安装,且其强度大于铝材,可用于薄型框架制作。通过开展全尺寸钢幕墙POSN STEEL WALL的结构性能试验,并将试验结果应用于实际项目,分析其施工性能。

Effect of fiber angle on LYP steel shear walls behavior

Steel shear wall(SSW) was properly determined using numerical and experimental approaches.The properties of SSW and LYP(low yield point) steel shear wall(LSSW) were measured.It is revealed that LSSW exhibits higher properties compared to SSW in both elastic and inelastic zones.It is also concluded that the addition of CFRP(carbon fiber reinforced polymers) enhances the seismic parameters of LSSW(stiffness,energy absorption,shear capacity,over strength values).Also,stress values applied to boundary frames are lower due to post buckling forces.The effect of fiber angle was also studied and presented as a mathematical equation.

Seismic performance evaluation of steel frame-steel plate shear walls system based on the capacity spectrum method

This paper presents some methods that the standard acceleration design response spectra derived from the present China code for seismic design of buildings are transformed into the seismic demand spectra, and that the base shear force-roof displacement curve of structure is converted to the capacity spectrum of an equivalent single-degree-of-freedom （SDOF） system. The capacity spectrum method （CSM） is programmed by means of MATLABT.0 computer language. A dual lateral force resisting system of 10-story steel frame-steel plate shear walls （SPSW） is designed according to the corresponding China design codes. The base shear force-roof displacement curve of structure subjected to the monotonic increasing lateral inverse triangular load is obtained by applying the equivalent strip model to stimulate SPSW and by using the finite element analysis software SAP2000 to make Pushover analysis. The seismic performance of this dual system subjected to three different conditions, i.e. the 8-intensity frequently occurred earthquake, fortification earthquake and seldom occurred earthquake, is evaluated by CSM program. The excessive safety of steel frame-SPSW system designed according to the present China design codes is pointed out and a new design method is suggested.

Development of realistic design fire time-temperature ：urves for the testing of cold-formed steel wall systems

Fire resistance rating of light gauge steel frame （LSF） wall systems is obtained from fire tests based on the standard fire time-temperature curve. However, fire severity has increased in modem buildings due to higher fuel loads as a result of modern furniture and light weight constructions that make use of thermoplastics materials, synthetic foams and fabrics. Some of these materials are high in calorific values and increase both the spread of fire growth and heat release rate, thus increasing the fire severity beyond that of the standard fire curve. Further, the standard fire curve does not include a decay phase that is present in natural fires. Despite the increasing usage of LSF walls, their behavior in real building fires is not fully understood. This paper presents the details of a research study aimed at developing realistic design fire curves for use in the fire tests of LSF walls. It includes a review of the characteristics of building fires, previously developed fire time-temperature curves, computer models and available parametric equations. The paper highlights that real building fire time-temperature curves depend on the fuel load representing the combustible building contents, ventilation openings and thermal properties of wall lining materials, and provides suitable values of many required parameters including fuel loads in residential buildings. Finally, realistic design fire time-temperature curves simulating the fire conditions in modem residential buildings are proposed for the testing of LSF walls.

An effective simplified model of composite compression struts for partially-restrained steel frame with reinforced concrete infill walls

To resolve the issue regarding inaccurate prediction of the hysteretic behavior by micro-based numerical analysis for partially-restrained（PR）steel frames with solid reinforced concrete（RC）infill walls,an innovative simplified model of composite compression struts is proposed on the basis of experimental observation on the cracking distribution,load transferring mechanism,and failure modes of RC infill walls filled in PR steel frame.The proposed composite compression struts model for the solid RC infill walls is composed ofαinclined struts and main diagonal struts.Theαinclined struts are used to reflect the part of the lateral force resisted by shear connectors along the frame-wall interface,while the main diagonal struts are introduced to take into account the rest of the lateral force transferred along the diagonal direction due to the complicated interaction between the steel frame and RC infill walls.This study derives appropriate formulas for the effective widths of theαinclined strut and main diagonal strut,respectively.An example of PR steel frame with RC infill walls simulating simulated by the composite inclined compression struts model is illustrated.The maximum lateral strength and the hysteresis curve shape obtained from the proposed composite strut model are in good agreement with those from the test results,and the backbone curve of a PR steel frame with RC infill walls can be predicted precisely when the inter-story drift is within 1%.This simplified model can also predict the structural stiffness and the equivalent viscous damping ratio well when the inter-story drift ratio exceeds 0.5%.

Manufacture of Extra-Thin Wall Steel Pipe by LD Cluster Mill

The manufacture of extra-thin wall steel pipe by LD cluster mill through suitable tool design and process design was described in detail.The defects in steel pipe produced during rolling were analysed and some measures were taken to improve them.Five kinds of extra-thin wall steel pipes have been produced successfully,which are as follows:φ18.5mm×0.25 mm,φ15.5mm×0.25 mm,φ11.4mm×0.2mm,φ14- 24mm×0.12 mm,φ21.74mm×0.12 mm.

Improving behavior of semi-supported steel plate shear walls

In spite of the good performance of the steel plate shear wall(SPSW)in recent earthquakes and experimental studies,the need for huge columns to surround the infill plate is a major shortcoming of the system.This shortcoming can be resolved by using semi-supported SPSW.The semi-supported SPSW has secondary columns that prevent the transfer of stress from the infill plate to the main columns.In spite of extensive experimental and numerical investigations on SPSWs,there are many ambiguities regarding the behavior of the semi-supported SPSW.Although stress in the columns is reduced,incomplete diagonal tension field action is formed in the infill plate that creates new problems.In this paper,a new type of semi-supported SPSW is presented in which the steel plate and the secondary columns are angled.The creation of the angle of the plate and the secondary column makes it possible to use the full capacity of the steel plate as well as the capacity of the secondary columns.Numerical results showed that the wall with a 60°angle has a favorable performance relative to the semi-supported wall.Moreover,with the 60°angle,stiffness,strength and energy absorption is increased.The angle of the secondary columns has little effect on the non-elastic stiffness.Nevertheless,using a wall with an angle of more than 90°can neutralize the wall’s behavior relative to conventional walls.Therefore,the wall with a 60°angle as an optimal angle is recommended.

Microstructures and Properties of 550 MPa Grade High Strength Thin-walled H-beam Steel

The microstructures and mechanical properties of 550 MPa grade lightweight high strength thin-walled H-beam steel were experimentally studied. The experimental results show that the microstructure of the air-cooled H-beam steel sample is consisted of ferrite, pearlite and a small amount of granular bainites as well as fine and dispersive V（C,N） precipitates. The microstructure of the water-cooled steel sample is consisted of ferrite and bainite as well as a small amount of fine pearlites. The microstructure of the water-cooled sample is finer than that of the air-cooled sample with the average intercept size of the surface grains reaching to 3.5 gna. The finish rolling temperature of the thin-walled high strength H-beam steel is in the range of 750 ~C-850 ~C. The lower the finish rolling temperature and the faster the cooling rate, the finer the ferrite grains, the volume fraction of bainite is increased through water cooling process. Grain refinement strengthening and precipitation strengthening are used as major strengthening means to develop 550 MPa grade lightweight high strength thin- walled H-beam steel. Vanadium partially soluted in the matrix and contributes to the solution strengthening. The 550 MPa grade high-strength thin-walled H-beam steel could be developed by direct air cooling after hot rolling to fully meet the requirements of the target properties.

Research on seismic performance of shear walls with concrete filled steel tube columns and concealed steel trusses

In order to further improve the seismic performance of RC shear walls, a new composite shear wall with concrete filled steel tube （CFT） columns and concealed steel trusses is proposed. This new shear wall is a double composite shear wall; the first composite being the use of three different force systems, CFT, steel truss and shear wall, and the second the use of two different materials, steel and concrete. Three 1/5 scaled experimental specimens： a traditional RC shear wall, a shear wall with CFT columns, and a shear wall with CFT columns and concealed steel trusses, were tested under cyclic loading and the seismic performance indices of the shear walls were comparatively analyzed. Based on the data from these experiments, a thorough elastic-plastic finite element analysis and parametric analysis of the new shear walls were carried out using ABAQUS software. The finite element results of deformation, stress distribution, and the evolution of cracks in each phase were compared with the experimental results and showed good agreement. A mechanical model was also established for calculating the load-carrying capacity of the new composite shear walls. The results show that this new type of shear wall has improved seismic performance over the other two types of shear wails tested.

The Continuum Analytical Method of Steel Frame- Reinforced Concrete Shear Wall Mixed Structure

The inter-story drift stiffness considered the semirigidity of beam and column joints connection, and P-Delta second order effect of steel frame parts in the mixed structure is presented in the paper. After considering on the influence of semirigidity between steel beams and steel columns, second order effect of beam-column members for steel frame and structural second order effect, the traditional continuum analytial method used in RC shear-frames wall structure is developed to steel frames-reinforced concrete shear wall mixed structure subject to horizontal load in this paper. A continuum approach, which is suitable for analyzing steel frames-reinforced concrete shear wall mixed structure subject to horizontal load, is presented. The method is relatively simple and more practical. It will be referred to structural design for steel frames-reinforced concrete shear wall mixed structure.

Study on the Structural Performance of Steel Plate Shear Wall with Slits on Both Sides

This paper presents a new type of two sides slotted steel plate shear wall, and carries on the analysis to the finite element elastic buckling, respectively discusses the critical buckling load and the buckling mode. For the steel plate shear wall without stiffening ribs on both sides, the paper given the buckling coefficient formula, and give design proposal and reference value of steel plate shear wall with stiffened on both sides.

Static behavior of semi-rigid thin-walled steel-concrete composite beam-to-column joints with bolted partial-depth flush end plate:experimental study

A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints.

Experimental and analytical study on seismic behavior of steel-concrete multienergy dissipation composite shear walls

In this paper, a steel-concrete multi-energy dissipation composite shear wall, comprised of steel-reinforced concrete （SRC） columns, steel plate （SP） deep beams, a concrete wall and energy dissipation strips, is proposed. In order to study the multi-energy dissipation behavior and restorability after an earthquake, two stages of low cyclic loading tests were carded out on ten test specimens. In the first stage, test on five specimens with different number of SP deep beams was carried out, and the test lasted until the displacement drift reached 2%. In the second stage, thin SPs were welded to both sides of the five specimens tested in the first stage, and the same test was carried out on the repaired specimens （designated as new specimens）. The load-bearing capacity, stiffness, ductility, hysteretic behavior and failure characteristics were analyzed for both stages and the results are discussed herein. Extrapolating from these results, strength calculation models and formulas are proposed herein and simulations using ABAQUS carried out, they show good agreement with the test results. The study demonstrates that SRC columns, SP deep beams, concrete wall and energy dissipation strips cooperate well and play an important role in energy dissipation. In addition, this study shows that the shear wall has good recoverability after an earthquake, and that the welding of thin SP＇s to repair a deformed wall is a practicable technique.

Analysis and seismic tests of composite shear walls with CFST columns and steel plate deep beams

A composite shear wall concept based on concrete filled steel tube （CFST） columns and steel plate （SP） deep beams is proposed and examined in this study. The new wall is composed of three different energy dissipation elements： CFST columns; SP deep beams; and reinforced concrete （RC） strips. The RC strips are intended to allow the core structural elements - the CFST columns and SP deep beams - to work as a single structure to consume energy. Six specimens of different configurations were tested under cyclic loading. The resulting data are analyzed herein. In addition, numerical simulations of the stress and damage processes for each specimen were carried out, and simulations were completed for a range of location and span-height ratio variations for the SP beams. The simulations show good agreement with the test results. The core structure exhibits a ductile yielding mechanism characteristic of strong column-weak beam structures, hysteretic curves are plump and the composite shear wall exhibits several seismic defense lines. The deformation of the shear wall specimens with encased CFST column and SP deep beam design appears to be closer to that of entire shear walls. Establishing optimal design parameters for the configuration of SP deep beams is pivotal to the best seismic behavior of the wall. The new composite shear wall is therefore suitable for use in the seismic design of building structures.

Seismic responses of the steel-strip reinforced soil retaining wall with full-height rigid facing from shaking table test

To investigate the seismic response of the steel-strip reinforced soil retaining wall with fullheight rigid facing in terms of the acceleration in the backfill, dynamic earth pressure in the backfill, the displacements on the facing and the dynamic reinforcement strain distribution under different peak acceleration, a large 1-g shaking table test was performed on a reduced-scale reinforced-earth retaining wall model. It was observed that the acceleration response in non-strip region is greater than that in potential fracture region which is similar with the stability region under small earthquake,while the acceleration response in potential fracture region is greater than that in stability region in middle-upper of the wall under moderately strong earthquakes. The potential failure model of the rigid wall is rotating around the wall toe. It also was discovered that the Fourier spectra produced by the inputting white noises after seismic wave presents double peaks, rather than original single peak, and the frequency of the second peak trends to increase with increasing the PGA(peak ground amplitude) of the excitation which is greater than 0.4 g. Additionally,the non-liner distribution of strip strain along the strips was observed, and the distribution trend was not constant in different row. Soil pressure peak value in stability region is larger than that in potential fracture region. The wall was effective under 0.1 g-0.3 g seismic wave according to the analyses of the facing displacement and relative density. Also, it was discovered that the potential failure surface is corresponds to that in design code, but the area is larger. The results from the study can provide guidance for a more rational design of reinforced earth retaining walls with full-height rigid facing in the earthquake zone.

Evaluation of the Performance of Galvanized Steel Support in Construction of Living Wall Systems

Currently, Living Wall Systems (LWSs) are assuming great importance in the built environment, due to environmental and aesthetic advantages, as well as the use of urban residual space and underutilized surfaces of buildings. However, the maintenance and the durability of the materials used have been a challenge for architects and professionals in the field. The aim of this paper is to evaluate the anti-corrosion performance of a steel framing profile, galvanized carbon steel (55% Al-Zn), a sustainable material with easy assembly, to apply LWS in the hot and humid tropical climate of Niterói (Rio de Janeiro, Brazil). In order to create the conditions of the tests, “X” cut were made in Al-Zn coating, sanding, and application of epoxy and glass fiber-reinforced polyester. After the experiments that lasted four months, the 55% Al-Zn coating was analyzed using Scanning Electron Microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of the tests were promising for the use of this galvanized steel for application as a support for green vertical facades. 55% Al-Zn coatings are recommended for marine atmospheres due to their good anti-corrosion performance.

高烈度地区体育馆类公共建筑结构设计探讨

风雨操场作为体育馆类公共建筑,通常造型独特且体型复杂;而作为乙类建筑,存在大跨度、水平和竖向刚度分布不均等结构分析中较难处理的问题,因此其计算分析较为严格,而宁夏银川作为8度区,其抗震要求则更为严格且计算分析亦更为复杂。以银川一中风雨操场为例,对体育馆类结构中存在的问题及其处理方法进行了分析和探讨,为同类建筑的结构设计提供参考。

Effect of the Heat-treatment Temperature on the Mechanical Properties and Microstructural Evolution of Cold-rolled Twinning-induced Plasticity Steel

TWIP steels with 70% cold-rolled reduction were heated at 500, 600, 700, 800, 900, 1000, and 1100 ℃. Then, the properties before and after heating were examined through tensile and hardness experiments. The microstructures were also analyzed by optical microscopy and transmission electron microscopy. The relationship between the properties and microstructure was examined as well. Finally, the evolution process of cold-rolled microstructures during heating was discussed in detail. Moreover, some conclusions can be drawn, and the heating evolution characteristics are described.

Parametric analysis of steel plated shear structures

Due to outstanding ductility and high strength,the steel plate shear wall(SPSW)is recognized as a good lateral system for building structures; particularly as it interacts with earthquake resistant design.This study aims to reveal the dynamic and cyclic behavior of steel plated shear wall.Finite element method of analysis was implemented in order to simulate the behavior of such a wall structure.To determine the dynamic behavior of un-stiffened plate shear wall,two different analytical models were implemented.The post buckling strength of steel plate subjected to lateral loading was also employed.The story shear-drift diagrams of steel shear wall system were presented.The strength and ductility of the system obtained from the analysis were compared with those of steel shear wall tests reported before.The pertinent parameters of the steel shear wall system such as plate thickness,column and beam stiffness and the plate aspect ratio were recognized and their effects were recorded.The effect of stiffeners on the behavior of the SPSW was also investigated.

Seismic behavior and mechanism analysis of innovative precast shear wall involving vertical joints

To study the seismic performance and load-transferring mechanism of an innovative precast shear wall(IPSW) involving vertical joints, an experimental investigation and theoretical analysis were successively conducted on two test walls. The test results confirm the feasibility of the novel joints as well as the favorable seismic performance of the walls, even though certain optimization measures should be taken to improve the ductility. The load-transferring mechanism subsequently is theoretically investigated based on the experimental study. The theoretical results show the load-transferring route of the novel joints is concise and definite. During the elastic stage, the vertical shear stress in the connecting steel frame(CSF) distributes uniformly; and each high-strength bolt(HSB)primarily delivers vertical shear force. However, the stress in the CSF redistributes when the walls develop into the elastic-plastic stage. At the ultimate state, the vertical shear stress and horizontal normal stress in the CSF distribute linearly; and the HSBs at both ends of the CSF transfer the maximum shear forces.