Method for measuring shear stress-strain relationship of thin adhesive layer

This paper uses the combined bonding disc specimen, with a round end surfaces at both ends of the longitudinal adhesive joint and chamfered steel substrates hither, forms a shear stress distribution of uniform coefficient more than 0.97 and controls the normal tension stress along the bonding surfaces to a very low level. By means of the built-in high accuracy displacement measuring system of uniaxial INSTRON servo equipment, it eliminates the measuring system deformation from the measured total deformation, and then obtains the shear deformation of the joint, and eventually converts into the shear strain of the adhesive joint. The results of experiments using adhesive samples show that the bonding disc specimens are characterized by shear failure of the adhesive joint layers, so it can be thought that the method of combined bonding disc specimens can reveal the right shear properties of adhesives. The measured shear strength can be used as material strength criterion and the measured shear stress-strain relationship can be used in the load capacity analysis of bonded structural members. Because of the simplicity, the combined bonding disc specimen test method is suitable to be adopted in laboratories having displacement-controlled servo systems.     

Phase Transformation Diffusion Bonding of Titanium Alloy to Stainless Steel

Jointing of titanium alloy and stainless steel is very often in the fields like aviation, chemical plants etc. The combination of materials has the advantages of both titanium alloy and stainless steel and will reduce the consumption of titanium resource. The phase transformation diffusion bonding of TA17 titanium alloy to 0CriSNigTi stainless steel are carried out on Gleeble - 1500D. The effcet of maximum thermal cycle temperature, the tensile strength, the fracture surface and microstruture of the joints are investigated. The results show that TiFe and TiFe2 intermetallics and some solid solutions are formed along the interface, when maximum thermal cycle temperature increase, the area proportion of intermetallics in the fracture surface increase, which are detrimental to the mechanical properties of the transition joints.     

FEM Dynamical Analysis of the Reinforced Concrete Beam with Bonding Steel Plate

In order to researchmechanical capability of the reinforced concrete beam with bonding steel plate, adopting separatemethod to establish finite element model of the reinforced concrete beam with bonding steel plate, using FEM to study dynamical characteristics of the model, have got good results which can not be easily got using traditional resolution method, which can give referenceto study dynamical characteristics of the reinforced concrete beam with bonding steel plate.     

Mechanical Model of Steel Plate Composite Shear Walls

Based on concepts of mechanics, a mechanical model of novel type of steel plate composite shear wall is presented. The novel type of structure is formed by steel plate shear wall and T-shaped solid-web composite columns. Flexural stiffness of steel beams, lateral stiffness of the T-shaped solid-web composite columns, shear stiffness of steel plate composite shear wall and shear stiffness of beam-column connection are taken into account in the mechanical model. And the equivalent damping between steel plate and boundary is considered. Based on the deformation features of structures and the calculation hypothesis, the lateral stiffness model and the energy dissipation model of structures are developed. Meanwhile, the calculation equations of elastic ultimate and plastic ultimate of shear strength of structures are set up. The theoretical analysis results inosculate better with the results of experiment. The comparison between the result calculated from the formula and the experimental result shows that the calculation precision is high enough to meet the demand of theoretical analysis. The difference, including equivalent model, stress states, manufacturing defect and installation error, between the formula and the experiment has been further discussed.     

Interface Characteristic of Diffusion Bonding on Be/Cu/HR-1 Stainless Steel

Cu is used as the mesosphere material in the experiment, and the diffusion-bonding experiment of Be/Cu/HR-1 stainless steel is made on the Greeble1500 hot stimulation test-machine. The interface characteristics of the diffusion bonding are studied by means of the Scanning Electron-Microscope, the X-ray Diffraction and the HV-1000 Micro-hardness Tester. The results show that Cu can countercheck the mutual diffusion between Be and Fe, as well as the diffusion of Ni and Cr from the stainless steel to Be, resultingly, restrain the formation of the intermetallic compounds among them, but the Be_(2)Cu is formed because of diffusion of Cu, and the intermetallic compounds is firstly formed along grain boundry and distributed as net-like, and the diffusion of elements is made along the grain boundry and their diffusion is non-uniform, and also does not form the layer of the single intermetallic compound. The fracture of the sample lies at the Be/Cu interface area.     

Experimental Investigation of Steel Frames with Infill Prefabricated Reinforce-Concrete Shear Walls

In order to improve seismic performance of steel frame with prefabricated reinforce-concrete infill shear walls (SFCW), the ear bar device was used in the connection between the steel frame and the infill wall. Two one-bay, two story and one-third scaled models of SFCW were tested with low cyclic load. The working performance of ear bar connection, the cracks development in infill walls and deformation performance of SFCW were investigated. And the failure mode, hysteretic behavior,stiffness degradation,deformation and ductility and energy dissipation of composite structure were analyzed. The comparison study of steel frame with prefabricated, cast-in-place and silt reinforce-concrete infill shear walls was carried out. The results show that no failure occurs in the connection between the steel frame and the infill wall because ear plates below and up the beam-to-column connections are added in the specimens, and the connection device of ear plate presents good working performance. The properly designed SFCW has good ductility.     

A New Method of Separating the Shear Waves Splitting in Anisotropic Media

For azimuthal anisotropy seismic exploration, it is very important to separate the fast and slow shear waves splitting in this type of anisotropic media. Many researchers have worked on this problem, but their methods are not realistic in exploration. In this paper, a new method of separating the shear waves splitting in EDA media is presented, that can be directly applied to actual use. Through numerical examples, it can be found that the method is highly efficient and accurate.     

Simplified Elasto Plastic Analytical Model for Stiffened Steel Plate Shear Wall with Slits

Based on the mechanism of steel slit wall, a simplified elasto plastic analytical model which allows for nonlinear dynamic and static analysis was proposed. The parameters of simplified model related to configuration and nonlinear behavior were defined. In order to validate the simplified model, the pushover analysis of steel slit wall and a frame with steel slit wall were conducted. The results show that the load displacement curves obtained from simplified models, experiments and FEM are similar. The proposed model can fully represent the mechanism of steel slit wall, and it can correctly predict the internal forces and deformations of each member in the model.     

Finite Element Analysis of Hysteretic Behavior of PR Steel Frame-steel Plate Shear Wall

In order to investigate the seismic behavior of partially-restrained steel plate shear wall (Steel Plate Shear Wall, SPSW), the effects of partially-restrained connection on the hysteretic behavior, lateral bearing capacity, stiffness, energy dissipation of SPSW with strong and weak steel frame were simulated under low cyclic loading via equivalent strip model that had been verified by experiment. The results show that hysteretic behavior of SPSW has dual characters. The hysteretic curves of SPSW with strong surrounding steel frame become fat, and the hysteretic curves of SPSW with weak surrounding steel frame become narrow. With the increase of the bending capacity of PR connection, the hysteretic curves of SPSW become fat gradually, and the capacity of energy dissipation and lateral bearing increase. However, the effect on lateral stiffness of PR connection of SPSW with strong steel frame is higher than the one with weak steel frame.     

Horizontal Ultimate Bearing Capacity Analysis of Multi-story Multi-span Steel Plate Shear Wails system

The effectiveness of equivalent strip model calculating the horizontal ultimate bearing capacity of multi-story steel plate shear walls(SPSW)by using the software SAP2000 to make Pushover analysis was demonstrated by comparing the simulated values with results from experimental studies performed by different researchers.The effect of different slenderness ratios on the ultimate bearing capacity of four-story single-span SPSW and four-story three-span dual steel shear walls system subjected to the inverse triangular load was obtained by the verified analytical model,which was compared with the performance of corresponding bare frames.The slenderness ratio of 250~300 is suggested for the design of SPSW.     

Experimental Analysis on Energy Dissipation Mechanism and Seismic Performance of Steel Truss Coupling Beam-Coupled Shear Wall Structure

Pseudo-dynamic tests and low cyclic reversed loading tests on two-floor coupled shear wall planar structures were conducted, and one is arranged with two steel truss coupling beams, the other is arranged with a steel coupling beam and a RC coupling beam. The shear walls’ seismic response under different earthquake intensity was deliberated, Their failure mechanism, bearing capacity, hysteretic ductility, energy dissipation mechanism, and stiffness and strength degradation mechanism were analyzed as well. The results show that the shear wall with two steel truss coupling beams has reasonable stiffness distribution. Its energy dissipation mechanism, stiffness and strength degradation mechanism can fulfill the demands of coupled shear wall’s seismic design: under rare earthquake, it can maintain good bearing capacity and stiffness, and keep restraining the walls. Its seismic performance is superior to RC coupling beams-coupled shear wall system.     

Experiment Research of Adhesive and Shearing Strength between the Concrete Member Poured with Special-shaped Steel Form and the Cement Mortar on its Surface

This paper systematically presents the experiment about the adhesive and shearing strengthbetween the concrete member poured with two kinds of steel form and the cement mortar on the membersurface. By the comparison of three groups of experiments, this paper draws a conlusion tha the adhesive and shearing strentgh between concrete member and cement mortar could be considerably increased if the special-shaped steel form was applied.     

Microstructure and Properties of the Dacromet Coating for 20 Steel

The Dacromet technology,which is a potential surface treatment method,has achieved extensive application in automobile industry.The Dacromet coating is prepared through dipping & curing process,and the microstructure and anticorrosion performance of zinc,aluminum galvanized specimens are comparatively investigated.The results shows that the zinc,aluminum,chromium distributed evenly and Zn/Al flakes overlapped and embedded in amorphous chromium binder in Dacromet coating which anticorrosion is superior to hot dip galvanized but slightly inferior to hot dip aluminum coating with lowered adhesion,its adhesive ability to matrix is weaker than that of aluminum coating.     

Numerical Method for Load Bearing Capacity of High Strength Steel Columns at Elevated Temperature

In order to make fire resistance design of high strength steel columns in building structures, the numerical calculation method on load bearing capacity of high strength steel columns at elevated temperature was investigated. By taking the mechanical property of high strength steel at elevated temperature into consideration, extension was made on the inverse calculation segment length method and the program to compute the load bearing capacity of high strength steel columns at elevated temperature was performed. The program was adopted to compute the load bearing capacity. The results obtained by the program and the finite element analysis were compared and good agreement had been found. The influence of magnitude, distribution mode of residual stress and initial geometry imperfection on ultimate load bearing capacity was analyzed by employing the program. It is shown that the extended method can be is shown used to calculate the load bearing capacity of high strength steel columns at elevated temperature; the magnitude and distribution mode of residual stress had little influence but the geometry imperfection have significant influence on ultimate load bearing capacity.     

基于模糊数学法的新建绿地土壤物理性能评价

城市绿地土壤的物理性能影响着城市生态系统的运行,为了研究城市绿地建设过程中不同层次土壤的物理性能,以西安植物园新区为典型案例,选取容重、总孔隙度、毛管孔隙度、非毛管孔隙度、田间持水量、自然含水量等六个指标,结合模糊数学法以及SPSS19.0与Excel软件对各层土壤的物理性能(Q)进行评价。结果显示,西安植物园新区表层土壤(0-25cm)、浅层土壤(25-50cm)、中层土壤(50-70 cm)、深层土壤(70-90cm)的Q值分别为21.69、61.24、71.19、66.89;分别处于极差水平、较差水平、良好水平、较差水平。平均Q值为55.25,处于较差水平。表层土壤与浅层土壤Q值过低的原因在于重型机械的重复碾压,碾压力对中层土的影响较小。随着土层深度的增加,深层土壤的Q值相对中层有所下降。各影响因子的权重比较显示,土壤容重是影响各层土壤物理性能优劣的重要因素,但随着土层的加深,土壤容重的权重逐渐降低。自然含水量的权重随着土层的加呈现逐步上升的趋势。     

不同阻燃剂对速生杨木胶合板性能的影响

选用自配阻燃剂和FRW阻燃剂处理杨木单板,探讨不同种类阻燃剂、浸渍时间、浸渍浓度、热压温度对胶合板载药量、胶合强度以及阻燃性能的影响。结果表明：选用自配阻燃剂时,载药量1.4322%~13.4726%,氧指数36.6%~89.9%,胶合强度0.131~0.798 MPa;选用FRW阻燃剂时,杨木阻燃胶合板的载药量1.5449%~14.7724%,氧指数45.3%~70.5%,胶合强度0.233~0.698 MPa。经过自配和FRW阻燃剂处理后,杨木胶合板的阻燃性能均得到明显改善,其中氧指数远大于日本JISD1322-77 中的难燃一级品的要求,但是其胶合性能显著下降。     

Nonlinear Analysis Technique of Refined Plastic-hinge Method for Steel Frame Structures

The refined plastic-hinge method is one of the simplified advanced analysis methods. The second order effects of the whole structure and its members, geometric imperfections and residual stress as well as the feature of semi-rigid connections can be taken into account in this method. The refined plastic-hinge method can be used in advanced analysis and design of planar steel frames, while its use in the advanced analysis of space frames needs to be developed. The technique associated with the dealing of different inelastic factors in advanced analysis of both the planar and space steel frames with practical refined plastic-hinge method and the available way to extend planar frame analysis to space frame analysis are reviewed in detail. The problems of the refined plastic-hinge method for advanced analysis are discussed in this paper.     

AM真菌接种剂与栽培基质对牡丹容器苗丛枝菌根侵染的影响

为了探索AM真菌（AMF）在牡丹种苗生产和观赏栽培中的合理应用,更好地利用其优势AM真菌菌种资源,培育优质牡丹菌根化容器苗,笔者以牡丹（Paeonia suffruticosa）容器苗为接种对象,设计筛选AM真菌接种剂、接种期和栽培基质最佳组合。结果表明：AM真菌接种剂对牡丹丛枝菌根形成均有显著影响,以Glomus geosporum（Gg）和Glomus mosseae（Gm）混合接种剂在第3剂量水平下效果最显著;随着株龄增大,丛枝菌根侵染效果显著降低,当年生苗侵染率、侵染强度、丛枝着生率、侵入位点数与菌丝长度均最高,分别为94.64%、13.2、51.8%、6.3个/mm根长、9.58 m/g干土,均显著地高于1年生苗、2年生苗和3年生苗;在备选的4种栽培基质中,以泥炭:珍珠岩:河沙（1:1:1）基质最合适,在接种后112天时侵染率、侵染强度、菌丝长度最高,分别为90.20%、22.50和2.2 m/g干土,均显著（P＜0.05）大于其他基质。因此,以当年生牡丹容器苗接种Gg+Gm,以及采用泥炭:珍珠岩:河沙（1:1:1）栽培基质最佳。     

Shear Deformation Properties of Sliding Zone Soil and Its Effect on Sliding Mechanism of a Landslide in the Three Gorges Reservoir Area

The mechanical properties of slip soil play a key role in landslide stability. In order to study this control mechanism, multigroup experiments on the slip soil of a landslide were conducted in the Three Gorges reservoir in Zigui county involving consolidated quick direct shear test and consolidated drained direct shear test, through which the strain hardening property of this slip soil has been studiedas well as mechanism of landslide deformation resulting from the strain hardening slip soil. The results show that from plastic deformation to shear failure, the shear stress applied to this slip soil increases all the way. After repeated shearing, its shear strength increases, and the greater the normal stress, the more the shear strength increases, in which process the angle of internal friction contributes the most to its shear strength variation. Through the field investigation and numerical modeling, how the strain hardening slip soil affects the landslide stability was studied. In the process of sliding, the frictional strength of the strain hardening slip soil increases after being shearing, leading to the consumption of the landslide’s kinetic energy, following the phenomenon that a temporary steady state occurs after a short distance sliding.