地震作用下框架整体与局部损伤的相关性

根据框架结构耗散塑性变形能与存储弹性变形能能力的损失界定结构的整体损伤，根据塑性铰耗散塑性变形能能力的损失来界定局部损伤，并以拟力法为基础推导了局部损伤与整体损伤的解析表达式，进而讨论框架结构局部损伤与整体损伤的相关性。研究表明，控制框架结构整体损伤的手段有：减小局部损伤区域的强度衰减、提高局部损伤区域的极限转动能力和减小局部损伤区域的残余变形。其机理是通过提高局部损伤区域的耗能能力与约束能力来提高整个结构耗散与存储地震能量的能力；框架结构整体损伤与局部损伤的加权值较为接近，可以采用框架局部损伤的加权值来近似估计结构的整体损伤值。     

The Hysteretic Performance Analysis and Experiment on K-type Overlap Joints of Circular Steel-tubes

Joints are the most important parts of the space structure, the load-derormation curve (hysteretic curve) under repeated loading is the comprehensive reflection of their mechanical properties such as ductility, energy dissipation capacity, strength, stiffness and so on. By the simulation experiment analysis and the finite element simulation between the two models of hidden welding and no-welding hidden in K-type node in the chord axial reciprocating load resulted in the failure modes and hysteretic curve, the result of comparative analysis about finite elements is consistent with that of experiment study. The results show that the destroyment at hidden welding seam node is partly, the take-over is broken down at the welds finally. The welding line is destroyed overall when facing the destroyment of no-welding node. The carrying capacity of the hidden welding is obvious. Through the finite element simulation analysis instead of phase through node hysteretic performance test is feasible.     

X形配筋增强高强钢筋异形柱边节点抗震性能试验研究

通过对核心区应用X形配筋增强的高强钢筋异形柱边节点和同等条件下未被增强的高强钢筋异形柱边节点进行拟静力试验研究，对比分析异形柱边节点的破坏特征、滞回曲线、承载能力、位移及延性、刚度退化、耗能能力等抗震性能指标。研究结果表明，配置HRB500高强钢筋异形柱边节点比配置600 MPa级的边节点承载能低，但滞回性能好，变形能力强，刚度退化推迟，耗能能力强；在核心区加入X形配筋，均可以改善高强钢筋异形柱边节点的破坏特征，使边节点抗剪能力、变形能力、耗能能力增强，刚度退化推迟，提高异形柱边节点抗震性能，配置HRB500高强钢筋的试件核心区应用X形配筋加强后抗震性能提高效果更好。     

Performance of New-type Steel Tube Buckling-Restrained Brace with Reinforced Concrete Outside

A New-type Steel Tube Buckling-Restrained Brace with Reinforced Concrete outside (ST-BRB-RC) was introduced in this paper. Six specimens of the ST-BRB-RC were designed and cyclic loading test were carried out to study the hysteretic energy dissipation performance of the six specimens. And then, ABAQUS finite element analysis was used to study the performance of four specimens. The results indicated that the ST-BRB-RC had stable and full hysteretic curve. The bearing capacity of the ST-BRB-RC was stable and the hysteretic behavior was excellent. And the analysis model of ST-BRB-RC could be described by a bilinear model. The construction of the ST-BRB-RC was reasonable, and the energy dissipation mechanism of the ST-BRB-RC was clear. It is proved that the design philosophy of using reinforced concrete for exterior restrained element was available.     

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.     

Static Behavior of Rigid Connections of H-beams with Corrugated Webs

Steel H-beams with corrugated webs can provide high shear-buckling resistance with very thin webs, which results in saving of steel. Common beam-to-column rigid connections are not suitable for H-beams with corrugated webs, so 2 types of rigid connections are proposed .In this paper,2 static tests of beam-to-column rigid connections of H-beams with corrugated webs were conducted. And the test results were compared with the results from finite element analysis and the results calculated from the practical design formulas to verify the validity of the results from ABAQUS FEA and reliability from the practical design formulas. Parametric studies were carried out to investigate the bearing capacity of the pinned connection with variations in the thickness of the endplate, the connecting plate and the corrugation at the breaking point.     

结构消(耗)能元件芯材SN490B本构关系数值模拟

采用消(耗)能元件的结构在遭受地震作用时,元件芯材首先屈服进入塑性阶段,利用其滞回变形消耗地震输入能量,保护主体结构,元件芯材本构关系的数值模拟是对采用消(耗)能元件结构进行抗震分析与设计的基础。为更真实地模拟结构消(耗)能元件芯材在单调和循环荷载下的本构响应,更准确地对采用消(耗)能元件结构进行结构弹塑性地震响应分析,对常用作消(耗)能元件芯材的日本高延性钢材SN490B的单调、循环加载本构及循环骨架曲线进行了数值模拟,包括：采用Esmaeily-Xiao二次流塑性模型模拟材料在单调荷载作用下弹性段、屈服段、强化段和二次流塑段4个阶段;采用混合强化模型模拟材料循环荷载作用下的本构响应,运用大型通用有限元软件ABAQUS结合数值模拟参数对16种不同循环加载制度下的循环加载试验进行模拟,并与试验结果进行对比;采用Ramberg-Osgood模型、无量纲化的Ramberg-Osgood模型及两段式模型模拟循环骨架曲线。研究结果表明：所采用数学模型可以较好地模拟SN490B钢材单调、循环加载本构响应及循环骨架曲线,数值模拟与试验结果拟合较好。     

Maximum Displacement Estimation of Seismic Structures Based on Hysteresis Energy

Based on characteristics of hysteretic energy of structures which are simplified single freedom degree systems and under the short duration impulse modle mid duration and long duration modle earthquakes, correlation between the maximum hysteretic energy increment per cycle and the maximum inelastic displacement of different structures is investigated. Simplified equations to estimate the maximum inelastic displacement are obtained. The validity of the equation is recognized. It is pointed out that the impact destroy of the structures may occur when energy increment per cycleis 50 80 percent of total hysteretic energy, and the maximum hysteretic energy increment per cycle, and that the maximum inelastic displacement can be used to evaluate aseismic capacity.If energy increment per cycleis small relative to total hysteretic energy, the destroy of the structures by cumulate dissipation energy may occur, and the total hysteretic energy can be used to evaluate aseismic capacity.     

Analysis of Hysteretic Performance of C-section Specimens of Cold-formed Steel

Seven specimens were loaded with axial force and horizontal cycle force to analyze the hysteretic performance and the influencing factor as well. The influence of axial compression ratio and aspect ratio on the hysteretic performance was investigated, including the buckling behaviors and the energy dissipation. And the positive role of combined effects on the hysteretic performance of cold-formed specimens was studied emphatically. The experiment reveals that a large axial compression ratio incurs a serious decrease on hysteretic performance, while the combined effects give an increase on it. In addition, the numerical mode is set up. Considering double nonlinearity, the results of experiment and simulation match each other well. Based on the data, it is obtained that local buckling plays a great negative role during the loading course. At last, the characteristics of hysteretic performance of cold-formed steel specimens are concluded and some suggestions are given.     

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.     

Hysteretic Behavior of Composite Deep Beam Infilled Steel Frame

The Quasi static tests of one steel frame and two the composite deep beams infilled steel frames were carried out. The effects of the deep beams on the load capacity, ductility, hysteretic property and energy dissipation of pure steel structure were analyzed. It is found that the hysteresis curve is a straight line with the constant of the stiffness at the beginning and without residual deformation. And the hysteresis curve of specimen was full after yielding, and the skeleton curves had a clear plastic flow phase with triple linear. The lateral drifts of the beam specimens at failure were 1/25 and 1/22. The composite deep beams enhance the initial stiffness, yield load and maximum load bearing capacity of steel frame. Therefore, seismic performance of the composite deep beams is better.     

Experimental Analysis on Seismic Performance of Steel Bracing Bound-Column Component

The seismic resistant performance and failure mechanism of the steel bracing Bound-Column were analyzed with tests and the finite element method. Two-story steel bracing Bound-Column test specimen was selected. The braces adopt long leg back-back double angle. Tests were divided into three groups, including one monotonic loading test and two cyclic tests. Lateral load-bearing capacity, stiffness and hysteretic behavior of the steel bracing Bound-Column were obtained by the comparison of test results and the finite element method. Results show that the steel brace of Bound-Column contributes a lot to its load capacity and stiffness, while the external frame provides little lateral rigidity and capacity. Bound-Column failure occurs only in the steel braces, while the external frame is with no damage.     

单层柱面网壳抗连续倒塌性能

研究了不同荷载布置形式、支承方式条件下,单层柱面网壳的抗连续倒塌性能和倒塌破坏模式,采用基于构件承载能力的敏感性评价指标,分析了初始缺陷、压杆失稳等因素对杆件、节点敏感性指标的影响。结果表明,当采用四边支承时,满跨均布荷载起控制作用,跨中节点为敏感构件,与之相邻斜杆为关键构件;当采用纵向两边支承时,半跨均布荷载起控制作用,杆件和节点的敏感性指标在1/3跨处最大,支座处最小。当考虑初始缺陷时,杆件、节点重要性系数分别增大了41%和53%;当考虑压杆失稳时,杆件和节点重要性系数分别增大了45%和62%。通过对关键构件进行加强,可以优化该类结构的抗连续倒塌性能。     

EXPERIMNTAL RESEARCH ON THE CRACK RESISTANCE AND BEARING CAPACITY OF PRESTRESSED BRICK MASONRY WALLS UNDER CYCLIC LOADING

By comparing the tests of prestressed and nonprestressed brick masonry walls with peripheral beams and Constructional columns, under cyclic lateral loading,the apperaence and development of Cracks,failure mechanism,hysteretic behavior,strength,stiffness,ductility and ener-gy dissipation of the brick rnasonry walls arc studied.Only the crack resistance and bearing capacity of walls are discussed in this paper.It is shown that prestressing on brick masonry wall can obviotisly improve its seismic behavior.Morcover,calculating methods for the crack resistance and the ultimate bearing capacity are presented,and the caculating results are identical with the tests.     

Experimental Analysis of Bearing Capacity of Triangle Hollow Flange Beam

On the basis of Hollow Flange Beam (HFB) which is proposed by Australian researchers, a new pattern triangle hollow flange beam (THFB) is presented. According to the experimental test and finite element simulation, the failure processes of THFB and traditional I-beam under concentrated load are compared, and then the obvious differences between the failure modes of these two type beams are founded. The local buckling is easily occurred for the THFB, while overall instability is easily occurred for traditional I-beam, and THFB possesses have better bending performance and twist resistance than those of traditional I-beam. with the experiments, finite element analysis is carried out by FE software ANSYS, and the FE results agree with the test results. Based on FE models, the parameter analysis is carried out for THFB. The parameters mainly include the thickness of top flange, the width of top flange, the thickness of web and the yield strength of steel. The change rule of the bearing capacity of THFB with different parameters can be achieved by parameter analysis. Finally, based on the above results, the applicability of the calculation formula of Eurocode3 to compute the bearing capacity of THFB is discussed. The results show that it is safe and reliable to adopt the calculation formula of Eurocode3 to compute the bearing capacity of THFB, Whilst the estimation is relatively conservative.     

Experimental Study on Seismic Behavior of Penetrated Interior Diaphragm on One Side Beam-to-Column Connection for Concrete-Filled Square Steel Tube

A total of three experimental specimens of penetrated interior diaphragm on one side had been tested under low-cyclic reversed loading to study the hysteric behavior,strength and stiffness degradation,ductility,energy dissipation capacity and the failure modes.The only difference of all specimens was the axial compression ratio.Experimental results show that the story drift ductility ratios are 2.11~2.32,and the energy dissipation ratios are 1.141~1.502 at the peak load.Additional anti-seismic design and research recommendations are presented.     

配置600 MPa级高强钢筋T形柱抗震性能试验研究

600 MPa级钢筋是一种新型高强度钢筋，为研究该钢筋应用于异形柱结构体系的可行性，对7根不同轴压比、体积配箍率和钢筋强度的混凝土T形柱试件进行低周往复荷载试验，分别对其承载力、位移、滞回曲线、骨架曲线、刚度退化和耗能性能进行研究，综合评估其抗震性能。研究结果表明：配置600 MPa级钢筋的混凝土T形柱具有良好的变形能力和承载能力，提高配箍率能有效提高试件的抗震性能，提高轴压比可以提高试件的承载力，但降低其变形能力。随着钢筋强度的提高，试件的承载力显著提高。     

Experiment research on aseismatic capability of diagonally crossing reinforced coupling beams with the small ratio of span to depth fire safety design for ancient buildings

Low frequency cyclic loading experiments are carried out with six diagonally crossing reinforced coupling beams. The ratio of the span to depth is 1.0,1.5,2.0 and 2.5. The paper analyzes the behavior of crack development, failure mode, ductility, stiffness degeneration, hysteretic and energy dissipation of these specimens. The results show that the aseismatic behavior of properly reinforced diagonally cross reinforced coupling beams is better than conventionally reinforced coupling beams, and this kind coupling beam can get no less than 3.5 chord rotation ductility at the 0.20 ratio condition of shear to compression. For diagonally crossing reinforced coupling beams with the small ratio of span to depth, the mechanism of the main force transfer system is the main diagonal strut tie model and stirrup truss model     

Experimental Research of Vertically-Loaded RC Joint of Local Transfer from Inclined Column with Different Angle to Beeline-Shaped Short Shear Wall

According to test results of two different angle specimens of local transfer RC joint from inclined column to Beeline-shaped short shear wall under vertical static loads and results of corresponding finite element analysis(ANSYS), fundamental behaviors of the joint are achieved for the change of the angle.The result indicates that there is much difference in the stress distributions of the transfer beam and short shear wall for different angles of inclined column, which shows that the larger angle, the more great tensile force and the earlier crack in the transfer beam and the lower capacity. Otherwise, the angle is smaller, the evener stress distributions in short shear wall, the later crack, the worse degenerate in the transfer beam and the higher capacity.Furthermore, the mechanical behaviors of the joint obviously followed the characteristics of a truss model.