Nonlinear behavior of composite shear walls with vertical steel encased profiles

Research on seismic engineering of buildings using composite steel-concrete structural systems has increased in the past decade. One horizontal resisting system for buildings, placed in seismic areas, is the composite steel-concrete structural shear wall with steel encased profiles (CSRCW). The benefits of this structural system, relative to more common systems, include the performance characteristics when subjected to service or ultimate loads. The present paper summarizes the experimental results of recent research made on six experimental steel-concrete composite elements 1:3 scale, tested in laboratory under cyclic lateral loads. The experimental elements differ by the arrangement of the steel shapes embedded in the cross section of the wall and by the cross section type of the steel encased profiles. All specimens were tested under constant vertical load and cyclically increasing horizontal (lateral) loads. The tests were performed until failure. Using the recorded data during the tests, the following parameters are presented and discussed: maximum load capacity, stress and strain distribution in structural components (reinforcements, structural steel and on concrete surface), interstory drifts, cracking patterns, deformation and degradation capacity.     

Seismic performance of corrugated steel plate concrete composite shear walls

In this paper, composite shear walls with different encased steel plates (flat, horizontal corrugated, and vertical corrugated) were tested and simulated by Abaqus to investigate the seismic behavior of corrugated steel plate concrete composite shear walls (SPCSWs). The failure characteristics, deformation and energy dissipation capacity, and stiffness and bearing capacity of the structures under low‐frequency cyclic load were analyzed, and indexes of the seismic performance were obtained. The formulas of the shear‐bearing capacity of steel plate concrete composite shear walls are suggested, and the shear‐sharing ratio of each member is obtained. According to the obtained results, corrugated steel plates can bond with concrete well, and the bearing capacity of the vertical corrugated SPCSW are higher than that of the horizontal corrugated SPCSW. Compared with flat SPCSW, corrugated SPCSW has higher initial stiffness and lateral stiffness, better ductility and energy dissipation ability, and the degradation of bearing capacity and stiffness is slower. The shear‐sharing ratio of a steel plate is larger than that of reinforced concrete in the flat SPCSW and the vertical corrugated SPCSW, the shear force shared by steel plate and reinforced concrete in horizontal corrugated SPCSW is basically the same.     

半组合结构压弯构件滞回试验的有限元模拟

基于按结构材料力学功能建立离散化单元的思想,将混凝土离散为各向的弹塑性弹簧单元,建立了半组合结构柱的有限元模型。通过有限元软件ANSYS对6个半组合结构压弯构件进行了反复荷载作用下的滞回性能非线性分析,得到了其荷载一位移曲线,并与试验结果进行了对比。结果表明：由有限元模型得到的滞回曲线与试验曲线相似,模拟效果良好;该有限元模型能模拟构件的弹塑性行为和抗震性能,建模简单,结果可信,计算效率高,可用于构件滞回性能的参数分析。     

Theoretical and experimental study on composite steel-concrete shear walls with vertical steel encased profiles

The present work describes the theoretical study and the experimental tests on composite steel-concrete shear walls with steel encased profiles (CSRCW), performed at Politehnica University of Timi?oara, Romania. The composite steel-concrete structural shear walls with steel encased profiles can be used as horizontal resisting systems for buildings that require considerable large horizontal load capacity. The study consists in numerical analysis and tests on 1:3 scale experimental steel-concrete composite elements. The experimental elements differ by the arrangement of the steel shapes embedded in the cross section of the wall and by the cross section type of the steel encased element. Headed steel studs are provided to ensure the connection between the steel profiles and the concrete. The aim of this study is to analyze the nonlinear behavior of elements, focused on the connection between the steel profiles and the concrete respectively, to compare the behavior of shear walls with different steel shape encased profiles with typical reinforced concrete shear walls. Using the tests performed until failure, the maximum load, the deformation capacity and the dissipated energy were evaluated.     

Experimental and numerical study on eccentric compression performance of partially encased composite columns with corrugated web

Partially encased composite (PEC) members are becoming increasingly popular because of their high strength and suitability for prefabrication and assembly. Corrugated steel plate has higher out-of-plane stiffness than flat steel plate. When it is combined with concrete, the bonding between corrugated steel plate and concrete is more obvious than that between flat steel plate and concrete. For this reason, a new type of corrugated web PEC column (CPEC column) was proposed in this paper, and its eccentric compression performance was studied by experiment and numerical method. Nine specimens were tested, of which two were subjected to axial compression and seven were subjected to eccentric compression. The key factors considered in the experiment were the loading direction, load eccentricity, link spacing, and width-to-thickness ratio of flange. A three-dimensional finite element model of the CPEC columns was established and verified, and the influence of the wave angle of corrugated web on the behavior of CPEC columns under eccentric compression was investigated using a parametric study. Finally, the current design codes for estimating the interaction curve and bearing capacity of CPEC columns were assessed.     

带PEC柱的钢板剪力墙结构抗震性能试验研究

为了解决薄钢板剪力墙结构中框架柱易发生破坏而失效的问题,将强度高、刚度大的PEC柱引入薄钢板剪力墙结构,作为竖向边缘构件形成PEC-SPSW结构,分别对1榀带H形钢柱、2榀带PEC柱的钢板剪力墙结构,进行了低周往复荷载作用下的抗震性能试验研究。通过分析该结构的承载力、初始刚度、耗能能力、应力分布及破坏模式,得到了带PEC柱的钢板剪力墙结构具有更好的抗侧刚度、承载力和耗能性能。PEC柱构件对薄钢板有更好的锚固约束作用,从而使得薄钢板充分发挥屈曲后强度作用,带PEC柱的钢板剪力墙结构有更好的发展前景。     

焊接H型PEC组合短柱轴心受压试验研究

为了研究这种新型组合柱的受力性能,对9个焊接普通H型钢部分包裹混凝土组合短柱进行了轴压试验,试验主要考虑含钢率、翼缘宽厚比、横向系杆间距等对柱子的极限承载力的影响。通过分析得出,在不同含钢率下,影响PEC短柱承载力的因素。同时含钢率大小直接影响柱极限承载能力。     

方管钢筋混凝土柱的抗震性能和强度研究

钢管钢筋混凝土(STRC)柱是一种由薄壁钢管构成横向约束作用的普通钢筋混凝土柱。对23个方管混凝土短柱进行了循环或者单向轴压试验,并提出计算该类柱轴向承载强度的公式。此外,还对5个梁柱组合结构进行了轴向压力和水平循环荷载作用下的试验分析。试验结果表明,与普通钢筋混凝土柱相比,方形钢管柱具有更高的挠屈强度、位移延性和耗能能力。并同时提出了用于分析STRC梁-柱的纤维模型。     

部分外包组合PEC柱强、弱轴滞回性能破坏模式研究分析

通过研究部分外包组合PEC柱在低轴循环荷载试验下,按强、弱轴加栽的2种布置方式的不同破坏模式及其特点。结果表明：强轴PEC柱的破坏是以钢板的屈曲破坏来控制,弱轴PEC柱的破坏是以混凝土的压溃破坏来控制。研究进一步丰富了PEC柱研究成果。为PEC柱应用于实际工程提供了一定的依据。     

Flexural behavior of GFRP-reinforced concrete encased steel composite beams

To improve the ductility and meanwhile ensure satisfactory corrosion-resistant performance, a new type of FRP-reinforced concrete encased steel (FRP-RCS) composite beams comprised of ductile structural steel shapes in combination with corrosion-resistant FRP-reinforced concrete was proposed and studied. An experimental investigation on flexural behavior of the proposed FRP-RCS beams was conducted by testing a total of seven simply supported beam specimens subjected to four-point bending loads. The test specimens included one FRP-reinforced concrete (FRP-RC) beam reinforced with GFRP bars only and six FRP-RCS beams reinforced with both GFRP bars and encased structural steel shapes. The main parameters considered in this study were concrete compressive strength, amounts of GFRP reinforcement as well as ratio and configuration of encased structural steel shapes. The test results indicate that using encased steel shapes can provide a significant enhancement in load carrying capacity, stiffness, ductility and energy absorption capacity of tested beams. The tested FRP-RC beam suffered a brittle failure caused by the sudden fracture of tensile GFRP bars whereas the proposed FRP-RCS beams behaved in a ductile manner mainly due to the beneficial residual strength of encased steel shapes following concrete crushing. In addition, an analytical method was suggested to predict the load carrying capacity of the proposed FRP-RCS beams.     

超高强混凝土型钢组合长柱静力性能试验研究

为解决目前规范中缺乏超高强混凝土型钢组合柱设计方法和静力受压试验研究不够深入的问题,开展了5个轴心受压和4个偏心受压的立方体抗压强度为120 MPa超高强混凝土型钢长柱的静力试验,通过考察其破坏形态、轴力-挠度曲线、轴力-竖向位移曲线和轴力-应变曲线,研究了长细比、相对偏心距和箍筋间距对其静力性能的影响.试验结果表明:...     

钢骨混凝土梁柱框支剪力墙试验与恢复力模型研究

针对工程中经常使用的框支剪力墙结构,提出采用钢骨混凝土转换梁、框支柱对其加强,以改善结构抗震性能。进行了4榀1/4缩尺比例的模型试件拟静力试验,施加竖向荷载和单调及往复水平荷载,其中3榀试件采用钢骨混凝土转换梁和框支柱,1榀试件采用钢筋混凝土转换梁和框支柱。研究了结构承载力、变形、刚度、延性、耗能能力和破坏形态。试验结果表明,结构配置钢骨后各项性能指标均得到改善,延性系数可提高2.29~3.43倍。基于理论公式及试验数据,进一步建立了单调荷载和往复荷载作用下结构三折线型恢复力模型,模型考虑了强度退化和刚度退化,与试验结果较为吻合。     

Q460C高强度钢柱滞回性能有限元分析

为进一步研究Q460C高强度钢柱的滞回性能,在已有试验研究的基础上,采用通用有限元分析软件ANSYS建立了数值模型,对Q460C高强度钢材焊接箱形和H形截面柱在常轴力和水平往复荷载作用下的滞回性能进行模拟,并研究了残余应力对高强度钢试件滞回性能的影响。将有限元分析结果与已有试验结果进行对比,两者吻合较好。研究结果表明：采用提出的Q460C高强度结构钢滞回模型进行有限元分析,能较为准确的预测Q460C高强度钢材焊接H形和箱形柱的滞回性能;试件内残余应力对Q460C高强度钢材焊接H形和箱形截面柱的滞回性能影响较小。     

Seismic behavior of double steel concrete composite walls

An innovative double steel concrete (DSC) composite walls were developed to enhance constructability and lateral load resistance of buildings. In order to research the seismic behavior of DSC composite walls, experimental study was carried out. The high‐strength concrete and high axial load were considered. The failure mode, hysteresis behavior, lateral load‐carrying capacity, deformation, and energy dissipation of the composite walls under different testing parameters were observed. All specimens failed in a flexure behavior, with steel plate buckling and concrete compressive crushing in the bottom of composite walls. The pinching behavior was not significant for hysteresis loops of composite walls. Moreover, the lateral load‐carrying capacity and ductility coefficients increased significantly with spacing of constraining bolts and stiffeners decreased. In addition, the calculation method of the lateral load‐carrying capacity of DSC composite walls was proposed, with the consideration of force equilibrium and moment equilibrium. The finite element (FE) method was performed to analyze the failure process of the specimens with the cyclic load. The concrete damage plastic model was selected to simulate the damage progress of concrete. Validation of the FE models against the experimental results showed good agreement. The effect of different parameters was analyzed with FE models.     

预制装配部分外包混凝土组合梁受弯承载力试验研究

为降低大跨、重荷建筑的建设工程造价,提出一种预制装配部分外包混凝土组合梁(PPECB).设计了7根受弯组合梁试件进行静力试验以研究其受弯性能,考虑浇筑方式、工字钢翼缘厚度、混凝土强度等级、配箍形式对其承载力的影响,研究破坏模式、应变发展和受弯承载力,明确预制装配部分外包混凝土组合梁的破坏机制.结果表明:7根组合梁表现出...     

轴心受压钢筋混凝土柱与外包钢柱有限元对比分析

采用有限元分析软件ANSYS对普通钢筋混凝土轴心受压柱和湿式外包钢加固轴心受压柱进行了相关力学研究,对两种柱在加载过程中混凝土裂缝的发展及混凝土、钢筋和外包钢的应力分布进行了对比分析.研究表明,在提高构件的延性和承载力方面,外包钢骨架发挥了较好的作用.     

冷弯薄壁型钢混凝土剪力墙受剪性能试验研究

通过7个冷弯薄壁型钢混凝土(CTSRC)剪力墙的拟静力水平往复试验,研究了其破坏过程和破坏模式,分析了混凝土强度、剪跨比、轴压比、水平分布筋和竖向型钢量等参数对其受剪性能的影响。试验结果表明：随着水平配筋率、轴压比和混凝土强度的增加受剪承载力提高;随着剪跨比提高,墙体受剪承载力降低;轴压比增加可提高墙体刚度,推迟墙体裂缝的出现,但不利于墙体延性;增加水平配筋可使墙体峰值后的承载力保持稳定。研究表明：CTSRC剪力墙与传统钢筋混凝土剪力墙的破坏特征和受力性能不同,在水平力作用下将出现沿冷弯薄壁型钢的竖向裂缝,经历整体墙到分缝墙的演变,避免了脆性剪切破坏。通过合理设计,CTSRC剪力墙可实现正常使用阶段有较高的刚度、峰值后有较好的延性、破坏时仍具有较高的竖向承载能力的目标。     

Finite element analysis on eccentrically compressive behavior of T-shaped multi-partition steel-concrete composite shear walls with limited width

采用合适的约束混凝土本构关系曲线,建立了T形多腔钢-混凝土组合构件的ABAQUS有限元计算模型,将有限元分析结果与文献试验结果进行对比,二者吻合较好。在验证了有限元模型及选取核心混凝土本构关系曲线可靠性的基础上,利用该有限元模型对T形短肢多腔钢-混凝土组合剪力墙的压弯受力全过程进行了分析。结果表明：在偏压荷载作用下,试件达到峰值荷载之前,多腔钢管已达到承载力,之后核心混凝土所承担的荷载仍继续增加,在试件达到峰值荷载后,核心混凝土达到承载力;与受拉区相比,受压区多腔钢管对核心混凝土的约束作用更为显著;受压区腔体角部核心混凝土强度提高幅度最大,内隔板附近次之,腔体中心处较小。     

波形钢板-混凝土组合剪力墙抗震性能试验研究

为研究波形钢板-混凝土组合剪力墙的抗震性能,完成了竖向波形钢板-混凝土组合剪力墙、水平波形钢板-混凝土组合剪力墙以及平钢板-混凝土组合剪力墙拟静力试验,研究了波形钢板-混凝土组合剪力墙在低周往复荷载作用下的变形能力和破坏模式,分析了荷载-位移滞回曲线、骨架曲线、各阶段特征荷载和位移值等,以及结构的破坏特征、变形和耗能能力、刚度和承载力退化。试验结果表明：波形钢板-混凝土组合剪力墙具有较大的抗侧刚度、较好的延性和耗能能力;与平钢板-混凝土组合剪力墙相比,波形钢板-混凝土组合剪力墙有较好的界面黏结性能,而平钢板-混凝土剪力墙由钢板变形引起的混凝土剥落严重;波形钢板-混凝土组合剪力墙的初始刚度较平钢板-混凝土组合剪力墙的高,竖向波形钢板-混凝土组合剪力墙的承载力和极限位移较水平波形钢板-混凝土组合剪力墙的高,波形钢板-混凝土组合剪力墙的承载力退化和刚度退化比平钢板-混凝土组合剪力墙的慢,表现出较好的受力性能。采用ABAQUS有限元软件可以较好地模拟试验,有限元分析结果表明,波形钢板的应力分布比较均匀,组合作用效应明显,适合在抗震结构中采用。