易修复偏心支撑框架性能与设计方法研究
发布时间：2018-09-11 08:24
【摘要】：偏心支撑框架(Eccentrically Braced Frames)兼具纯框架延性好和中心支撑框架强度刚度高的优点,强震下通过耗能梁段(Link)塑性变形耗能减小结构响应,是高烈度地区高层钢结构首选结构体系之一。但由于耗能梁段自身是框架梁的一部分,因此震后往往难以修复和更换,严重影响了偏心支撑钢框架震后的功能恢复。为提高偏心支撑框架震后功能可恢复性,本文结合某实际工程提出了高强钢外框与软钢腹板相互独立、并联工作,且软钢腹板可更换的新型耗能梁段,并进行了试验和数值解析研究,主要完成的工作和成果如下：(1)进行了四个可更换耗能梁段试件拟静力往复加载试验,结果表明剪力作用下可更换腹板软钢板率先进入塑性耗能,一定转角变形下高强钢翼缘基本保持在弹性阶段,初步设计的可更换耗能梁段承载能力满足工程需求并具备一定的滞回耗能能力。试验中D形试件内端板无螺栓约束段翘曲变形；K形试件连接盖板滑移,并造成试件刚度和承载力下降且滞回曲线捏缩,表明连接部位受力状态对可更换耗能梁段整体力学性能影响显著,应在复合受力状态下严格设计校核。(2)通过ABAQUS对可更换耗能梁段建立精细化有限元模型,其中连接部位建立高强螺栓实体并施加预紧力。有限元模型能够较好地反映可更换耗能梁段各部件在循环加载过程中的力学行为,其中K型试件连接盖板滑移和D型试件内端板无螺栓约束段翘曲变形等试验现象均得到较好模拟,且滞回曲线与试验曲线总体较为吻合。(3)对初步设计的可更换耗能梁段构型进行优化,并通过数值模拟和拟静力往复加载试验进行验证。结果表明,构型优化后的可更换耗能梁段滞回曲线饱满稳定,耗能能力强,合理设计的端板螺栓连接在剪力和弯矩共同作用下能有效保持在弹性阶段。高强钢外框腹板弱化后,其在弯曲变形中保持弹性的能力显著增强,相同转角变形下软钢腹板移除后耗能梁段残余变形明显减小。较短的BLY160软钢腹板可更换耗能梁段超强系数至少达到1.99,明显高于Popov等的建议值；可更换腹板内翼缘角焊缝撕裂是其主要失效模式之一。同时,就关键参数对可更换耗能梁段力学性能的影响进行了数值分析,给出了可更换耗能梁段设计公式和建议。(4)基于构造优化的可更换耗能梁段,提出易修复偏心支撑框架双重结构体系,并通过理论分析提出其设计原则。在ABAQUS中建立了易修复偏心支撑框架多尺度有限元模型,其中可更换耗能梁段采用实体单元建模,框架梁、柱和支撑采用梁单元划分,并通过MPC约束对不同类型单元自由度进行耦合。静力推覆分析和弹塑性动力时程分析结果表明,采用剪切屈服型可更换耗能梁段的易修复偏心支撑框架,其整体刚度主要由框架梁、柱和支撑贡献,可更换耗能梁段弹性刚度变化对结构基本周期和总水平地震作用影响不大。高强钢的使用有效提高了主体框架在地震作用下保持弹性的能力,使结构损伤基本集中在耗能梁段可更换腹板软钢板上；高强钢主体框架在经历较大变形后仍能有效提供弹性恢复力,从而显著减小了腹板移除前后结构的残余变形；在一定的变形范围内,当受损腹板完全移除后,结构将基本实现“自复位”,使软钢腹板可以迅速方便地进行更换。实际强震作用下,合理设计的易修复偏心支撑框架能有效满足罕遇地震下弹塑性层间侧移角限值要求；受损可更换软钢腹板完全移除后,在框架梁、柱和支撑弹性恢复力作用下,各层耗能梁段残余变形均减小至螺栓安装容许误差范围内,从而可以方便快捷地对受损腹板进行更换,显著提高了结构震后功能可恢复性。
[Abstract]:Eccentrically braced frames (Eccentrically Braced Frames) have both the advantages of good ductility of pure frames and high strength and stiffness of central braced frames. It is one of the preferred structural systems for high-rise steel structures in high-intensity regions to reduce structural response through plastic deformation of energy dissipating beam segments (Link) under strong earthquakes. Therefore, it is difficult to repair and replace the eccentrically braced steel frame after earthquake, which seriously affects the functional recovery of the eccentrically braced steel frame after earthquake.In order to improve the functional recovery of the eccentrically braced frame after earthquake, this paper proposes a new type of energy dissipation beam section with high-strength steel outer frame and soft steel web working independently and in parallel, and the soft steel web can be replaced. The main work and achievements are as follows: (1) The quasi-static reciprocating loading tests of four replaceable energy-dissipating beam specimens are carried out. The results show that the replaceable web soft steel plate leads into plastic energy dissipation under shear force, and the high-strength steel flange keeps in elastic stage under certain rotation deformation. The load-carrying capacity of replaceable energy-dissipating beam section meets the engineering requirement and possesses certain hysteretic energy dissipation capacity.In the test,the inner end plate of D-shaped specimen warps without bolt restraint section,the connecting cover plate of K-shaped specimen slips,and the stiffness and load-bearing capacity of the specimen decreases and the hysteretic curve shrinks,which indicates that the stress state of the connecting part is integral to the replaceable energy-dissipating beam section. (2) Fine finite element model of replaceable energy dissipation beam section is established by ABAQUS, in which high-strength bolts are set up at the joints and pre-tightening forces are applied. The finite element model can better reflect the forces of components of replaceable energy dissipation beam section during cyclic loading. The experimental phenomena such as the sliding of the connecting cover plate of K-type specimens and the warping deformation of the non-bolted confinement section of the inner end plate of D-type specimens are well simulated, and the hysteretic curves are in good agreement with the experimental curves. (3) The configuration of the preliminary design of the replaceable energy dissipation beam is optimized, and is advanced by numerical simulation and quasi-static reciprocating loading test. The results show that the hysteretic curves of the replaceable energy dissipation beams with optimized configurations are full and stable, and the energy dissipation capacity is strong. The rationally designed end-plate bolted connections can be effectively maintained in the elastic stage under the combined action of shear force and bending moment. The residual deformation of the energy-dissipating beam section decreases obviously after the removal of the soft steel web. The super-strength coefficient of the replaceable energy-dissipating beam section with the shorter BLY160 steel web is at least 1.99, which is obviously higher than the recommended value of Popov and so on. The tearing of the fillet weld on the inner flange of the replaceable Web is one of the main failure modes. (4) Based on the structural optimization of the replaceable energy dissipation beam section, a dual structure system of eccentrically braced frame is proposed, and its design principle is put forward through theoretical analysis. A multi-scale finite element method of eccentrically braced frame is established in ABAQUS. The model, in which the replaceable beam segment is modeled by solid element, the frame beam, column and brace are divided by beam element, and the different types of element freedom are coupled by MPC constraint. The overall stiffness is mainly contributed by frame beams, columns and braces, and the change of elastic stiffness of replaceable energy dissipation beam has little effect on the basic period and total horizontal seismic action of the structure. In a certain range of deformation, when the damaged web is completely removed, the structure will basically achieve "self-reset" so that the soft steel web can be replaced quickly and conveniently. Under the action of international strong earthquake, the reasonably designed and easily repaired eccentrically braced frame can effectively meet the requirement of elastic-plastic storey lateral displacement angle limit under rare earthquakes. Thus, the damaged web can be replaced conveniently and quickly, and the functional recoverability of the structure after earthquake can be significantly improved.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU391
[Abstract]:Eccentrically braced frames (Eccentrically Braced Frames) have both the advantages of good ductility of pure frames and high strength and stiffness of central braced frames. It is one of the preferred structural systems for high-rise steel structures in high-intensity regions to reduce structural response through plastic deformation of energy dissipating beam segments (Link) under strong earthquakes. Therefore, it is difficult to repair and replace the eccentrically braced steel frame after earthquake, which seriously affects the functional recovery of the eccentrically braced steel frame after earthquake.In order to improve the functional recovery of the eccentrically braced frame after earthquake, this paper proposes a new type of energy dissipation beam section with high-strength steel outer frame and soft steel web working independently and in parallel, and the soft steel web can be replaced. The main work and achievements are as follows: (1) The quasi-static reciprocating loading tests of four replaceable energy-dissipating beam specimens are carried out. The results show that the replaceable web soft steel plate leads into plastic energy dissipation under shear force, and the high-strength steel flange keeps in elastic stage under certain rotation deformation. The load-carrying capacity of replaceable energy-dissipating beam section meets the engineering requirement and possesses certain hysteretic energy dissipation capacity.In the test,the inner end plate of D-shaped specimen warps without bolt restraint section,the connecting cover plate of K-shaped specimen slips,and the stiffness and load-bearing capacity of the specimen decreases and the hysteretic curve shrinks,which indicates that the stress state of the connecting part is integral to the replaceable energy-dissipating beam section. (2) Fine finite element model of replaceable energy dissipation beam section is established by ABAQUS, in which high-strength bolts are set up at the joints and pre-tightening forces are applied. The finite element model can better reflect the forces of components of replaceable energy dissipation beam section during cyclic loading. The experimental phenomena such as the sliding of the connecting cover plate of K-type specimens and the warping deformation of the non-bolted confinement section of the inner end plate of D-type specimens are well simulated, and the hysteretic curves are in good agreement with the experimental curves. (3) The configuration of the preliminary design of the replaceable energy dissipation beam is optimized, and is advanced by numerical simulation and quasi-static reciprocating loading test. The results show that the hysteretic curves of the replaceable energy dissipation beams with optimized configurations are full and stable, and the energy dissipation capacity is strong. The rationally designed end-plate bolted connections can be effectively maintained in the elastic stage under the combined action of shear force and bending moment. The residual deformation of the energy-dissipating beam section decreases obviously after the removal of the soft steel web. The super-strength coefficient of the replaceable energy-dissipating beam section with the shorter BLY160 steel web is at least 1.99, which is obviously higher than the recommended value of Popov and so on. The tearing of the fillet weld on the inner flange of the replaceable Web is one of the main failure modes. (4) Based on the structural optimization of the replaceable energy dissipation beam section, a dual structure system of eccentrically braced frame is proposed, and its design principle is put forward through theoretical analysis. A multi-scale finite element method of eccentrically braced frame is established in ABAQUS. The model, in which the replaceable beam segment is modeled by solid element, the frame beam, column and brace are divided by beam element, and the different types of element freedom are coupled by MPC constraint. The overall stiffness is mainly contributed by frame beams, columns and braces, and the change of elastic stiffness of replaceable energy dissipation beam has little effect on the basic period and total horizontal seismic action of the structure. In a certain range of deformation, when the damaged web is completely removed, the structure will basically achieve "self-reset" so that the soft steel web can be replaced quickly and conveniently. Under the action of international strong earthquake, the reasonably designed and easily repaired eccentrically braced frame can effectively meet the requirement of elastic-plastic storey lateral displacement angle limit under rare earthquakes. Thus, the damaged web can be replaced conveniently and quickly, and the functional recoverability of the structure after earthquake can be significantly improved.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU391
【参考文献】
相关期刊论文 前10条
1 段留省;苏明周;房正刚;王U，
本文编号：2236148
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