易修復(fù)偏心支撐框架性能與設(shè)計(jì)方法研究
發(fā)布時間：2018-09-11 08:24
【摘要】：偏心支撐框架(Eccentrically Braced Frames)兼具純框架延性好和中心支撐框架強(qiáng)度剛度高的優(yōu)點(diǎn),強(qiáng)震下通過耗能梁段(Link)塑性變形耗能減小結(jié)構(gòu)響應(yīng),是高烈度地區(qū)高層鋼結(jié)構(gòu)首選結(jié)構(gòu)體系之一。但由于耗能梁段自身是框架梁的一部分,因此震后往往難以修復(fù)和更換,嚴(yán)重影響了偏心支撐鋼框架震后的功能恢復(fù)。為提高偏心支撐框架震后功能可恢復(fù)性,本文結(jié)合某實(shí)際工程提出了高強(qiáng)鋼外框與軟鋼腹板相互獨(dú)立、并聯(lián)工作,且軟鋼腹板可更換的新型耗能梁段,并進(jìn)行了試驗(yàn)和數(shù)值解析研究,主要完成的工作和成果如下：(1)進(jìn)行了四個可更換耗能梁段試件擬靜力往復(fù)加載試驗(yàn),結(jié)果表明剪力作用下可更換腹板軟鋼板率先進(jìn)入塑性耗能,一定轉(zhuǎn)角變形下高強(qiáng)鋼翼緣基本保持在彈性階段,初步設(shè)計(jì)的可更換耗能梁段承載能力滿足工程需求并具備一定的滯回耗能能力。試驗(yàn)中D形試件內(nèi)端板無螺栓約束段翹曲變形；K形試件連接蓋板滑移,并造成試件剛度和承載力下降且滯回曲線捏縮,表明連接部位受力狀態(tài)對可更換耗能梁段整體力學(xué)性能影響顯著,應(yīng)在復(fù)合受力狀態(tài)下嚴(yán)格設(shè)計(jì)校核。(2)通過ABAQUS對可更換耗能梁段建立精細(xì)化有限元模型,其中連接部位建立高強(qiáng)螺栓實(shí)體并施加預(yù)緊力。有限元模型能夠較好地反映可更換耗能梁段各部件在循環(huán)加載過程中的力學(xué)行為,其中K型試件連接蓋板滑移和D型試件內(nèi)端板無螺栓約束段翹曲變形等試驗(yàn)現(xiàn)象均得到較好模擬,且滯回曲線與試驗(yàn)曲線總體較為吻合。(3)對初步設(shè)計(jì)的可更換耗能梁段構(gòu)型進(jìn)行優(yōu)化,并通過數(shù)值模擬和擬靜力往復(fù)加載試驗(yàn)進(jìn)行驗(yàn)證。結(jié)果表明,構(gòu)型優(yōu)化后的可更換耗能梁段滯回曲線飽滿穩(wěn)定,耗能能力強(qiáng),合理設(shè)計(jì)的端板螺栓連接在剪力和彎矩共同作用下能有效保持在彈性階段。高強(qiáng)鋼外框腹板弱化后,其在彎曲變形中保持彈性的能力顯著增強(qiáng),相同轉(zhuǎn)角變形下軟鋼腹板移除后耗能梁段殘余變形明顯減小。較短的BLY160軟鋼腹板可更換耗能梁段超強(qiáng)系數(shù)至少達(dá)到1.99,明顯高于Popov等的建議值；可更換腹板內(nèi)翼緣角焊縫撕裂是其主要失效模式之一。同時,就關(guān)鍵參數(shù)對可更換耗能梁段力學(xué)性能的影響進(jìn)行了數(shù)值分析,給出了可更換耗能梁段設(shè)計(jì)公式和建議。(4)基于構(gòu)造優(yōu)化的可更換耗能梁段,提出易修復(fù)偏心支撐框架雙重結(jié)構(gòu)體系,并通過理論分析提出其設(shè)計(jì)原則。在ABAQUS中建立了易修復(fù)偏心支撐框架多尺度有限元模型,其中可更換耗能梁段采用實(shí)體單元建模,框架梁、柱和支撐采用梁單元劃分,并通過MPC約束對不同類型單元自由度進(jìn)行耦合。靜力推覆分析和彈塑性動力時程分析結(jié)果表明,采用剪切屈服型可更換耗能梁段的易修復(fù)偏心支撐框架,其整體剛度主要由框架梁、柱和支撐貢獻(xiàn),可更換耗能梁段彈性剛度變化對結(jié)構(gòu)基本周期和總水平地震作用影響不大。高強(qiáng)鋼的使用有效提高了主體框架在地震作用下保持彈性的能力,使結(jié)構(gòu)損傷基本集中在耗能梁段可更換腹板軟鋼板上；高強(qiáng)鋼主體框架在經(jīng)歷較大變形后仍能有效提供彈性恢復(fù)力,從而顯著減小了腹板移除前后結(jié)構(gòu)的殘余變形；在一定的變形范圍內(nèi),當(dāng)受損腹板完全移除后,結(jié)構(gòu)將基本實(shí)現(xiàn)“自復(fù)位”,使軟鋼腹板可以迅速方便地進(jìn)行更換。實(shí)際強(qiáng)震作用下,合理設(shè)計(jì)的易修復(fù)偏心支撐框架能有效滿足罕遇地震下彈塑性層間側(cè)移角限值要求；受損可更換軟鋼腹板完全移除后,在框架梁、柱和支撐彈性恢復(fù)力作用下,各層耗能梁段殘余變形均減小至螺栓安裝容許誤差范圍內(nèi),從而可以方便快捷地對受損腹板進(jìn)行更換,顯著提高了結(jié)構(gòu)震后功能可恢復(fù)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.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：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.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TU391
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 段留省;蘇明周;房正剛;王U，
本文編號：2236148
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