变曲率竖曲线钢箱梁顶推过程受力分析
作者:
李传习;陈卓;董创文;李涛
期刊:
公路与汽运 ,2019年(1):116-120+125 ISSN:1671-2668
作者机构:
长沙理工大学土木工程学院;[李涛] 四川路桥建设集团股份有限公司;[董创文; 陈卓; 李传习] 长沙理工大学
关键词:
桥梁;变曲率竖曲线钢箱梁;步履式顶推;受力分析;标高误差
摘要:
以泸州沱江四桥变曲率竖曲线钢箱梁顶推施工为背景,基于单步模数搜索合成法确定的标高调整方案,采用通用有限元软件ANSYS建立钢箱梁顶推全过程杆系模型,对顶推过程中梁体与支墩的受力状态及其对标高调整量误差的敏感性进行分析,研究大跨度变曲率竖曲线钢箱梁顶推过程受力特性。结果表明,钢箱梁顶推过程中,结构的各项受力指标未超过限值,滑道标高调整方案可行,顶推全过程结构受力安全;支点反力对标高调整量很敏感,滑道标高的调整精度宜控制在5 mm以内;当调整工况中出现多个位置同时调整时,各支点调整应分级同步进行。
语种:
中文
展开
Experimental study on torsional behavior of spatial main cable for a self-anchored suspension bridge
作者:
Li, Chuanxi;Li, You;He, Jun*
期刊:
Advances in Structural Engineering ,2019年22(14):3086-3099 ISSN:1369-4332
通讯作者:
He, Jun
作者机构:
[Li, Chuanxi; Li, You; He, Jun] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China;[Li, Chuanxi] Minist Educ, Key Lab Safety Control Bridge Engn, Beijing, Peoples R China;[He, Jun] Heriot Watt Univ, Inst Infrastruct & Environm, Edinburgh, Midlothian, Scotland
通讯机构:
[He, Jun] C;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.
关键词:
main cable;model test;self-anchored suspension bridge;spatial cable;torsional effect;torsional property
摘要:
In order to understand the torsional behavior of the spatial main cable between two saddles for a self-anchored suspension bridge during the transition process from construction state to completed state, a scaled model (1:15) was prepared and tested. First, the cable anchorage system and cable measurement device were designed. Then, a series of model tests under the conditions of different preloading angles and different tensioning forces for hangers were carried out. Finally, the regularity of the torsional properties was revealed on the basis of the measured twist angle of the main cable. The experimental study shows that the transverse pre-deflected angle of the cable clamp has a decisive influence on the torsional angle of the main cable sections near the cable clamp, but for the main cable sections far from the pre-deflected cable clamp, this influence can almost be negligible. The torsional angle changes linearly within adjacent cable clamps. When inclined angle of the hanger is larger than the pre-deflected angle of the cable clamp, the cable clamp will cause the main cable section to twist in the positive direction, otherwise, the result is reverse. With the increase in the hanger force, the direction of hanger force passes through the cross-sectional center of the main cable, resulting in an unchanged twisting angle. In addition, a three-dimensional finite element model of the test specimen was established and used to analyze the influence of pre-deflected angle of a cable clamp on the torsion angle of the main cable, the same results can be found in finite element analyses in comparison with the test results. Therefore, a reasonable pre-deflected angle of cable clamp can be determined by the finite element model in the primary design state before the construction stage.
语种:
英文
展开
平直型钢纤维掺量与长径比对超高性能混凝土性能的影响
作者:
李传习;石家宽;聂洁;曾宇环
期刊:
硅酸盐通报 ,2019年38(9):2947-2954 ISSN:1001-1625
作者机构:
长沙理工大学桥梁工程安全控制教育部重点实验室 长沙410004;[石家宽; 聂洁; 李传习; 曾宇环] 长沙理工大学
关键词:
超高性能混凝土;钢纤维体积掺量;长径比;应力-挠度曲线;弯曲韧性
摘要:
为研究平直型钢纤维体积掺量及长径比对超高性能混凝土(UHPC)施工及力学性能的影响,选用四种镀铜平直型钢纤维,设计并制备了12组不同钢纤维体积掺量(0~4%,长径比均为65)及长径比(65、80、90、100,对应钢纤维体积掺量均为2. 5%)的UHPC试件。通过扩展度、抗压强度和四点弯曲试验,得到了各组UHPC的扩展度、抗压强度、抗折强度及弯曲应力-挠度曲线;基于UHPC弯曲应力-挠度曲线,并结合CECS13∶2009计算了UHPC的弯曲韧性指数。结果表明:随着钢纤维体积掺量的增加,UHPC的扩展度呈下降趋势,UHPC抗压、抗折强度、弯曲韧性指数基本呈增加趋势,对应最佳钢纤维体积掺量分别为4%(平均值174. 4 MPa)、3. 5%(平均值46. 18 MPa)和4%;随着钢纤维长径比的增大(钢纤维体积掺杂量2. 5%不变),UHPC扩展度呈下降趋势,抗压、抗折强度平均值及弯曲韧性指数呈增加趋势;其中,抗压、抗折强度最大值分别为173. 53 MPa和44. 9 MPa。
语种:
中文
展开
A novel method for determining the spatial responses of a cable-stayed bridge with four cable-planes
作者:
Yuan, Peng;Cai, C. S.;Li, Dejian;Xu, Guoji* ;Li, Chuanxi
期刊:
Engineering Structures ,2019年180:223-233 ISSN:0141-0296
通讯作者:
Xu, Guoji
作者机构:
[Yuan, Peng; Li, Dejian] Cent S Univ, Sch Civil Engn, Changsha 410075, Hunan, Peoples R China.;[Cai, C. S.; Yuan, Peng] Louisiana State Univ, Dept Civil & Environm Engn, Baton Rouge, LA 70803 USA.;[Xu, Guoji] Univ Notre Dame, NatHaz Modeling Lab, Notre Dame, IN 46556 USA.;[Li, Chuanxi] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410075, Hunan, Peoples R China.
通讯机构:
[Xu, Guoji] U;Univ Notre Dame, NatHaz Modeling Lab, Notre Dame, IN 46556 USA.
关键词:
Cable-stayed bridge with four cable-planes;Stress envelope diagram;Structural responses;Time-history curve
摘要:
In this paper, a novel method for determining the spatial responses of a cable-stayed bridge with four cable-planes at the design and construction stages is proposed. Herein, the entire construction stage includes many intermediate steps and one completion step. In this method, the spatial responses of the bridge at the design stage (SRBDS) are firstly determined by minimizing the bending and torsion strain energy of the cable-stayed bridge. Simultaneously, the optimal cable forces and the ratios of the inside to outside plane cables are also determined at this stage. Note that the SRBDS are considered as the target responses of the construction stage at the completion step. Then, the Forward process method is used to calculate the spatial responses of the bridge at the construction stage (SRBCS). The least square method is employed to minimize the difference values of the selected control parameters, e.g., cable forces and displacement, between the completion step at the construction stage and the design stage. Finally, the revised results, which satisfy the designated error requirements, are preserved as the SRBCS. To verify the proposed method, an example cable-stayed bridge with four cable-planes and double-girders, the Jiashao bridge, is analyzed. The structural responses, e.g., the stress and displacement of the girder and tower, of the bridge at the design and construction stages are analyzed and compared to demonstrate the superiority of the proposed method and investigate the spatial responses, e.g., the torsion in the main girder, of this cable-stayed bridge with four cable-planes. © 2018 Elsevier Ltd
语种:
英文
展开
某桥支墩基础大体积混凝土温控及参数分析
作者:
张玉平;张亚昕;李传习
期刊:
交通科学与工程 ,2019年35(02):51-57 ISSN:1674-599X
作者机构:
长沙理工大学 土木工程学院,湖南 长沙,410114;[张亚昕; 张玉平; 李传习] 长沙理工大学
关键词:
大体积混凝土;支墩基础;参数分析;间隔期;通水策略
摘要:
为研究大体积混凝土温度变化规律及其控制措施,以太洪长江大桥北岸重力式锚碇支墩基础为工程背景,根据热力学基本原理,建立有限元模型并进行了仿真计算.在施工现场进行了温度实测和控制,并与计算值进行了对比.针对间隔期、冷却水的流速及通水时长3个温控指标进行了参数分析.研究结果表明:该工程分层浇筑的间隔期宜控制在5~7 d.浇筑初期冷却水的流速不应小于1 m/s.温峰过后,可根据降温速率实时调整流速.通水时长至少持续至下个施工阶段结束.
语种:
中文
展开
小半径曲线箱梁非对称增大截面加固分析与试验研究
作者:
肖金军;李传习
期刊:
中外公路 ,2019年39(2):75-79 ISSN:1671-2579
作者机构:
佛山路桥建设有限公司,广东佛山,528002;长沙理工大学省部共建桥梁工程安全控制教育部重点实验室;[肖金军] 佛山市路桥建设有限公司;[李传习] 长沙理工大学
关键词:
曲线箱梁;弯扭耦合;加固;荷载试验;有限元分析
摘要:
曲线箱梁桥最主要的受力特点是弯扭耦合作用,其病害特征和加固方法存在显著的特殊性。该文基于曲线梁桥的3个基本方程,对其力学性能和受力特征进行理论分析,采用有限元软件对某曲线箱梁桥进行计算,分析导致该箱梁腹板开裂、内侧支座脱空、外侧支座偏压严重等病害产生的成因,并对加固后的曲梁桥进行试验测试。结果表明:采用非对称增大截面加固方法,增加两侧腹板厚度等加固措施,能显著提高结构的抗剪扭承载能力,结构受力趋于合理。由于加固箱梁新旧混凝土间存在应力叠加和界面滑移,导致增大截面应变小于原箱梁应变,应力有所滞后。桥梁荷载试验表明该加固措施效果良好。
语种:
中文
展开
三元纤维混掺增强高性能混凝土弯曲韧性及评价方法
作者:
曾宇环;聂洁;李传习;石家宽
期刊:
硅酸盐通报 ,2019年38(8):2614-2621+2630 ISSN:1001-1625
作者机构:
[石家宽; 聂洁; 李传习; 曾宇环] 长沙理工大学
关键词:
三元纤维混掺;弯曲韧性;评价方法;荷载-挠度曲线;应力-应变曲线
摘要:
选用端钩型钢纤维、单丝聚丙烯纤维和纤维素植物纤维,进行了共28组普通素混凝土、单掺、二元及三元纤维混掺增强高性能混凝土的梁三分点加载弯曲韧性试验。绘制了梁受弯荷载-挠度全曲线和底部弯拉应力-应变曲线,结合规范法和文献法分别计算了各纤维混凝土梁的弯曲韧性指标,分析了纤维掺量及混掺方式对混凝土弯曲韧性的影响。结果显示,所有方法计算混凝土弯曲韧性指标结果相近;相较普通素混凝土,纤维的掺入可显著提升混凝土的弯曲韧性,随着纤维掺量增加,三种单掺纤维混凝土试件弯曲韧性指标分别大致呈"先增后减"、"递增"及"递减"趋势;纤维增强混凝土弯曲韧性由强到弱依次为钢纤维,聚丙烯纤维,纤维素纤维;二元纤维混掺时,混凝土弯曲韧性大幅优于素混凝土,而与其对应单掺试件互有增减,当纤维组合为钢纤维1. 92%和聚丙烯纤维0. 4%时,二元纤维混凝土弯曲韧性指标相较单掺纤维混凝土提升最明显;三元纤维混掺时,混凝土弯曲韧性优于所对应单掺、二元混掺试件,其中PCSm值相较普通素混凝土、单掺纤维和二元纤维混掺试件提升1335倍、6. 71倍、1. 89倍;三种纤维最佳体积掺量组合分别为1. 92%,0. 31%和0. 24%。
语种:
中文
展开
U肋双侧焊的钢桥面板残余应力数值分析
作者:
李传习;肖雄;陈卓异
期刊:
交通科学与工程 ,2019年35(02):38-44 ISSN:1674-599X
作者机构:
长沙理工大学 土木工程学院,湖南 长沙,410114;[陈卓异; 肖雄; 李传习] 长沙理工大学
关键词:
正交异性钢桥面板;焊接残余应力;U肋内焊;数值模拟
摘要:
为研究U肋内焊正交异性钢桥面板焊接残余应力的分布规律,采用通用有限元软件ANSYS模拟U肋内焊过程,选用高斯热源模型并采用间接耦合法模拟焊接应力场.将U肋内焊的残余应力场与传统的U肋单侧焊的残余应力场进行了对比分析.研究结果表明:U肋内焊下的双侧焊虽能改变焊缝的偏心状态,但也产生了更加复杂和不利的残余应力场,同时,双侧焊的应力场分布规律与单侧焊的一致.双侧焊的残余应力大于单侧焊的残余应力,其差异在焊缝周围区域表现得更加明显.在设计时,应充分考虑其对结构的影响.
语种:
中文
展开
基于实测车流的钢箱梁横隔板疲劳特性
作者:
李传习;李游;陈卓异;贺君;刘一鸣
期刊:
长安大学学报(自然科学版) ,2019年39(5):48-58 ISSN:1671-8879
作者机构:
长沙理工大学土木工程学院,湖南长沙410114;长沙理工大学桥梁工程安全控制教育部重点实验室,湖南长沙410114;长沙理工大学土木工程学院,湖南长沙,410114;[刘一鸣; 贺君; 陈卓异; 李游; 李传习] 长沙理工大学
关键词:
桥梁工程;车辆荷载谱;模型试验;横隔板弧形切口;疲劳寿命;裂纹扩展
摘要:
为研究车流荷载作用下钢箱梁横隔板弧形切口处母材的疲劳特性,以佛山平胜大桥为背景工程,基于动态称重系统(WIM)监测数据,得到了该桥9种车型的疲劳荷载谱,运用ABAQUS建立了钢箱梁节段模型,计算了横隔板弧形切口处疲劳应力时程曲线。通过模型试验验证,得到了设计弧形切口的疲劳寿命和裂纹扩展规律。研究结果表明:该悬索桥疲劳车型可简化为V2~V10共9类,不同车道的同一车型轴重差异较大,3~#、4~#车道轴重普遍高于1~#、2~#、5~#车道,最大轴重为3~#车道的V10车型的Z3轴,重达151 kN;重车道(3~#、4~#车道)V2~V10车型的比例明显高于其他车道;轮轴作用下弧形切口处沿纵桥向的应力影响线较短,约3个横隔板间距,动力响应始终为压应力,且仅能识别轴组,不能分辨轴组中的单根轴重,当V10车型后轴组通过时,弧形切口的压应力幅达最大,为-169 MPa;考虑车辆超载时,弧形切口处的最小和最大疲劳应力幅分别为不考虑车辆超载时的1.17倍、1.75倍;模型试件在膜压应力幅作用下弧形切口处母材出现疲劳裂纹,开裂位置与实桥一致,均萌生于横隔板弧形切口处起弧点附近,裂纹长度达53 mm;裂纹扩展前期速率较快,后期逐渐减慢;轮载横向作用位置对弧形切口处应力幅影响很大,轮载作用于弧形切口正上方时,该位置应力幅最大。
语种:
中文
展开
国际化新形势下《土木工程概论》双语教学定位初探
作者:
陈卓异;李传习;张玉平;柯红军
期刊:
科技风 ,2019年(24):22 ISSN:1671-7341
作者机构:
长沙理工大学土木工程学院
关键词:
土木工程概论;双语课程;教学定位;教学改革
摘要:
结合土木工程概论的课程特点,开展双语教学的定位探讨,明确双语教学中存在的问题,分析教学目标的定位情况,对国际化新形势下土木工程概论双语教学定位进行实施,验证了双语教学定位的改革效果,为我国土木工程专业培养国际化、复合型人才奠定基础。
语种:
中文
展开
Effects of mechanical properties of adhesive and CFRP on the bond behavior in CFRP-strengthened steel structures
作者:
Li, Chuanxi;Ke, Lu* ;He, Jun* ;Chen, Zhuoyi;Jiao, Yang
期刊:
Composite Structures ,2019年211:163-174 ISSN:0263-8223
通讯作者:
Ke, Lu;He, Jun
作者机构:
[Ke, Lu; He, J; He, Jun; Li, Chuanxi; Chen, Zhuoyi] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.;[Li, Chuanxi; Ke, Lu] Natl Joint Engn Res Lab Longterm Performance Impr, Changsha 410114, Hunan, Peoples R China.;[Jiao, Yang] Arizona State Univ, Mat Sci & Engn, Tempe, AZ 85287 USA.
通讯机构:
[Ke, L; He, J] C;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.
关键词:
Bond behavior;Bond–slip model;Carbon fiber-reinforced polymer;CFRP-steel interface;Steel
摘要:
The bond between carbon fiber-reinforced polymer (CFRP) composites and steel is a key issue in CFRP-strengthened steel structures. The determination of key parameters in the bond strength model remains debatable. We studied the bond behavior between CFRP and steel, focusing on the effects of different types of epoxy adhesive and CFRP on the failure modes, bond–slip relationships, and bond strength parameters. The results show that due to the use of various materials, some specimens fail in interface debonding characterized by brittle failure, whereas others have cohesive failure or CFRP delamination characterized by ductile failure. The bond–slip models showed gentle-slope descending branches for interfaces with ductile failure, which is missing in brittle failure. The bond–slip relationships of most specimens can be simplified as bilinear models. However, trilinear models should be used for the specimens failing in the delamination and tearing of CFRP. As for the modes of interface debonding and CFRP superficial delamination, the maximum shear stresses in the interface linearly correlate with the elastic moduli of adhesive. The nonlinear mechanical behavior of interfaces can be well simulated by a cohesive zone model. © 2018 Elsevier Ltd
语种:
英文
展开
虎门二桥坭洲水道桥近塔区无吊索钢箱梁临时支承体系设计
作者:
谭立心;李传习
期刊:
世界桥梁 ,2019年47(4):6-11 ISSN:1671-7767
作者机构:
长沙理工大学土木与建筑学院,湖南长沙410004;广东省长大公路工程有限公司,广东广州511430;长沙理工大学土木与建筑学院,湖南长沙,410004;[谭立心; 李传习] 长沙理工大学
关键词:
悬索桥;钢箱梁段;临时支承体系;挑梁支架;临时吊索;刚柔结合支承;桥梁施工
摘要:
虎门二桥坭洲水道桥为主跨1688 m的不对称双塔双跨钢箱梁悬索桥.针对近塔区无吊索钢箱梁段的临时支承及线形调节需要,设计了"挑梁支架+临时吊索"的临时支承体系.挑梁支架布置于桥塔下横梁顶部,单幅主梁由2根12 m长的3 H M 588型钢组成,主梁上布置分配梁和轨道梁.挑梁支架临时支承钢箱梁段,并可通过钢滑靴的高度和坡度以及三向千斤顶调整梁段线形.临时吊索由临时索夹、骑跨钢丝绳、螺杆扁担梁、可调节螺杆、连接件组成,既可悬吊支承钢箱梁,又可调节钢箱梁前端标高.全桥钢箱梁段吊装完成后、梁段间环焊施工前,采用临时吊索和布置于挑梁支架上的三向千斤顶调整无吊索梁段的线形及平面位置,环焊使其连接成为整体,再对已成整体的无吊索梁段精调后与合龙段进行环焊施工.
语种:
中文
展开
水胶比对掺粉煤灰超高性能混凝土施工与力学性能影响
作者:
李传习;聂洁;潘仁胜;石家宽;曾宇环
期刊:
硅酸盐通报 ,2019年38(1):14-21 ISSN:1001-1625
作者机构:
[石家宽; 聂洁; 潘仁胜; 李传习; 曾宇环] 长沙理工大学
关键词:
超高性能混凝土;水胶比;施工性能;力学性能;变异性;充分湿拌时间;弯曲韧性
摘要:
使用粉煤灰代替部分水泥有利于减少资源消耗,降低超高性能混凝土(UHPC)造价。同时,水胶比对掺粉煤灰UHPC的施工性能和力学性能具有重要影响。为此,将水胶比设定为唯一变量,研究水胶比对UHPC施工与力学性能的影响规律。开展了水胶比为0. 16~0. 25UHPC的扩展度、抗压强度和弯曲韧性试验,得到了UHPC充分湿拌时间、静停一段时间后的扩展度、抗压、抗折强度和弯曲应力-挠度曲线;对抗压、抗折强度结果进行了变异性分析;基于应力-挠度曲线,并结合CECS 13:2009和Nemkumar法计算了UHPC弯曲韧性指标。试验结果显示:UHPC充分湿拌时间为6 min; UHPC扩展度随水胶比增大基本呈线性增长,且水胶比每增加0. 01,UHPC扩展度平均增幅65 mm;当静停4 h,水胶比分别为0. 16、0. 2、0. 25时,UHPC扩展度损失分别为70 mm、65 mm和50 mm,损失率为21. 5%、10. 4%和5. 5%; UHPC抗压、抗折强度皆随水胶比的增大而减小,两者的变异性无明显规律,但总体而言随着水胶比的增大,两者的变异系数存在减小的趋势,且后者的变异系数大于前者; UHPC的弯曲韧性性能随水胶比的增大而上下波动,并在水胶比为0. 19时达到最优。
语种:
中文
展开
钢箱梁横隔板-U肋交接处割焊残余应力分析
作者:
李传习;熊永明;陈卓异;柯璐;宋钢兵
期刊:
桥梁建设 ,2019年49(5):27-32 ISSN:1003-4722
作者机构:
[李传习; 熊永明; 陈卓异; 柯璐] Key Laboratory for Safety Control of Bridge Engineering, Ministry of Education, Changsha University of Science & Technology, Changsha;410114, China;[宋钢兵] University of Houston, Houston;77204-4006, United States;[李传习; 熊永明; 陈卓异; 柯璐] 410114, China
关键词:
钢箱梁;正交异性板;横隔板;焊接;热切割;残余应力;有限元法
摘要:
为研究钢箱梁正交异性桥面板横隔板与U肋交接处的残余应力分布规律,采用Abaqus有限元软件模拟横隔板的热切割和焊接过程,分析横隔板与U肋交接处热残余应力的分布特征,探讨切割速度和焊接速度对横隔板弧形切口处残余应力的影响。结果表明:横隔板弧形切口处产生切向残余拉应力,其值超过钢材屈服强度;焊接在横隔板与U肋焊接区局部范围引起沿焊缝方向的残余拉应力,且焊缝尾端的应力集中更为明显;弧形切口残余应力区宽度随切割速度的增加而减小,残余拉应力随焊接速度的增加而增大;选用较快的横隔板切割速度和较慢的焊接速度可减小弧形切口处残余应力分布宽度和应力值。
语种:
中文
展开
基于规范理解的正交异性钢桥面横隔板弧形缺口局部区域疲劳验算
作者:
郭立成;冯峥;李传习;陈卓异
期刊:
中外公路 ,2019年39(4):77-82 ISSN:1671-2579
作者机构:
长沙理工大学桥梁工程安全控制教育部重点实验室,湖南长沙410114;佛山市路桥建设有限公司;长沙理工大学桥梁工程安全控制教育部重点实验室,湖南长沙,410114;[冯峥; 陈卓异; 李传习; 郭立成] 长沙理工大学
关键词:
桥梁工程;正交异性桥面板;钢箱梁横隔板弧形缺口;公路钢结构桥梁设计规范;名义应力法
摘要:
针对横隔板弧形缺口局部区域疲劳开裂问题严重,采用名义应力法进行疲劳验算名义应力难以确定,以及中国JTG D64 2015《公路钢结构桥梁设计规范》关于名义应力表述不清等问题,探讨了基于规范的正交异性钢桥面横隔板弧形缺口局部区域的疲劳验算方法。首先,对比分析了 JTG D64-2015《公路钢结构桥梁设计规范》(后文称《公路钢桥规》)与欧洲Eurocode规范的各疲劳设计条款的异同,指出了中国《公路钢桥规》各疲劳设计条款的主要来源及其与欧洲规范各疲劳设计条款的相应关系,以及中国规范中抗疲劳设计条款的不足;其次,介绍了欧洲规范关于横隔板弧形缺口母材处以及横隔板与U肋连接处角焊缝名义应力的相关计算方法;最后,通过算例介绍了如何应用名义应力法验算横隔板弧形缺口母材以及角焊缝处的疲劳强度。
语种:
中文
展开
薄壁箱梁约束扭转的有限元分析及弯扭力矩新算法
作者:
夏桂云;李传习;杨美良
期刊:
湖南大学学报(自然科学版) ,2019年46(1):85-92 ISSN:1674-2974
通讯作者:
Xia, G.
作者机构:
[夏桂云; 李传习; 杨美良] School of Civil Engineering, Changsha University of Science and Technology, Changsha, 410114, China
通讯机构:
School of Civil Engineering, Changsha University of Science and Technology, Changsha, China
关键词:
薄壁结构;约束扭矩;有限元分析;双力矩;扭率;新算法
摘要:
利用初参数法和传递矩阵,建立了薄壁箱梁约束扭转分析的有限元列式,导出了均布扭矩和均布双力矩的非结点荷载的等效公式.基于约束扭转的有限元位移解,进一步建立了弯扭力矩新算法,导出相应的刚度矩阵、均布扭矩和均布双力矩作用下的固端力公式,方便正应力和剪应力的计算.算例表明,本文的计算结果与理论值完全符合,所建立的薄壁箱梁约束扭转有限元列式、均布扭矩和均布双力矩的非结点荷载等效公式、弯扭力矩新算法公式正确.
语种:
中文
展开
Experimental Study on Shear Performance of Cast-In-Place Ultra-High Performance Concrete Structures
作者:
Li, Chuanxi;Feng, Zheng* ;Ke, Lu;Pan, Rensheng* ;Nie, Jie
期刊:
Materials ,2019年12(19):1-16 ISSN:1996-1944
通讯作者:
Feng, Zheng;Pan, Rensheng
作者机构:
[Feng, Zheng; Nie, Jie; Feng, Z; Pan, Rensheng; Li, Chuanxi; Ke, Lu] Changsha Univ Sci & Technol, Dept Educ, Key Laboratary Bridge Engn Safety Control, Changsha 410114, Hunan, Peoples R China.;[Feng, Zheng; Nie, Jie; Feng, Z; Pan, Rensheng; Li, Chuanxi; Ke, Lu] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.
通讯机构:
[Feng, Z; Pan, RS] C;Changsha Univ Sci & Technol, Dept Educ, Key Laboratary Bridge Engn Safety Control, Changsha 410114, Hunan, Peoples R China.;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.
关键词:
Cast in place concrete;Compressive strength;Ductility;High performance concrete;Reinforced plastics;Shear flow;Shear strength;Volume fraction;Cast in place;Direct shear strength;Fiber volume fractions;Shear performance;Shear properties;Steel fiber shapes;Strength and ductilities;Ultra high performance concretes;Steel fibers
摘要:
In order to study the direct shear properties of ultra-high performance concrete (UHPC) structures, 15 Z-shaped monolithic placement specimens (MPSs) and 12 Z-shaped waterjet treated specimens (WJTSs) were tested to study the shear behavior and failure modes. The effects of steel fiber shape, steel fiber volume fraction and interface treatment on the direct shear properties of UHPC were investigated. The test results demonstrate that the MPSs were reinforced with steel fibers and underwent ductile failure. The ultimate load of the MPS is about 166.9% of the initial cracking load. However, the WJTSs failed in a typical brittle mode. Increasing the fiber volume fraction significantly improves the shear strength, which can reach 24.72 MPa. The steel fiber type has little effect on the shear strength and ductility, while increasing the length of steel fibers improves its ductility and slightly reduces the shear strength. The direct shear strength of the WJTSs made from 16 mm hooked-type steel fibers can reach 9.15 MPa, which is 2.47 times the direct shear strength of the specimens without fibers. Finally, an interaction formula for the shear and compressive strength was proposed on the basis of the experimental results, to predict the shear load-carrying capacity of the cast-in-place UHPC structures. © 2019 by the authors.
语种:
英文
展开
A Simplified Calculation Method of Length Adjustment of Datum Strand for the Main Cable with Small Sag
作者:
He, Jun* ;Li, Chuanxi;Ke, Hongjun;Liu, Yang;Zhang, Yuping;...
期刊:
Advances in Civil Engineering ,2019年2019(3):1-8 ISSN:1687-8086
通讯作者:
He, Jun
作者机构:
[Zhang, Yuping; He, Jun; Li, Chuanxi; Dong, Chuangwen; Li, Hongli; Liu, Yang; Ke, Hongjun] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.;[Zhang, Zhe] Dalian Univ Technol, Sch Civil Engn, Dalian 116024, Peoples R China.
通讯机构:
[He, Jun] C;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.
摘要:
In order to overcome the complicated iterative process of the cable length adjustment based on catenary theory and large error of length adjustment for cable with a small sag based on the parabola theory, this paper firstly develops a direct and simply calculation method based on parabola theory, considering the influence of elastic elongation on the cable unstressed length, which can apply for datum strand of the main cable and catwalk bearing rope with a small sag to improve the construction accuracy of the datum strand of suspension bridges. Then, the applicability of the proposed cable length adjustment formula under different conditions of the sag-span ratio is analyzed and compared with other calculation methods based on the theory of catenary or parabola. Finally, numerical examples are presented and discussed to illustrate the accuracy and efficiency of the proposed analytical method.
语种:
英文
展开
Enhanced comprehensive performance of bonding interface between CFRP and steel by a novel film adhesive
作者:
Ke, Lu;Li, Chuanxi* ;Luo, Nanhai;He, Jun;Jiao, Yang;...
期刊:
Composite Structures ,2019年229:111393 ISSN:0263-8223
通讯作者:
Li, Chuanxi
作者机构:
[Ke, Lu; Li, Chuanxi] Changsha Univ Sci & Technol, Dept Educ, Key Lab Bridge Engn Safety Control, Changsha 410114, Hunan, Peoples R China.;[He, Jun; Ke, Lu; Li, Chuanxi; Luo, Nanhai] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.;[Jiao, Yang; Ke, Lu] Arizona State Univ, Mat Sci & Engn, Tempe, AZ 85287 USA.;[He, Jun] Heriot Watt Univ, Inst Infrastruct & Environm, Edinburgh EH14 4AS, Currie, Scotland.;[Liu, Yongming] Arizona State Univ, Aerosp & Mech Engn, Tempe, AZ 85287 USA.
通讯机构:
[Li, Chuanxi] C;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.
关键词:
Bond performance;Bond-slip relationship;Carbon fiber reinforced polymer (CFRP);Film adhesive;Steel
摘要:
A novel film adhesive was proposed to bond carbon fiber reinforced polymer (CFRP) laminas to steel substrates, and experimental validations for improved comprehensive bond performances are presented. This film adhesive was shown to possess excellent high-temperature resistance via dynamic mechanical analysis (DMA). A series of CFRP/steel double-lap joints (DLJs) with different bond lengths were experimentally studied, focusing on the failure modes, effective bond length, bond-slip relationship, and bond strength. The results show that the film-adhesive bonded joints fail in the mode of CFRP delamination, which indicates a stronger interfacial bond between the adhesive layer and adherends than the intra-laminar strength of CFRPs. The bonding interface has an effective bond length of approximately 65 mm, beyond which no increase of ultimate load can be achieved with the increase of bond length. The bond-slip relationship of the film-adhesive bonding interface exhibits a trapezoidal (ductile) shape, which is significantly different from the triangular (brittle) shapes for most paste-adhesive interfaces. Superior strength, ductility, and high-temperature resistance of the bonding interfaces in CFRP/steel composites are achieved due to the use of this film adhesive. The proposed study offers an alternative solution to an enhanced comprehensive property of the bonding interface in CFRP/steel composites. © 2019 Elsevier Ltd
语种:
英文
展开
《土木工程概论》双语课程的多层次评价体系探讨
作者:
陈卓异;李传习;张玉平;柯红军
期刊:
科技风 ,2019年(28):47 ISSN:1671-7341
作者机构:
长沙理工大学土木工程学院 湖南长沙 410114;[柯红军; 张玉平; 陈卓异; 李传习] 长沙理工大学
关键词:
土木工程概论;双语课程;评价体系
摘要:
对《土木工程概论》的教学效果进行评价是衡量教学质量的重要指标.通过对双语课程评价体系进行分析,从三个方面实施土木工程概论双语课程多层次评价体系,发现多层次评价体系改革效果良好,对教学效果具有促进作用.
语种:
中文
展开