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MODIFICATON AND RESEARCH ON BENDING RIGIDITY FORMULA OF REINFORCED CONCRETE BEAM
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作者 艾军 陈珏 +1 位作者 张丽芳 刘芳 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第4期299-305,共7页
Beam stiffness degrades with its age in service and its service performance is weakened.According to the fundamental characteristics of the reinforced concrete,the influence of stiffness degradation caused by differen... Beam stiffness degrades with its age in service and its service performance is weakened.According to the fundamental characteristics of the reinforced concrete,the influence of stiffness degradation caused by different kinds of damage is obtained.Among them,the crack is the most direct and obvious factor.Furthermore,according to the analysis of bending rigidity formula presented in current standard,an influence parameter of crack development on the stiffness degradation,i.e.,nonuniformity coefficient of tensile steel strain φ,is extracted.Average crack distance and crack depth are taken as crack statistic parameters.Based on analysis and modeling with ANSYS,the modified bending rigidity formula related to crack is obtained. 展开更多
关键词 reinforced concrete beam and girders STIFFNESS CRACK ANSYS
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Behavior of reinforced concrete beams and columns subjected to blast loading 被引量:10
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作者 Yan Liu Jun-bo Yan Feng-lei Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第5期550-559,共10页
In this study, the blast performance of steel reinforced concrete(RC) beams was experimentally and analytically investigated. The experiment consists of a total of 10 one-half-scale beams subjected to different levels... In this study, the blast performance of steel reinforced concrete(RC) beams was experimentally and analytically investigated. The experiment consists of a total of 10 one-half-scale beams subjected to different levels of blast loading using live explosives. The reflected pressure-time histories were recorded and different damage levels and modes were observed. The blast resilience of the damaged beams was quantified by measuring the time-dependent displacements. Experiment results show that the damage in steel reinforced concrete beams with higher explosive mass is enhanced compared with that of the beams with smaller explosive mass at the same scaled distance. Based on the experiment data, an empirical expression is developed via dimensional analysis to correct the relationship between the midspan displacement and scaled distance. Besides, a complex single degree of freedom model(SDOF)incorporating complex features of the material behavior, high strain-rate effect and the column geometry was proposed and validated by test results. 展开更多
关键词 BLAST Steel reinforced concrete beamS Dynamic response SCALING SDOF
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Experimental investigation of p-section concrete beams under contact explosion and close-in explosion conditions 被引量:5
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作者 Zhen Li Yan Liu +2 位作者 Jun-bo Yan Wen-li Yu Feng-lei Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第5期540-549,共10页
This paper presents the results of an experimental investigation on explosive breaching of p-section concrete beams. Twenty three p-section concrete beams with a 100 cm length were tested. TNT charges were placed at t... This paper presents the results of an experimental investigation on explosive breaching of p-section concrete beams. Twenty three p-section concrete beams with a 100 cm length were tested. TNT charges were placed at three positions: contact detonation in the center, contact detonation above the web and close-in detonation in the center. The external and internal breach parameters of the panels were evaluated by measuring the diameter of the ejection crater, spalling crater and breach hole created by the charge detonation. The experimental results were compared to predict values obtained by the analytical models proposed by McVay, Morishita and Remennikov. A modified breach with crater limit line and breach without crater limit line were put forward based on the experimental results. The maximum cross-sectional destruction area ratio(MCDAR) values were used to evaluate the damage degree. The maximum value of MCDAR reached 0.331 corresponding to the C5 experimental condition, of which explosion occurred above the web. 展开更多
关键词 P-section concrete beam CONTACT explosion Close-in explosion EXPLOSIVE breach
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Dynamic responses of reinforced concrete beams under double-endinitiated close-in explosion 被引量:4
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作者 Bin Rao Li Chen +3 位作者 Qin Fang Jian Hong Zhong-xian Liu Heng-bo Xiang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第5期527-539,共13页
The reinforced concrete(RC) structural component might suffer a great damage under close-in explosion.Different from distant explosions, blast loads generated by the close-in explosion are non-uniformly distributed on... The reinforced concrete(RC) structural component might suffer a great damage under close-in explosion.Different from distant explosions, blast loads generated by the close-in explosion are non-uniformly distributed on the structural component and may cause both local and structural failure. In this study,an experimental study was conducted to investigate the dynamic responses of RC beams under doubleend-initiated close-in explosions. The experimental results show that the distribution of blast loads generated by the double-end-initiated explosion is much more non-uniform than those generated by single-point detonation, which is caused by the self-Mach-reflection effects. A 3 D finite element model was developed and validated in LS-DYNA by employing the modified K&C model. Intensive numerical calculations were conducted to study the influences of the initiation way, scaled distance and longitudinal reinforcement ratio on the dynamic responses and failure modes of RC beams. Numerical results show that the RC beam suffers greater damage as the cylindrical explosive is detonated at its double ends than the scenario in which the cylindrical explosive is detonated at its central point. RC beams mainly suffer flexural failure and flexure-shear failure under the double-end close-in explosion, and the failure modes of RC beams change from the flexural damage to flexure-shear damage as the scaled distance or the longitudinal reinforcement ratio decreases. The direct shear failure mode is not usually observed in the double-end-initiated explosion, since the intense blast loads is basically concentrated in the midspan of RC beam, which is due to self-Mach-reflection enhancement. 展开更多
关键词 REINFORCED concrete(RC)beam Close-in explosion Failure mode Dynamic response Double-end-initiation
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Structural Behavior of Continuous Prestressed Steel Fiber Reinforced High Strength Concrete Beam 被引量:2
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作者 刘海波 向天宇 赵人达 《Journal of Southwest Jiaotong University(English Edition)》 2008年第1期37-45,共9页
The flexural behaviors of continuous fully and partially prestressed steel fiber reinforced high strength concrete beams are studied by experiment and nonlinear finite element analysis. Three levels of partial prestre... The flexural behaviors of continuous fully and partially prestressed steel fiber reinforced high strength concrete beams are studied by experiment and nonlinear finite element analysis. Three levels of partial prestress ratio (PPR) are considered, and three pairs of two-span continuous beams with box sections varying in size are designed. The major parameters involved in the study include the PPR and the fiber location. It is concluded that the prestressed high strength concrete beam exhibits satisfactory ductility; the influences of steel fiber on the crack behaviors for partially prestressed beams are not as obvious as those for fully prestressed ones; steel fibers can improve the structural stiffness after cracking for fully prestressed high strength concrete beams; the moment redistribution from mid-span to intermediate support in the first stage should be mainly considered in practical design. 展开更多
关键词 High strength concrete Steel fiber reinforced concrete Prestressed concrete Continuous beam
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Fatigue Damage Modeling for Partially Prestressed Concrete Beams under Repeated Loadings with Variable Amplitude 被引量:2
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作者 冯秀峰 宋玉普 朱美春 《Journal of Southwest Jiaotong University(English Edition)》 2006年第3期258-264,共7页
A full-range nonlinear analysis method for fatigue damage in prestressed concrete beams is presented. New damage accumulation models are proposed to describe the fatigue damage evolution in concrete and reinforcement ... A full-range nonlinear analysis method for fatigue damage in prestressed concrete beams is presented. New damage accumulation models are proposed to describe the fatigue damage evolution in concrete and reinforcement respectively. Based on the stress analysis for cross section, the stress redistrbution in the fatigue damage process, due to the different damage mechanisms of concrete and reinforcement, is considered. The nonlinear damage analysis is achieved by means of piecewise linearity, and it is applicable on the condition of repeated loadings with variable amplitude. Fatigue damage modeling of a beam is implemented to illustrate that the proposed method can preferably fit the experimental results. 展开更多
关键词 Prestressed concrete beam FATIGUE DAMAGE Nonlinear analysis Stress redistribution
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Behavior of Corrosion-Repaired Concrete Beams Reinforced by Epoxy Mortar 被引量:1
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作者 Wu Jin Tang Jinzhi +2 位作者 Li Hongming Shang Baokang Wang Zhe 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2016年第3期395-402,共8页
The performance of concrete beams repaired with epoxy mortar was investigated by constructing twelve beam specimens.All the beam specimens were subjected to a constant current for accelerated corrosion.Six specimens w... The performance of concrete beams repaired with epoxy mortar was investigated by constructing twelve beam specimens.All the beam specimens were subjected to a constant current for accelerated corrosion.Six specimens were corroded without subsequent reparation as a control group,and the other six beam specimens were corroded and repaired utilizing epoxy mortar.All specimens were tested to failure.During test process,we focused on the failure pattern of beam specimens,structural cracks,mid-deflections,bearing capacity,and probed into the influence of corrosion degree and repair of epoxy mortar on the performance of beam specimens.It was observed that corrosion-repaired beams in the loading test were in a bending failure pattern.It is obvious that cracking loads and bending stiffness of repaired beams and corrosion-repaired beams were larger than those of unrepaired beams and secondly-corroded beams.When the mass loss of main steel bars was smaller than 10%,the bearing capacity of the repaired beams was similar to that of the unrepaired beams.When the mass loss of main steel bars was larger than 10%,the bearing capacity of the repaired beams increased significantly compared with that of the unrepaired beams. 展开更多
关键词 CORROSION steel bars concrete beams epoxy mortar loading test
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Performance of Epoxy-Repaired Corroded Reinforced Concrete Beams 被引量:1
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作者 李洪明 吴瑾 +1 位作者 王喆 尚保康 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第5期579-584,共6页
Reinforcement corrosion has a serious impact on the durability and safety of reinforced concrete structures.Six reinforced concrete(RC)beam specimens are constructed.After beam specimens are subjected to accelerated c... Reinforcement corrosion has a serious impact on the durability and safety of reinforced concrete structures.Six reinforced concrete(RC)beam specimens are constructed.After beam specimens are subjected to accelerated corrosion with the constant current,beam specimens are repaired with epoxy mortar and the flexural test of beams is investigated.Then the behaviors of repaired corroded reinforced concrete beams are evaluated.The experimental results show that cracking and ultimate loads of corroded RC beams are enhanced after being repaired.And the strain distributions measured across sections of beam specimens still obey the assumption of plane section.After being repaired,the number of cracks decreases and the crack spacing increases. 展开更多
关键词 CORROSION reinforced concrete beam epoxy mortar flexural behavior REPAIR
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Experimental and theoretical analysis on the natural frequency of external prestressed concrete beams 被引量:1
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作者 熊辉霞 《Journal of Chongqing University》 CAS 2008年第4期317-323,共7页
Analyses and computations of the natural frequencies of external prestressed concrete structures are the bases for studying the dynamic properties of such structures. We carded out dynamic tests on three types of exte... Analyses and computations of the natural frequencies of external prestressed concrete structures are the bases for studying the dynamic properties of such structures. We carded out dynamic tests on three types of external simply supported beams, pulling the beams gradually. Then vertical loads were applied to the beams while the frequencies and related coefficients were measured at every step. We calculated natural frequencies and the results indicate that natural frequencies increase as the prestressing force rises in the pre-crack stage, and decrease significantly during the post-crack stage. Substantial incoincidences exist between the calculated and experimental results for the frequency and its tendency to changel Based on the experimental results, we modified the stiffness and other parameters in the equations. The results calculated using the modified equations agree with experimental results well, so the modified eauations can be used nractically. 展开更多
关键词 natural frequency external prestressed concrete beams dynamic property stiffness modification
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Flexural rigidity evolvement laws of reinforced concrete beams strengthened with carbon fiber laminates
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作者 牛鹏志 《Journal of Chongqing University》 CAS 2007年第1期67-72,共6页
Extensive research has shown that externally bonded carbon fiber reinforced polymer (CFRP) laminates are particularly suitable for improving the fatigue behavior of reinforced concrete (RC) beams. This paper prese... Extensive research has shown that externally bonded carbon fiber reinforced polymer (CFRP) laminates are particularly suitable for improving the fatigue behavior of reinforced concrete (RC) beams. This paper presents the research on flexural ngidity evolvement laws by testing 14 simple-supported RC beams strengthened with carbon fiber laminates (CFL) under cyclic load, and 2 under monotone load as a reference. The cyclic load tests revealed the peak load applied onto the surface of a supported RC beam strengthened with CFL is linear to the logarithm of its fatigue life, and the flexural rigidity evolvement undergoes three distinct phases: a rapid decrease from the start to about 5% of the fatigue life; an even development from .5% to about 99% of the fatigue life; and a succedent rapid decrease to failure. When the ratio of fatigue "cycles to the fatigue life is within 0.0.5 to 0.99, the flexural rigidity varies linearly with the ratio. The peak load does not affect the flexural rigidity evolvement if it is not high enough to make the main reinforcements yield. The dependences of the flexural rigidity of specimens formed in the same group upon their fatigue cycles normalized by fatigue life are almost coincident. This implies the flexural rigidity may be a material parameter independent of the stress level. These relationships of flexural rigidity to fatigue cycles, and fatigue life may be able to provide some hints for fatigue design and fatigue life evaluation of RC member strengthened with CFL; nevertheless the findings still need verifying by more experiments. 展开更多
关键词 flexural rigidity carbon fiber laminate reinforced concrete beam FATIGUE
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The Design and Analysis of Long-Span and Low-Depth Prestressed Composite Steel-Concrete Beam Bridge
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作者 张俊平 黄海云 黄道沸 《Journal of Southwest Jiaotong University(English Edition)》 2002年第1期57-67,共11页
The design scheme of long span and low depth composite steel concrete beams is introduced, and the methods of avoiding the cracking of concrete deck in the negative moment regions are proposed. Moreover, significa... The design scheme of long span and low depth composite steel concrete beams is introduced, and the methods of avoiding the cracking of concrete deck in the negative moment regions are proposed. Moreover, significant exploration for problems of the composite beams has been made, such as optimizing construction steps to regulate the stress, applying jacking technique to exert prestress on the concrete deck, investigating the uplifting force principle of the shear connectors by means of model test and non linear finite element analysis, and pointing out the countermeasure to reduce tension force of the shear connectors. 展开更多
关键词 prestressed composite steel concrete beam construction step jacking technique shear connector
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Shear strengthening of pre-damaged reinforced concrete beams with carbon fiber reinforced polymer sheet strips
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作者 Feras ALZOUBI 《Journal of Chongqing University》 CAS 2007年第4期305-310,共6页
This paper presents the results of an experimental investigation on the response of pre-damaged reinforced concrete (RC) beam strengthened in shear using applied-epoxy unidirectional carbon fiber reinforced polymer ... This paper presents the results of an experimental investigation on the response of pre-damaged reinforced concrete (RC) beam strengthened in shear using applied-epoxy unidirectional carbon fiber reinforced polymer (CFRP) sheet. The reasearch included four test rectangular simply supported RC beams in shear capacity. One is the control beam, two RC beams are damaged to a predetermined degree from ultimate shear capacity of the control beam, and the last beam is left without pre-damaged and then strengthened with using externally bonded carbon fiber reinforced polymer to upgrade their shear capacity. We focused on the damage degree to beams during strengthening, therefore, only the beams with sidebonded CFRPs strips and horizontal anchored strips were used. The results show the feasibility of using CFRPs to restore or increase the load-carrying capacity in the shear of damaged RC beams. The failure mode of all the CFRP-strengthened beams is debonding of CFRP vertical strips. Two prediction available models in AC1-440 and fib European code were compared with the experimental results. 展开更多
关键词 reinforced concrete beam carbon fiber reinforced polymer shear strength
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Resistance of full-scale beams against close-in explosions.Numerical modeling and field tests
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作者 A.Prado A.Alañón +5 位作者 R.Castedo A.P.Santos L.M.López M.Chiquito M.Bermejo C.Oggeri 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期35-47,共13页
This paper explores the performances of a finite element simulation including four concrete models applied to a full-scale reinforced concrete beam subjected to blast loading. Field test data has been used to compare ... This paper explores the performances of a finite element simulation including four concrete models applied to a full-scale reinforced concrete beam subjected to blast loading. Field test data has been used to compare model results for each case. The numerical modelling has been, carried out using the suitable code LS-DYNA. This code integrates blast load routine(CONWEP) for the explosive description and four different material models for the concrete including: Karagozian & Case Concrete, Winfrith, Continuous Surface Cap Model and Riedel-Hiermaier-Thoma models, with concrete meshing based on 10, 15, and 20 mm. Six full-scale beams were tested: four of them used for the initial calibration of the numerical model and two more tests at lower scaled distances. For calibration, field data obtained employing pressure and accelerometers transducers were compared with the results derived from the numerical simulation. Damage surfaces and the shape of rupture in the beams have been used as references for comparison. Influence of the meshing on accelerations has been put in evidence and for some models the shape and size of the damage in the beams produced maximum differences around 15%. In all cases, the variations between material and mesh models are shown and discussed. 展开更多
关键词 Blast test Numerical simulation LS-DYNA concrete model Mesh effect Full-scale beams
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Analysis model for damage of reinforced bars in RC beams under contact explosion
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作者 Chaozhi Yang Zhengxiang Huang +2 位作者 Xin Jia Wei Shang Jian Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第11期104-118,共15页
The load-bearing capacity of reinforced concrete(RC) beams primarily relies on internal reinforced bars.However, limited research has been conducted on the dynamic response of these bars. To address this gap, this stu... The load-bearing capacity of reinforced concrete(RC) beams primarily relies on internal reinforced bars.However, limited research has been conducted on the dynamic response of these bars. To address this gap, this study has established an analytical model using dimensional analysis for calculating the deformation of reinforced bars within RC beams subjected to contact explosion. Comparison with experimental data reveals that the model has a relative error of 5.22%, effectively reflecting the deformation of reinforced bars. Additionally, based on this model, the study found that while concrete does influence the deformation of reinforced bars, this influence can be disregarded in comparison to the material properties of the bars themselves. The findings of this study have implications for calculating the residual load-bearing capacity of damaged RC beams, evaluating the extent of damage to RC beams after blast loading, and providing guidance for the blast-resistant design of RC structures. 展开更多
关键词 Reinforced concrete beam Contact explosion Reinforced bar Damage analysis Residual load-bearing capacity
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钢次梁-混凝土主梁插入式连接节点力学性能研究
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作者 孙晓红 陈贵鹏 +2 位作者 杨树桐 李胜林 王艳强 《建筑施工》 2025年第2期192-195,共4页
为探究钢次梁-混凝土主梁插入式连接节点的静力性能,以主次梁高度差、钢次梁上方是否布置楼板为主要试验参数,对5个插入式节点试件进行单调静力加载。试验结果表明:试件破坏受控于钢次梁插入位置主梁下部混凝土的冲切破坏;随着主次梁底... 为探究钢次梁-混凝土主梁插入式连接节点的静力性能,以主次梁高度差、钢次梁上方是否布置楼板为主要试验参数,对5个插入式节点试件进行单调静力加载。试验结果表明:试件破坏受控于钢次梁插入位置主梁下部混凝土的冲切破坏;随着主次梁底高差的增加,主梁对钢次梁的约束作用增强,试件的承载力提升;此外,有限元模拟结果表明,试件承载力整体随主次梁底高差的增大而增大,但当主次梁底高差大于256 mm时,破坏模式由主梁底部冲切破坏变为钢次梁弯曲破坏,主次梁底高差对承载力的影响明显减小。当主次梁高度差不变时,增大钢次梁插入深度或减小主梁内箍筋间距,可有效提升试件的极限承载力。 展开更多
关键词 插入式节点 钢次梁 混凝土主梁 静力性能 数值模拟
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钢-混组合桥面混凝土层横向受力的弹性地基梁比拟模型
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作者 叶华文 何建希 +2 位作者 潘威洲 周渝 邓雪峰 《哈尔滨工业大学学报》 北大核心 2025年第3期90-97,109,共9页
钢-混组合桥面板的混凝土铺装层设计参数多由工程经验确定,针对因缺乏明确的受力机制分析而容易导致其结构开裂或不经济的问题,根据正交异性钢-混组合桥面板构造特点,将混凝土铺装层横桥向受力比拟为弹性地基上的无限长梁,建立了轮载下... 钢-混组合桥面板的混凝土铺装层设计参数多由工程经验确定,针对因缺乏明确的受力机制分析而容易导致其结构开裂或不经济的问题,根据正交异性钢-混组合桥面板构造特点,将混凝土铺装层横桥向受力比拟为弹性地基上的无限长梁,建立了轮载下混凝土层横桥向效应的理论分析模型,推导了混凝土层横桥向弹性变形、受力和有效作用范围的解析式。以实际正交异性钢-混组合桥面构造为原型,设计和实施了足尺模型静载试验,还进行了空间有限元仿真分析,结果证明了弹性地基梁比拟模型的合理性。因横隔板和刚性混凝土层约束,偏载下U肋扭转变形可忽略不计;轮载横桥向有效作用范围不超过5个U肋中心距。基于有限元的参数分析表明:栓钉布置和横隔板对混凝土层横桥向受力影响很显著。在所提的混凝土铺装层设计参数取值范围内,提出的横桥向受力计算公式适用于正交异性钢混组合桥面设计。 展开更多
关键词 钢-混组合桥面 轮载作用 弹性地基梁 混凝土铺装层 横向受力
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负弯矩作用下部分充填式窄幅钢箱-UHPC组合梁刚度分析
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作者 莫时旭 柴龙杰 +2 位作者 郑艳 黄意均 檀新宁 《河南理工大学学报(自然科学版)》 北大核心 2025年第2期164-175,共12页
目的为研究负弯矩作用下部分充填式窄幅钢箱-UHPC(ultra-high performance concrete,UHPC)组合梁的抗弯性能,采用反向集中力对9根不同参数的试验梁进行静载试验。方法研究部分充填式窄幅钢箱-UHPC组合梁在反向集中力作用下的受力过程、... 目的为研究负弯矩作用下部分充填式窄幅钢箱-UHPC(ultra-high performance concrete,UHPC)组合梁的抗弯性能,采用反向集中力对9根不同参数的试验梁进行静载试验。方法研究部分充填式窄幅钢箱-UHPC组合梁在反向集中力作用下的受力过程、应变行为、刚度和抗裂性,明确各参数在提升试验梁力学性能方面的贡献程度,并将考虑界面滑移和翼板开裂因素的理论挠度与试验结果进行比较和验证。结果部分充填式窄幅钢箱-UHPC组合梁处于整体弹性阶段时刚度最高,翼板开裂后刚度略有下降,钢箱下翼缘局部受压屈服时,跨中翼板上形成多条贯通裂缝,极限承载力阶段,承载力未明显下降。与部分充填式窄幅钢箱-NC(ordinary concrete,NC)组合梁和窄幅钢箱-UHPC组合梁相比,随着钢纤维掺量、配筋率和相对充填高度增加,部分充填式窄幅钢箱-UHPC组合梁的极限承载力、正常使用和承载能力极限状态的最大刚度分别提高57%,25%,21%,裂缝宽度为0.05,0.10,0.20 mm时,对应的最大荷载分别提高155%,266%,100%。结论部分充填式窄幅钢箱-UHPC组合梁刚度大,抗裂性能好,承载力高。现行规范计算负弯矩作用下组合梁挠度过于保守,考虑负弯矩作用下组合梁滑移影响的有效惯性矩法计算试验梁挠度较为准确。 展开更多
关键词 部分充填式窄幅钢箱-UHPC组合梁 超高性能混凝土 负弯矩 极限承载力 裂缝宽度
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混凝土梁疲劳致力磁效应及数值模拟方法
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作者 金伟良 刘振东 张军 《材料导报》 北大核心 2025年第1期201-209,共9页
根据铁磁材料的力磁效应机制,分析了四种典型力磁模型的特点。通过对比受弯混凝土梁在静力加载阶段的力磁效应数值模拟结果,发现使用表征宏观磁学属性的应力-矫顽力关系具有较好的适用性。基于高应力阶段磁效应衰减机理,建立了混凝土梁... 根据铁磁材料的力磁效应机制,分析了四种典型力磁模型的特点。通过对比受弯混凝土梁在静力加载阶段的力磁效应数值模拟结果,发现使用表征宏观磁学属性的应力-矫顽力关系具有较好的适用性。基于高应力阶段磁效应衰减机理,建立了混凝土梁疲劳阶段的力磁模型,并进行了受弯混凝土梁疲劳致力磁效应的数值模拟,探究特征磁信号与疲劳寿命之间的关系。研究结果表明:修正后的力磁模型在静力加载阶段呈三阶段变化规律,与试验结果一致,且模拟误差在8%左右;疲劳阶段模拟力磁的时变曲线与试验结果变化规律相一致,误差在15%以内;建立了混凝土梁疲劳寿命与特征磁信号的映射关系式,计算结果与试验结果基本吻合,可以作为受弯混凝土梁疲劳寿命的预测模型。 展开更多
关键词 混凝土梁 疲劳损伤 磁效应 力磁模型 疲劳寿命
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往复荷载作用后钢管混凝土柱-组合梁节点耐火性能数值分析
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作者 王文达 李生强 +1 位作者 毛文婧 郑龙 《建筑科学与工程学报》 北大核心 2025年第1期1-13,共13页
为研究钢管混凝土柱-组合梁节点在往复荷载作用后的耐火性能,利用有限元软件ABAQUS建立了该节点的有限元分析模型,并与已有试验结果进行对比验证。在此基础上,分析了往复荷载作用后塑性损伤和残余变形对组合梁节点火灾下的应力和变形的... 为研究钢管混凝土柱-组合梁节点在往复荷载作用后的耐火性能,利用有限元软件ABAQUS建立了该节点的有限元分析模型,并与已有试验结果进行对比验证。在此基础上,分析了往复荷载作用后塑性损伤和残余变形对组合梁节点火灾下的应力和变形的影响,以及不同损伤程度、荷载作用水平和防火保护层厚度对节点耐火极限和破坏模态的影响。结果表明:地震预损伤对节点的耐火极限有不利影响,且随损伤程度的增加,耐火极限下降明显;重度损伤下节点的耐火极限与无损伤节点相比降低了23.5%;重度损伤的节点在火灾作用下形成塑性铰,且产生较大的耗能损伤,轻度和中度损伤下未形成明显塑性铰,耐火极限分别仅下降1.0%和3.6%;对于以梁损伤作为预损伤模式的节点,梁荷载比和防火保护层厚度是影响有地震预损伤节点耐火极限的主要因素;随柱荷载比的增大,耐火极限呈降低趋势,但整体影响不大。 展开更多
关键词 钢管混凝土柱-组合梁节点 低周往复加载 损伤程度 耐火极限
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原型构件锈蚀钢筋混凝土梁承载力计算方法
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作者 刘梅梅 应宗权 +2 位作者 李嘉民 赵娟 梁梓豪 《水运工程》 2025年第2期45-50,88,共7页
为了准确评估锈蚀钢筋混凝土梁受弯承载力,以3根原型构件锈蚀钢筋混凝土梁为研究对象,进行承载力试验及仿真分析,并提出可修正规范方法的锈蚀钢筋混凝土梁受弯承载力简化计算方法。采用该方法,可以根据现场检测得到的锈蚀钢筋混凝土梁... 为了准确评估锈蚀钢筋混凝土梁受弯承载力,以3根原型构件锈蚀钢筋混凝土梁为研究对象,进行承载力试验及仿真分析,并提出可修正规范方法的锈蚀钢筋混凝土梁受弯承载力简化计算方法。采用该方法,可以根据现场检测得到的锈蚀钢筋混凝土梁构件某一根或几根钢筋截面损失率换算得到同一截面处所有钢筋的平均截面损失率,用于计算锈蚀钢筋强度利用系数,并解决了钢筋截面损失率大于10%时承载力计算不准确的问题。 展开更多
关键词 原型构件 锈蚀钢筋混凝土梁 受弯承载力 截面损失率 损伤塑性模型 广义极值分布
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