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1.
新型土坯墙体房屋抗震性能试验研究 总被引：2，自引：0，他引：2
提出了一种新型土坯墙房屋,对新型土坯墙房屋承重墙体的受力及抗震性能进行试验研究。设计三片新型土坯墙试件,研究土坯墙体在竖向荷载和反复水平荷载作用下的破坏过程、破坏形态、滞回曲线和骨架曲线特征以及墙体水平承载力和变形能力等,同时,研究新型构造措施对土坯墙抗震性能的作用。试验表明：新型土坯墙体的破坏模式与配筋混凝土小型空心砌块相似,土坯墙体具有良好的承载力和变形能力。新型构造措施对墙体整体抗震性能作用明显,其连接构造至关重要。与计算结果比较得出,在建筑抗震概念设计原则指导下,抗震设防7度区采用新型土坯墙建造二层房屋具有可行性。 相似文献
2.
为准确分析单箱双室组合箱梁的剪力滞效应,考虑钢混凝土的界面滑移效应和钢腹板的剪切变形,针对顶底板和翼板定义不同的剪力滞翘曲位移函数,基于能量变分法推导出单箱双室组合箱梁剪滞效应的控制微分方程及其闭合解。以单箱双室组合箱梁算例为基础,利用该方法分析其剪力滞效应的规律,结果表明：在同时考虑滑移和剪切变形时,组合箱梁的挠度比初等梁理论解大,且其挠度随界面滑移刚度的增大而减小;组合箱梁在均布荷载作用下,滑移量与荷载值近似成正比关系;在相同条件下,钢箱梁底板的剪力滞效应较混凝土顶板显著。 相似文献
3.
在梁侧或梁底用波形齿横向张拉CFRP片材并锚固的体外预应力加固混凝土结构技术,对3根完全相同的7 m跨T形截面梁进行加固：其中2根梁侧面加固;1根梁底部加固。试验表明：多点锚固体外无粘结CFRP预应力可以依据构件的弯矩来调整各段的加固量从而更有效的利用CFRP材料的高强性能;梁底与梁侧加固对提高构件的抗弯刚度差别不大;波形齿能彻底解决预应力CFRP片材的锚固问题。以该3根加固梁的试验结果为基础,提出了梁体极限状态下塑性绞区长度的体外无粘结预应力碳纤维加固受弯构件的抗弯承载力公式,以及考虑二次效应的有效惯性矩法的挠曲变形的计算公式,通过与试验值的对比分析可知,所提出的方法可供设计参考使用。 相似文献
4.
钢筋混凝土无腹筋细长梁剪切破坏机理模型研究综述 总被引：1，自引：0，他引：1
根据现有关于钢筋混凝土无腹筋细长梁剪切破坏机理问题的研究成果,介绍了基于修正压力场理论的抗剪模型、临界剪切裂缝理论、塑性理论、压力路径理论、劈裂破坏理论和基于截面应变分析的抗剪模型的基本假设、核心观点及受剪承载力计算方法,并给出总结、归纳及评析;另一方面,利用相关试验数据和ACI-DAfStb无腹筋细长梁剪切破坏数据库,分别对不同理论模型的受剪承载力计算公式进行了设计参数的影响评估和统计评估;并展望了无腹筋细长梁剪切破坏机理研究的发展方向。研究结果表明：不同理论模型的部分假设缺少直接的试验依据支持,梁腹混凝土的受拉（劈裂）或受剪（骨料咬合）以及受压区混凝土对抵抗剪力的贡献成为抗剪机制的主要分歧;不同受剪承载力计算公式对不同影响因素的考虑方式的合理性和计算结果的准确度均有待进一步提高。后续深入研究应综合考虑剪切破坏问题的随机性和物理属性,利用先进测试技术、应力演化分析方法,进一步揭示剪切破坏机理。 相似文献
5.
RC加气混凝土砌块组合墙加固框架抗震性能试验研究 总被引：1，自引：0，他引：1
RC加气混凝土砌块组合墙（简称组合墙）是由混凝土梁柱网格与加气混凝土砌块组合形成的一种轻型网格式抗震墙,可用于框架结构的抗震加固。笔者进行了1/2比例空框架试件、组合墙试件和组合墙加固框架试件的低周反复荷载试验,分析了各试件的主要破坏过程,对比了组合墙加固框架前后试件承载能力、刚度等抗震性能变化。试验结果及分析表明：组合墙加固框架后承载力、抗侧刚度有较大幅度提高,中大震及大震阶段其承载力、等效刚度约为空框架和组合墙单独受力之和的0.9倍,两者具有良好的协同工作性能;加固试件的破坏过程基本上遵循填充砌块混凝土框格外框架的破坏顺序,能够发挥组合墙多重抗震防线的特点,采用RC加气混凝土砌块组合墙加固框架是一种较为经济实用的加固方法。 相似文献
6.
输电钢管塔空间KK型管板连接节点极限承载力 总被引：1，自引：0，他引：1
空间KK型管板连接节点作为输电钢管塔中最主要的节点型式,其安全性是整个塔架结构安全的重要保证。相比较于平面K型节点,在考虑实际结构中节点空间效应后的KK型节点的受力性能更为复杂。在平面K型管板节点的试验研究基础上,对两类空间KK型管板节点展开参数化分析,重点讨论了节点几何尺寸参数和主管轴压应力比等因素对节点极限承载力的影响变化规律。结合大量有限元参数分析所得计算结果,并综合考虑各种因素对节点极限承载力的影响,提出了空间KK型管板连接节点在主管管壁局部屈曲破坏模式下的极限承载力建议计算方法。 相似文献
7.
Y形偏心支撑高强钢框架结构抗震性能 总被引：3，自引：1，他引：2
在Y形偏心支撑高强钢框架结构抗震性振动台试验的基础上,建立了试验试件的有限元模型,并验证了分析的正确性。设计了一个9层的Y形偏心支撑高强钢框架结构,以耗能梁段长度、耗能梁段腹板高厚比、高跨比为参数,对9层结构进行了非线性动力时程分析,研究了以上参数对结构抗震性能的影响。研究结果表明,改变耗能梁段长度、高跨比对结构层间侧移、耗能梁段性能、框架柱弯矩、耗能能力均有不同程度的影响,对框架柱轴力、基底剪力无显著影响;改变耗能梁段腹板高厚比对结构耗能能力有影响,对结构层间侧移、耗能梁段性能、框架柱受力、基底剪力无显著影响,并给出了相关设计建议。 相似文献
8.
采用非线性有限元分析程序ABAQUS对无粘结体外预应力CFRP片材加固简支钢筋混凝土T形梁后进行数值模拟,该模拟梁共4根分别为3根梁侧对称加固,1根为梁底加固均为四点波形齿锚固预应力CFRP带。对比结果显示,数据模拟与试验结果在构件屈服以前的承载力、变形以及极限承载力吻合程度较好,构件屈服以后的变形差别较大,因此,可在一定程度上有效替代试验分析方法。依据吻合程度最好的TL3参数设计了“两点锚固”和“四点锚固”的模型进行模拟分析。通过对锚固点数及加固量改变的对比分析可知,依据加固构件的弯矩改变各段加固量及布置锚固点数的方法既可以保证加固效果不降低,又可以节约CFRP材料。 相似文献
9.
基于等效原则、相似理论,考虑三维地震动作用下振动台试验中原型结构隔震层的简化,并对模型结构隔震层进行系统研究。针对不同高宽比隔震结构,提出完全等效简化方法和部分等效简化方法,包括隔震垫等效、模型支座参数及坐标确定、相似关系确定等。利用不同高宽比隔震结构振动台试验,结合有限元数值模拟,进行方法验证。理论推导与数值模拟证明简化方法具有良好的准确性,且在误差允许范围内,简化后的隔震层所获得的加速度、速度、位移等动力特性与简化前相同,可以用于振动台试验模型设计。 相似文献
10.
表层嵌贴预应力FRP板条加固钢筋混凝土结构技术可充分发挥FRP材料强度,且不需设置永久锚具,具有较大的潜力。以试验得到的嵌贴FRP混凝土粘结滑移关系为基础,建立了嵌贴预应力CFRP板条与混凝土的粘结应力微分方程,并根据边界条件推导了方程的解析解,得到了嵌贴预应力CFRP板条放张后界面粘结应力、CFRP拉伸应力的分析模型。与试验结果的比较表明,该模型得出的界面粘结应力及CFRP拉伸应力与试验结果吻合较好。在此基础上,考虑放张后CFRP混凝土界面不出现剥离的条件,分析了粘结界面能抵抗的最大容许预应力。 相似文献
11.
Steel concrete composite slim floors with the steel beam encased in concrete floor slabs have many advantages, including low structural height, high fire resistance and rapid construction times. These features make such floors a promising for use in multi storey steel buildings. We established a 3D finite element model of a monolithic composite slim floor using the ANSYS software package. We analyzed the loading capacity, deformation behavior, natural vibration frequency, the influence of reinforcement, and the concrete in the floor rib under a uniformly distributed vertical load. We calculated the effective width of mid girder and secondary beams. The following conclusions can be drawn from the analysis results: First, monolithic composite slim floors possess high loading capacity for common buildings. Second, the concrete rib and reinforcement ratio in the rib have significant effects on floor loading capacity. Third, calculation of effective primary beam width should be based on analysis of monolithic floors rather than single beams. 相似文献
12.
Because high material strength and composite load-bearing are emphasized in constructing members for high-rise steel frame structures, in a composite connection, steel strength has a dramatic influence on both the bearing performance and the composite action of the concrete slab. Based on a finite element analysis, we discuss the composite effect and the connection breaking mode, focusing on the performance change of the composite effect in adopting high strength steel. It can be found from the results that, along with the improvement of the steel strength, the elastic and plastic ultimate strength of the composite connection will increase, the ductility will decrease to a certain extent, and the composite effect of the concrete slab will diminish. The collapse of the concrete in a positive moment side contacting the column flange is viewed as the limiting state of the connection. 相似文献
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14.
The experimental results of reinforced concrete sandwich beam column joints were studied intensively and finite element method simulation of such joints were performed for the sake of design method.Basic design criterion and computation contents were provided according to failure mode of specimens and other experimental results.And the limits of parameters were proposed based on the analysis of seismic behavior influence factors and comparison of traditional joints and sandwich joints.Hence, formulas of load resistant capacity were acquired by the results of load resistant capacity of specimens and nonlinear finite element method simulation.It is found that three measures should be taken for sandwich joints in order to reach demanded ductility and load resistant capability.Firstly, several parameters should be limited, including shear compression ratio, axial load ratio, ratio of beam concrete strength to column concrete strength, and minimal amount of transverse reinforcement of joint.Secondly, shear load resistant capacity and axial compressive load resistant capacity should be computed to ensure load resistant capability of joint, and essential strengthen measures could be applied if necessary.Thirdly, appropriate construction details should be taken to avoid reducing of beam bar anchorage capacity. 相似文献
15.
Experimental Analysis on the Mechanical Properties of Concrete Composite Slabs with Precast Prestressed Rectangular Rib Panels 总被引：1，自引：0，他引：1
For the convenience of industrialized production and site operation,specification design of PPCRP (precast prestressed concrete ribbed panels) is discussed. In order to obtain ultimate bearing capacity,bending rigidity and crack resistance,four PPCRP with two types of spans are studied,and the results show that PPCRP can satisfy the requirements of bearing capacity in construction phase and can serve as stay-in place formwork. To verify the mechanical property,shear behavior on contact interface of composite member and moment redistribution factor of continuous composite member,two single-span composite members and one two-span continuous composite member are studied. It is indicated that computational method for bearing capacity of composite member can be the same as cast-in-situ concrete slab. Besides,section strain analysis for composite member in two-loading is conducted,which suggests that thickness of bottom board can be used as calculated height with the consideration of two-loading. 相似文献
16.
Spatial Calculation Methods of Three Main Trusses Continuous Plate truss Composite Bridge 总被引：2，自引：0，他引：2
According to the structural features of three main trusses continuous plate truss composite bridge, two composite beam methods are presented by constructing the displacement mode of composite beam elements and deriving the stiffness matrix of composite beam elements. The characteristic of composite beam method one is that the bridge slab is taken as the top flange of the chord of main truss and combined with the chord of main truss to form a steel concrete composite beam; the characteristic of composite beam method two is that the bridge slab is taken as the top flange of longitudinal and traverse beam and form a steel concrete composite beam with longitudinal and traverse beams. And as for the conventional plate beam composite method, the slab is characterized by forming bridge slab system with continuous isotropic sheets and longitudinal and traverse beams to bear load. Also, the comparison between theoretical results and experimental ones verifies the effectiveness of the above three methods. 相似文献
17.
With regard to the long span continuous composite beams, the early composite shear stud strength at the joint surface between the steel girder and concrete slab at different concrete ages should be considered while the concrete slabs are casted by phases in construction stage. In this study, the push-out test of stud shear connectors were conduced at different concrete ages. Meanwhile, the change law of the ultimate shear strength, ultimate slip deformation, design shear strength, and shear stiffness of the stud shear connectors with concrete ages were analyzed, and the corresponding time-dependent calculation equations were presented. The results include that the main failure modes of stud shear connectors are the concrete slab splitting failure before 3-days concrete age. The load-slip laws of stud shear connectors at different concrete ages are basically the same, however, the shear strength and stiffness all increase with the concrete ages prolonging, and the increase degree is faster at early ages, but slower at later ages, which indicates that the early composite shear stud strength at the joint surface of composite beams should not be neglected. 相似文献
18.
Deng Chaorong Niu Shaoren 《保鲜与加工》1989,(4)
In this Paper,multistoryed buildings of brick and RC floor slab construction are put up on frame beam of 12. 6 m partially prestressed concrete.A test and analysis is carried out on site.It provides a new scheme for multisto-reyed and highrise buildings with beam of transitive force and transfer floor. 相似文献
19.
Theoretical and Experimental Analysis of Bending Behavior of Composite Beam with Notched Web 总被引：2，自引：0，他引：2
A new kind of steel-concrete composite beam with notched web is proposed, and the bend and shear behaviors of this composite beam are investigated. First of all, the constitution, bearing characteristics and merits of the steel-concrete composite beam with notched web are introduced; then, a group of formulas about the bending capacity, slip between the steel beam and the concrete flange, and the deflection are introduced; after that, the bending behavior, slip effect and bearing characteristic of the steel-concrete composite beam with notched web are studied on 4 specimens, which are tested by applying two concreted vertical loads on the top of concrete flange. And the finite element model is adopted to analyze the results of the 4 specimens; finally, the reliabilities of the formulas are verified by comparing the results of theoretical formulas, the results of tests and that of finite element analysis. Study shows that the bend behavior and shear behavior are fine, and the popularization of this new kind of composite beam which can be broadly used in building engineering will save the consumption of steel. 相似文献
20.
During the pre - stressing of the unbonded prestressed concrete wide flat beam - waffle slab system, the displacements and strains of slab and the prestressed concrete beams were site - measured and the results were analyzed. The prestressing construction was simulated by finite element program. The prestressing efficiency of the unbonded prestressed concrete wide flat beam - waffle slab system was discussed. It indicates that the prestressing efficiency was affected by the in -plane stiffness of slab. 相似文献