共查询到20条相似文献，搜索用时 171 毫秒
1.
目的:提出一种稳定性好、便于张拉施工的双撑杆索穹顶结构,以解决该结构的找力分析问题,并考察其施工方法和静力性能,为工程实践提供参考依据。方法:1.通过节点平衡方程,推导出考虑结构自重时的双撑杆索穹顶结构的预应力分布计算公式;2.通过模型试验,比较采用空中组装和整体提升两种施工方法时,结构的内力和位形变化;3.进行满跨荷载和半跨荷载的加载测试,并与有限元分析结果进行了对比。结论:1.本文所得公式可以准确得到双撑杆索穹顶结构考虑自重后的实际预应力分布。2.该结构适合通过张拉外斜索施加预应力;结合整体提升的施工方法,可以显著降低施工难度,使其更适用于实际工程。3.在外荷载作用下,双撑杆索穹顶结构中脊索和内斜索的内力减小,其他斜索和环索的内力增大。 相似文献
2.
1 各章的学习要求 受弯构件正截面、斜截面承载力计算,受压构件承载力计算,钢筋混凝土梁板结构为重点内容。受弯构件与受压构件部分要求理解受力各阶段的应力分布、破坏特征及计算的基本假定,熟练掌握承载力计算。 钢筋混凝土的力学性能、结构设计方法、受拉构件承载力计算为次重点内容。 钢筋混凝土构件变形和裂缝验算、预应力混凝土的基本知识为了解内容。 相似文献
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建立了T形配钢型钢混凝土偏压构件力学性能分析的有限元模型,计算结果得到以往实验结果的验证。在此基础上,分析了不同阶段材料应力状态和各参数对偏压构件力学性能的影响。结果表明:T形配钢型钢混凝土构件在不同加载角下的性能有所不同,加载角为180°时极限承载力大于其他角度情况;混凝土抗压强度、型钢含钢率、配筋率、荷载偏心率、长细比对构件荷载-变形曲线的影响较大,随着混凝土强度、型钢含钢率、配筋率的增加,极限承载力和刚度增加;随着荷载偏心率的增加,极限承载力和刚度下降;随着构件长细比的增加,构件承载力总体呈现线性下降趋势,刚度下降明显。 相似文献
4.
王圻 《现代远程教育研究》2000,(2)
1 各章的学习要求受弯构件正截面、斜截面承载力计算,受压构件承载力计算。钢筋混凝土梁板结构为重点内容。受弯构件与受压构件部分要求理解受力各阶段的应力分布、破坏特征及计算的基本假定,熟练掌握承载力计算。钢筋混凝土的力学性能、结构设计方法、受拉构件承载力计算为次重点内容。钢筋混凝土构件变形和裂缝验算、预应力混凝土的基本知识为了解内容。2 考试的几点说明本学期本课程为闭卷考试。试题内容不超出本复习提要的范 相似文献
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采用有限元法,全过程分析了考虑长期荷载作用下时构件的应变-荷载曲线。基于有限元模型,分析了长期荷载作用下圆端形钢管混凝土柱的工作机理。结果表明:考虑长期荷载作用影响对圆端形钢管混凝土柱的内力分布、变形有较大影响,对承载力影响不大,且随着高宽比的增大,构件的峰值荷载增大,延性减小。 相似文献
6.
当压弯构件没有设置侧向支撑时,在外荷载尚未达到平面内弯曲失稳的临界荷载之前,就可能导致压弯构件发生空间的弯扭失稳,也称平面外弯扭屈曲。当构件长细比较大时,有可能在弹性阶段失稳,在长细比较小等情况下也有可能在弹塑性阶段失稳。采用如下假设进行分析:构件为弹性体;发生弯曲与扭转变形时,截面的形状不变;弯曲与扭转变形微小;构件是无缺陷的等截面直杆;在弯矩作用平面内抗弯刚度很大,屈曲前平面内的弯曲变形对弯扭屈曲的影响可以忽略。 相似文献
7.
本课程自九四级始采用滕智明、张惠英编写,中央电大出版社出版的新教材。电视课时72学时,分两学期播出。本学期完成上册的教学内容。 上册的内容主要有:1.基本理论:混凝土和钢筋的力学性能,结构设计方法。2.基本构件的承载力计算:受弯、受压、受拉、受扭构件的受力性能、计算方法和配筋构造。3.钢筋混凝土梁板结构。 本学期的重点内容为:受弯构件正截面、斜截承载力计算,受压构件承载力计算及钢筋混凝土梁板结构。次重点内容为:混凝土和钢筋的力学性能,结构设计方法,受拉构件与受扭构件的承载力计算。一般了解内容为:钢筋混凝土的构件的变形和裂缝宽度计算,预应力混凝土的基本知识。 相似文献
8.
钢管混凝土结构构件充分发挥了钢管与混凝土两种材料的特性和潜力,近年来越来越广泛地被用于工业与民用建筑、大型桥梁及地下结构等重要工程领域。借助DHR9401型落锤式冲击实验机,完成了两端固定边界条件下,两种壁厚的钢管混凝土梁的侧向撞击试验,得出以下结论：钢管混凝土构件具有良好的抗冲击作用,在构件受到突加荷载作用时,表现出了很好的延性;钢管混凝土受到侧向冲击时,材料有明显的屈服阶段;落锤的速度越高和质量越大,构件的动力响应越明显。 相似文献
9.
钢筋混凝土受扭构件计算中,薄膜元理论计算模型需要一套准确的材料本构关系方程,本文考虑了钢筋混凝土受扭构件开裂后受拉混凝土的作用,分析了其对受扭构件承载力和变形的影响.对计算模型中的受拉混凝土和钢筋的本构关系方程作了改进,并对受扭构件承载力和变形做了计算,理论结果和试验结果吻合较好. 相似文献
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11.
Design of offshore wind power foundation with multi-bucket 总被引：1，自引：0，他引：1
Three- and four-bucket offshore wind power foundations with a new form of force-transferring structure are proposed in this paper, and the integrated finite element model of foundation-soil-transition structure is established by using ABAQUS. The carrying capacity of the proposed foundations is studied under vertical load, horizontal load and bending moment. It can be seen that the vertical bearing capacity of multi-bucket foundation can be roughly estimated by the vertical bearing capacity of single-bucket; the horizontal bearing capacity of the three-bucket foundation scheme is controlled by displacement, while that of the four-bucket foundation scheme is controlled by the internal forces of soils. Moreover, the carrying capacity is provided by the overall structure formed by multi-bucket before soil failure. Compared with the conventional single-bucket foundation, there are mainly tension and pressure that are applied to the multi-bucket foundation, so that the carrying capacity of the foundation can be fully utilized. The probability of soil failure can be well reduced with the proposed multi-bucket foundation, and the stress transmission of force-transferring structure is more consistent through steel beams with variable cross-section. 相似文献
12.
根据支护结构的承载性能和大断面硐室的变形特点,分析了大断面硐室的围岩加固技术;大断面软岩硐室加固的总体思路就在碹后进行壁后注浆以改善碹体与围岩相互作用关系,发挥支护的承载能力,并利用高强锚索支护,对瑞碹体支护或锚网支护结构进行结构补偿。 相似文献
13.
为研究预应力混凝土连续箱梁桥的承载能力及实际工作状况,通过实际桥梁的静载试验,测得桥梁在各个工况下控制截面的应变、挠度随荷载增加能保持良好的线性关系,并判断实测残余变形与实测总变形比值小于0.2,同时采用桥梁专用有限元计算分析软件MIDAS/Civil建立试验跨模型,与静载试验实测数据进行对比分析,得到桥梁的应变校验系数和挠度校验系数,综合判断桥梁的承载能力能满足要求。 相似文献
14.
Bearing Capacity and Technical Advantages of Composite Bucket Foundation of Offshore Wind Turbines 总被引：1，自引：1，他引：0
Based on mechanical characteristics such as large vertical load,large horizontal load,large bending moment and complex geological conditions,a large scale composite bucket foundation (CBF) is put forward.Both the theoretical analysis and numerical simulation are employed to study the bearing capacity of CBF and the relationship between loads and ground deformation.Furthermore,monopile,high-rise pile cap,tripod and CBF designs are compared to analyze the bearing capacity and ground deformation,with a 3-MW wind generator as an example.The results indicate that CBF can effectively bear horizontal load and large bending moment resulting from upper structures and environmental load. 相似文献
15.
通过对填充墙钢框架和同尺寸纯钢框架结构的数值模拟,从两种不同形式的框架结构在单调荷载作用下的荷载——位移曲线、低周反复荷载作用下的滞回曲线、骨架曲线及刚度退化曲线,分析得知填充墙钢框架体系是一种理想的抗侧力体系,其优势表现在该结构的耗能能力、极限承载能力、延性、变形恢复能力及抗侧刚度均优于纯钢框架。 相似文献
16.
杨启斌 《福建工程学院学报》2015,(6):526-531
为研究双向简谐波荷载作用下群桩的力学性状及其受力性能,采用PLAXIS有限元软件建立相应的数值模型,分析了群桩基础在双向简谐波荷载作用下内力、位移响应情况,探究了桩周土体的动应力应变关系,进而对其在循坏水平荷载作用下的受力性能进行探讨。研究结果表明,与水平静载作用相比,桩基在循坏水平荷载作用下的承载能力有所降低;桩顶荷载-位移曲线出现“滞回圈”,基桩产生“疲劳效应”;桩周土抗力的变化使得各排桩内力分配不均匀;桩周土体的动应力应变关系呈现滞后性、非线性及累积性。 相似文献
17.
暨邦冲 《福建工程学院学报》2022,(1):53-60
在收集钢-混凝土组合梁试验研究资料的基础上,分别采用中国规范GB 50917-2013、JGJ 138-2016、欧洲规范Eurocode 4(简称EC4)及线弹性法,计算所收集试件的抗弯承载力,并与试验结果进行比较。结果表明:GB 50917-2013、JGJ 138-2016与EC4中抗弯承载力的计算方法,主要的不同在于有效宽度的取值、是否考虑滑移效应的影响以及是否计入纵向钢筋对抗弯承载力的贡献GB 50017-2017与JGJ 138-2016的计算方法得到的抗弯承载力的计算理论值与试验实测值更加接近,且数据更为稳定GB 50917-2013不仅考虑了整体栓钉布置导致的滑移效应,还考虑了纵向钢筋对承载力的贡献,所计算出的结果偏于保守线弹性法比塑性理论更为保守。由于目前的计算方法与实际情况仍有一定误差,下一步建议从有效宽度、纵向钢筋对抗弯承载力的贡献与滑移效应的角度出发,提出更适用于计算钢-混凝土组合梁抗弯承载力的方法。 相似文献
18.
The anchor stress extent of a prestress anchor cable project has a direct relation with the project safety and performance. Prestressed tensioning method is a kind of nondestructive testing method, by which a reverse stretching load is applied on the external exposure section of anchor cable under construction or in service, and then the elongation variation of stress bars is measured to determine the anchor stress. We elaborated the theory and testing mechanism of prestressed tensioning method, and systematically studied key issues during the prestressed tensioning process of anchor cable by using physical model test, including the composition of tension stress-elongation curve, the variation of anchor stress, the compensation of locked anchor stress, and the judgment of anchor stress, and verified the theory feasibility of prestressed tensioning method. A case study on slope anchor cable of one highway project was conducted to further discuss on the test method, operation procedures and judgment of prestressed tensioning method on obtaining anchor stress, and then the test data of three situations were analyzed. The result provides a theoretical basis and technical base for the application of prestressed tensioning method to the evaluation of construction quality and operation conditions of anchor cable project. 相似文献
19.
A double strut cable dome structural system was presented to improve the mechanical behaviour of a cable dome. This structure has good stability and is convenient to construct. To investigate its construction method and static performance, a structural model with a 6-m diameter was designed. From the nodal equilibrium equation, the calculation formulas for the prestress distribution with self-weight considered were deduced. Two types of construction methods, namely, assembling at high altitude and integral lifting, were adopted in the shape-forming process of the double strut cable dome, monitoring the internal force of the cable-strut components and the structural deformation. According to loading tests under full-span load and half-span load, the static behaviour of the structure was obtained and compared with the results from finite element analysis. Using the formulas deduced in this paper, the actual initial prestress considering self-weight for a double strut cable dome can be obtained accurately. This structure was suitable for tensioning the outer diagonal cables to apply prestress. Combined with the construction method for integral lifting, the difficulty and workload of the construction process can clearly be reduced, making the structure favourable for engineering application. Under an external load, the internal force of the ridge cables and inner diagonal cables decreases and the internal force of the other components increases. The results of the model tests were in good agreement with those of the finite element analysis. 相似文献
20.
苏福明 《福建工程学院学报》2007,5(6):652-656
根据某大楼2根无扩底人工挖孔桩灌注的静载试验,通过埋设在桩中不同土层位置的混凝土应变传感器在各级加载下所测得的数据,分析了桩端阻力、桩侧摩阻力的发挥规律和桩的变形规律,研究了人工挖孔桩的承载特性和荷载传递机理.试验结果表明,对嵌入软质岩有一定深度的人工挖孔桩,其桩的荷载传递性状呈现为摩擦桩的特点.根据这一特点,建议在人工挖孔桩设计前应对桩进行承载力试验,当桩端嵌入岩层一定深度时可不设计扩大头. 相似文献