共查询到20条相似文献，搜索用时 421 毫秒
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采用SAP2000有限元程序对装配式钢结构进行静力荷载分析、模态分析和两个方向的地震荷载分析,讨论结构在多条地震波作用下的动力位移及内力响应。结果表明,该结构在静力荷载和地震荷载作用下,内力和位移均能满足规范要求。其计算结果对于确保装配式钢结构的抗震安全性具有重要意义,对装配式钢结构的抗震设计有一定的参考价值。 相似文献
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随着钢结构的发展,钢管搭接节点应用越来越广泛.钢结构中节点受力最复杂,目前对平面K型钢管搭接节点的静力研究有很好的基础.但是在低周往复荷载下节点滞回性能的分析还比较少.采用有限元法对平面K型圆钢管搭接节点在弦杆轴向荷载作用下节点的承载力进行研究,对比分析不同几何参数与节点焊接形式下的极限承载力和破坏形式. 相似文献
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为深入研究预制拼装结构的人致振动特性,采用限制结构加速度响应的方法,对某预制拼装人行斜拉天桥的舒适度进行评价.通过在控制点布设加速度传感器,获得结构在环境激励下的振型、自振频率及阻尼比;根据桥面拼接的弹性连接结构特性,确定相邻节段间的弹性连接刚度;参照国内外相关规范,建立行人和车辆通行荷载分析模型,获得各种荷载工况下的峰值加速度,分析人行天桥的舒适度.结果表明：结构的自振频率和峰值加速度与实测值吻合良好,从而验证了有限元分析模型的有效性;考虑预制拼装对结构刚度的折减可以更真实地反应结构的振动特性,预制拼装结构的舒适度评价指标与整体式结构一致;人群质量对该结构振动频率的影响较小,可以不考虑人群荷载与车辆通行荷载的耦合作用;车辆通行荷载对结构的舒适度产生一定程度的影响. 相似文献
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魏瑞演 《福建工程学院学报》2002,(1)
从基本的钢结构材料在高温下的力学性能着手 ,进行高温条件下钢结构材料的性能试验 ,建立高温下钢材的屈服强度、极限强度、弹性模量和极限应变随温度变化的力学模型 ,为高温 (火灾 )条件下钢结构的结构分析提供依据。 相似文献
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弹性荷载法用于作结构的线位移图,比之共轭梁法的应用范围要广。对于具体的结构,若导出弹性荷载的实用计算公式,就更便于应用。本文仅对方法的基本理论进行如下一些讨论。一、论证方法若给出链条(图1a)和链条位移图(图1b)以及虚梁(图2a)和虚梁弯矩图(图2b)的完整图形,由此出发去论证,可以对弹性荷载法的实质和弹性荷载的计算更明确地加以说明。 相似文献
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周家泽 《武汉职业技术学院学报》2003,2(2):43-45
讨论了随机荷载特性与结构弹塑性极限分析的基本假设，基于机动法和静力法，对矩形截面梁的随机弹塑性极限分析进行了研究，其结果对结构随机优化设计具有重要意义。 相似文献
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为准确计算正三角形广告牌面板上的风荷载,对比了《户外广告设施钢结构技术规程》（CECS148：2003）和《建筑结构荷载规范》（GB50009-2012）中关于三面广告牌面板风载体型系数的取值和计算方法,并与正三角形三面广告牌的仿真分析结果进行比较,发现在不同的风向角下《户外广告设施钢结构技术规程》（CECS148：2003）规定的风载体型系数最小,而仿真分析得到的风荷载压力系数最大。为保证结构的安全,基于仿真分析的结果,给出了三面广告牌风载体型系数建议值;同时考虑到风荷载的非平稳性和随机性,引入风荷载的偏心距系数,为落地式三面广告牌的设计提供参考。 相似文献
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实际工程中的钢结构装配式施工,对施工荷载的分析和计算,所考虑的荷载形式较大部分是由各参与单位根据以往施工经验所归纳总结得出的荷载简化.然而,由于材料性能和施工荷载简化的形式与实际大不相符,实际工程中的钢结构预加应力的装配方式成为了较为常见的现象.对于带斜支撑的钢框架结构的装配式施工,如果对预加应力装配方式与作用在结构上的荷载形式与大小等方面考虑不足时,极易形成偏离实际的结构应力分布状态.本文中通过优先单元法建立了装配式钢框架结构的施工节点分析模型,控制框架柱竖向位移的同时,对斜支撑的施工作业顺序加以优化,最终得到了与设计的理想状态相近的结构受力状态,并实现了斜支撑的后期更换,保障了结构安全与耐久性,为日后类似工程的开展提供了借鉴依据. 相似文献
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Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks
In this paper, numerical method is used to study the strain rate effect on masonry materials. A typical unit of masonry is selected to serve as a representative volume element (RVE). Numerical model of RVE is established with detailed distinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results. 相似文献
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Ultra high toughness cementitious composite (UHTCC) usually shows strain hardening and multiple cracking under static tension loads. In practice, structures could be exposed to high strain rates during an earthquake. Whether UHTCC can maintain its unique properties and provide high structural performance under seismic loading rates largely determines whether it can successfully fulfil its intended function. To determine the rate dependence of UHTCC, uniaxial tensile tests with strain rates ranging from 4×10?6 s?1 to 1×10?1 s?1 were conducted with thin plates. The experimental results showed that UHTCC had significant strain hardening and excellent multiple cracking properties under all the rates tested. The ultimate tensile strain lay in the range of 3.7% to 4.1% and was almost immune to the change in strain rates. The rate of 1×10?3 s?1 seemed to be a threshold for dynamic increase effects of the first crack tensile strength, elastic modulus, ultimate tensile strength, and energy absorption capability. When the strain rate was higher than the threshold, the dynamic increase effects became more pronounced. The energy absorption capability was much higher than that of concrete, and the average ultimate crack widths were controlled below 0.1 mm under all rates. Several fitting formulas were obtained based on the experimental results. 相似文献
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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
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For reinforced concrete structures located along the seaside, the penetration of chloride ions into concrete may be a threat to the durability of the structures. Experimental investigations were carried out to study the effect of chloride content on the bond behavior between concrete and fiber reinforced polymer (FRP) plates. Direct shear tests were conducted on the FRP strengthened concrete members. Before testing, the specimens were immersed in NaCl solutions with concentrations ranging from 3%—15% for different time (0—120 d). Then, the specimens were dried and tested to obtain the initial and ultimate debonding loads, together with strain distributions along the FRP plates of different load values. The correlations between chloride content and debonding parameters are established. Test results show that the debonding parameters are closely related to the immersing time rather than the chloride content of the solution. 相似文献
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In this study, the effect of steel fibers coated with chemically reactive enamel (CRE) on the system response of concrete structures with reinforcing bars has been investigated for the first time. In particular, the ultimate strength, ductility, and failure mechanism of 24 reinforced concrete slabs were experimentally characterized under static and blast loads. CRE coating applied on steel bars reduced the crater area of slabs under blast loads by up to 20%; it slightly increased the strength of slabs and significantly reduced the strength degradation of slabs when increasingly deflected under static loads, making the slabs more ductile. CRE coating applied on steel fibers increased the strength of slabs by up to 16% under static loads. The influence of CRE coating applied on both steel fibers and bars may be taken into account by introducing a coating factor in the range of 0.57<β<1.0 in the American Concrete Institute (ACI) development length equation. 相似文献
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Probabilistic analysis of linear elastic cracked structures 总被引：1，自引：0，他引：1
AKRAMIN M.R.M ALSHOAIBI Abdulnaser HADI M.S.A. ARIFFIN A.K. MOHAMED N.A.N. 《浙江大学学报(A卷英文版)》2007,8(11):1795-1799
This paper presents a probabilistic methodology for linear fracture mechanics analysis of cracked structures. The main focus is on probabilistic aspect related to the nature of crack in material. The methodology involves finite element analysis; sta- tistical models for uncertainty in material properties, crack size, fracture toughness and loads; and standard reliability methods for evaluating probabilistic characteristics of linear elastic fracture parameter. The uncertainty in the crack size can have a significant effect on the probability of failure, particularly when the crack size has a large coefficient of variation. Numerical example is presented to show that probabilistic methodology based on Monte Carlo simulation provides accurate estimates of failure prob- ability for use in linear elastic fracture mechanics. 相似文献
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A numerical investigation of thin-walled complex section steel columns with intermediate stiffeners was performed using finite
element analysis. An accurate and reliable finite element model was developed and verified against test results. Verification
indicates that the model could predict the ultimate strengths and failure modes of the tested columns with reasonable accuracy.
Therefore, the developed model was used for the parametric study. In addition, the effect of geometric imperfection on column
ultimate strength and the effect of boundary conditions on the elastic distortional buckling of complex section columns were
investigated. An equation for the elastic distortional buckling load of fixed-ended columns having different column lengths
was proposed. The elastic distortional buckling load obtained from the proposed equation was used in the direct strength method
to calculate the column ultimate strength. Generally, it is shown that the proposed design equation conservatively predicted
the ultimate strengths of complex section columns with different column lengths. 相似文献
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The National Swimming Center built for the 2008Beijing Olympic Games applies the polyhedron spatialframe structure, which is based on the foam physicstheory[1]. Its simple geometry is a square box of 170m×170 m×29 m. It can hold 17 000 people, theroof o… 相似文献
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Analysis of structural response under blast loads using the coupled SPH-FEM approach 总被引：3，自引：0，他引：3
A numerical model using the coupled smoothed panicle hydrodynamics-finite element method （SPH-FEM） approach is presented for analysis of structures under blast loads. The analyses on two numerical cases, one for free field explosive and the other for structural response under blast loads, are performed to model the whole processes from the propagation of the pressure wave to the response of structures. Based on the simulation, it is concluded that this model can be used for reasonably accurate explosive analysis of structures. The resulting information would be valuable for protecting structures under blast loads. 相似文献
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纸筒作为一种轻质材料,具有绿色环保、运输方便等优点,在临建结构中具有良好的应用前景。该文通过力学试验,研究了在受压和受拉荷载下不同几何参数对纸筒构件关键力学性能的影响;明确了纸筒构件的抗压、抗拉破坏形态,给出了极限强度及峰值应变的数值区间;通过建立有限元模型,对试验进行了补充验证,进一步明确纸筒构件的受力机理,并分析了参数对纸筒构件关键力学性能的影响;最后提出一种可实现绿色生产的空间桁架纸筒结构,这种结构应用了3D节点打印技术。研究结果可为纸筒结构的实际应用提供数据支持。 相似文献