采用MIDAS软件分析碳纤维加固钢筋混凝土梁

结合＂5.12＂兰成渝输油管道龙潭河桥的震后的检测与加固工程,应用桥梁结构有限元分析软件MIDAS,建立有限元分析模型,对该桥进行了粘贴碳纤维布加固设计模拟分析,从而提出了加固设计方案。为今后类似桥梁加固的研究与设计提供了有益经验。     

钢筋混凝土桥梁加固后时变可靠指标分析

在研究既有钢筋混凝土桥梁加固后时变可靠指标计算方法的基础上,以长江上某桥连续箱梁加固工程为例,应用ANSYS软件建立加固后桥梁的有限元分析模型,对影响加固后桥梁挠度的因素进行了敏感性分析,并采用响应面法对基于挠度分析的正常使用极限状态下结构的时变可靠指标进行了计算,对加固后桥梁结构剩余使用寿命进行了预测。     

某四类梁桥采用体外预应力法加固后试验分析

为了研究采用体外预应力加固后的桥梁实际工作状况,以实际工程为背景,采用Midas civil 2013三维有限元软件建立了结构计算模型,并对加固后桥梁进行了荷载试验,经过分析说明采用体外预应力加固方法可使该桥的承载能力满足要求,为今后类似情况的桥梁加固提供了参考依据。     

预应力碳纤维加固技术在某大桥中的应用

随着桥梁加固技术的发展,目前预应力碳纤维板加固技术广泛应用于桥梁结构中。本文以工程实例为背景,详细说明了预应力碳纤维板加固设计方案,并根据现行规范要求,基于桥梁博士有限元软件,对加固前后的受力情况进行了对比分析。加固后桥梁的刚度、抗裂以及承载能力明显提高,达到了设计要求,延长了桥梁的使用寿命。     

北绕阳河桥碳纤维加固技术及抗震性能分析

阜新市北绕阳河桥是一座待维修加固的险桥,结合工程实例,提出碳纤维加固方案。为验证加固效果,采用大型通用有限元分析软件ANSYS作为平台,对加固前后的"三肋拱梁"进行了静载荷作用下应力和变形的有限元分析。结果表明,经CFRP加固后可有效减小梁的挠度变形,提高其承载能力。通过对加固前后桥梁结构地震作用下的主要内力和位移响应对比分析表明,粘贴高强纤维能够有效增强结构的强度和刚度,提高该钢筋混凝土桥梁的抗震性能。     

钢架用于桥梁加固的探索与研究

以三等跨简支平台桥梁加固为例,提出钢结构拱形桁架的桥梁加固改造方法。通过有限元结构分析软件,分析钢结构在各种工况组合下结构的受力性能,保证了结构的安全可靠,满足了拱形钢架的强度、刚度和整体稳定要求,合理控制了钢架变形,满足了工程实际需要。     

复合砂浆预应力钢丝绳加固实桥的试验分析

复合砂浆预应力钢丝绳加固技术是一种新型桥梁结构加固技术。通过采用此技术加固的某T梁桥加固前后的静力荷载试验及有限元分析,对加固效果进行了分析。分析结果表明:加固后桥的主梁挠度和应变明显减小,加固措施有效地提高了梁抗弯承载力和刚度。同时,该加固技术可以在桥梁正常通车的情况下进行,值得在实际工程中推广应用。     

碳纤维加固桥梁有效性有限元分析

粘贴碳纤维布加固法因其几乎不增加原结构重量、具有良好适应性、施工简便、加固效果好、材料耐久、耐腐蚀性好等优点,在桥梁加固工程中得到广泛应用。本文依托武黄高速实体工程瓜塘小桥,利用有限元分析软件ANSYS建立实体模型,对碳纤维加固效果进行分析,通过对加固前后桥梁的各项指标进行对比分析,表明该方法能提高结构的极限承载力20%~30%。     

体外预应力在加固简支T梁桥中的应用

结合某高速公路桥梁加固工程实例,分析了桥梁病害成因,对结构进行验算分析,介绍了体外预应力加固技术在加固简支T梁结构中的运用,以期为类似加固工程的设计和施工积累经验。     

大跨径中承式拱桥悬吊桥面系加固改造技术

以主跨为165 m的中承式拱桥悬吊桥面系加固改造工程为例,通过对原桥结构缺陷和病害的分析,提出更换全桥吊杆、增设加劲纵梁的加固改造方案。根据结构特点和有限元计算分析对加固改造效果进行了验证,结果表明：增设加劲纵梁后各构件受力均满足设计要求,桥梁结构的安全储备显著提升,拱肋和加劲纵梁协同受力,提高了桥面结构的刚度。     

Lateral stiffness of steel plate shear wall systems

The accuracy of the finite element method and strip method of analysis for calculating the lateral stiffness of steel plate shear wall (SPSW) systems is assessed by making comparisons with experimental findings. Comparisons revealed that while both methods provide acceptable accuracy, they also require the generation of sophisticated computer models. In this paper, two alternative methods are developed. The first one is an approximate hand method based on the deep beam theory. The classical deep beam theory is modified in the light of parametric studies performed on restrained thin plates under pure shear and pure bending. The second one is a computer method based on the truss analogy. Stiffness predictions using the two alternative methods are found to compare well with the experimental findings. In addition, lateral stiffness predictions of the alternate methods are compared against the solutions provided using finite element and strip methods of analysis for a class of test structures. These comparisons reveal that the developed methods provide estimates with acceptable accuracy and are simpler than the traditional analysis techniques.     

Bending analysis of folded plates by the FSDT meshless method

In this paper, a meshfree Galerkin method that is based on the first-order shear deformation theory (FSDT) will be introduced to analyse the elastic bending problem of stiffened and un-stiffened folded plates under different loadings and boundary conditions. Folded plates are regarded as assemblies of plates that lie in different planes. The stiffness matrices of the plates are given by the meshfree method. Employing the element concept, which is borrowed from the finite element method, and treating every plate as a big element, the global stiffness matrix of the whole folded plate is obtained by superposing the stiffness matrices of the plates. This is about the same for the analysis of stiffened folded plates. They are considered as assemblies of stiffened plates. The stiffness matrices of the stiffened plates are also given by the meshfree method. Superior to the finite element methods, no mesh is required in determining the stiffness matrices for the plates and the stiffened plates in this paper, which means time-consuming and accuracy-suffering remeshing is entirely avoided for problems such as large deformation or crack propagation in folded plates or stiffener position changes of stiffened folded plates. To demonstrate the accuracy and convergence of the method, several numerical examples are calculated by it and the finite element commercial software ANSYS. Good agreement is observed between the two sets of results.     

体外预应力效应的有限元模拟方法

对体外预应力钢索的传力特点进行了研究,推导了体外索单元刚度矩阵在桥梁有限元分析中的转换公式,从而得出两端带刚臂体外索单元的刚度矩阵,实现了体外预应力效应的有限元模拟.     

钢筋混凝土结构重力二阶效应分析

介绍了P-Δ效应分析中常见的4种基本方法:基于几何刚度的有限元方法、基于等效水平力的有限元迭代方法、折减弹性抗弯刚度的有限元法以及结构位移和构件内力增大系数法,并对各种方法的特点作了简要分析。对"结构在考虑P-Δ效应后其自振周期发生变化"的情况进行了讨论,并指出其合理性。最后通过算例,研究了P-Δ效应在不同高度的钢筋混凝土高层建筑的总体结构反应中所占的可能的比例,以及考虑P-Δ效应时地震作用和风荷载引起的层间位移的变化规律。     

基于ERA算法的结构损伤识别及试验研究

针对多孔砖砌体结构,分别进行了理论计算、有限元分析及其基于特征值实现法（ERA）的模态实验分析,通过对比表明3种方法分析的结果较为吻合,说明了识别的结果的正确性。根据识别出的频率,得出了损伤前后的变化规律,说明随着墙体的开裂,刚度迅速下降,极限荷载以后刚度衰减趋于平缓,表明损伤识别分析结果与多孔砖砌体压剪实验结果一致。     

装配式预应力鱼腹式钢支撑系统的刚度研究

在采用弹性支点法进行支挡结构计算时,需用到支撑结构的弹性支点刚度,而装配式预应力鱼腹式钢支撑系统因其特殊性,当前尚无方便有效的公式用于计算其系统刚度。文章引入鱼腹梁等效平均刚度的概念,推导装配式预应力鱼腹式钢支撑系统施加预应力前后刚度的简化表达式,并采用有限元软件进行验证。同时以厦门市钻石大厦基坑项目实际工程为背景,将三维有限元高精度数值模拟结果分别与现场监测数据和理论推导结果进行对比分析,一方面,有限元结果与现场监测数据的土体深层水平位移变化趋势总体上吻合,表明有限元可较为准确地模拟基坑实际的发展规律;另一方面,有限元分析得出的支撑系统刚度与理论推导结果总体上相差不大,表明文章所推导装配式预应力鱼腹式钢支撑系统刚度的简化公式较为准确,可供相关设计人员适用或参考。     

钢板剪力墙系统的侧向刚度研究

通过与试验结果进行对比,论证了有限元方法和条法在分析钢板剪力墙系统侧向刚度时的准确性。对比结果显示:对于准确的计算模型,两种方法都是准确的。本文交替采用两种方法。第一种是基于深梁理论的近似手算法。基于纯剪和纯弯作用下约束薄板的参数研究对经典深梁理论进行了修订。第二种是基于桁架模拟法的计算方法。运用两种方法预测的刚度,与试验对比结果较好。此外,将交替方法预测的侧向刚度,与一系列试验结构的有限元法和条法计算结果进行对比。对比结果显示:本文提出的预测方法是准确的,而且比传统的分析方法更为简便。     

Improved analytic method for outrigger structures considering floor stiffness

Current analytical models for outrigger structures in super high-rise buildings tend to oversimplify by not considering the stiffness of individual floors. This paper introduces a more refined calculation model, based on the substructure method, which takes floor stiffness into account. To verify our proposed approach, we derived a mathematical algorithm and developed a finite element model using ANSYS. When compared to traditional methods that only account for outrigger stiffness, our model, which incorporates both outrigger and floor stiffness, provides improved accuracy in calculating vertex displacement. It also suggests an upward shift in the optimal position for the outrigger and bolsters the overall building's lateral stiffness. To further our analysis, we introduced an equivalent stiffness calculation formula, using the Bayesian parameter estimation method. When applied to dynamic analysis, this formula aligns closely with the results from the finite element simulations. Furthermore, the suggested algorithm for determining the best position for the outrigger is consistent with theoretical calculations. By considering the contribution of regular floors to the overall structure, we found that the fitted equivalent core tube stiffness offers a reliable reflection of structural stiffness. Lastly, when this equivalent stiffness was applied to a dynamic analysis based on Rayleigh's energy method, there was a noticeable reduction in computational effort. This yields not only more efficient calculations but also precise results, rendering it particularly valuable during the initial design phases of high-rise buildings.     

冷弯型钢骨架墙体抗侧移刚度计算方法研究

为了获得冷弯型钢骨架墙体抗侧移刚度实用计算公式,将墙体墙面板等效为拉压斜杆,并基于其他一些基本假定提出了冷弯型钢骨架墙体抗侧移刚度简化计算模型,在弹性分析的基础上得到了墙体抗侧移刚度理论计算公式,并结合试验数据和有限元分析结果进行了弹塑性修正,得到单面覆石膏板墙体、单面覆OSB板墙体、单面覆带肋钢板墙体在水平风荷载、水平多遇、水平罕遇地震作用下抗侧移刚度实用计算公式,墙体抗侧移刚度实用计算公式计算结果与试验、有限元分析结果吻合较好。同时,提供了冷弯型钢骨架墙体抗侧移刚度实用计算公式应用算例,以供设计参考。     

高层装配式斜支撑钢框架结构设计研究

针对远大S30工程的高层装配式斜支撑钢框架结构体系,分别采用振型分解反应谱法和线性时程分析法对整体结构进行有限元分析,得到了结构在多遇地震作用下的内力和位移响应。进行了结构整体的弹性设计,总结了该结构体系的设计方法。按规范对柱与柱座法兰连接的承载力进行了计算,并通过有限元分析和试验研究进行了节点强度和刚度的分析与验证。对梁柱节点进行了试验,研究其刚度变化规律,提出了采用弹簧单元在整体结构中建立节点简化分析模型的方法。研究结果表明：该体系中轻型钢楼梯对整体刚度的影响可以忽略,计算时可不建模分析;结构抗震性能满足现行规范要求,结构侧向变形曲线介于框架结构和剪力墙结构变形曲线之间;斜支撑降低了节点区的应力,增大了结构体系刚度,起到了减小柱计算长度、增强梁柱节点和柱与柱座连接的作用;柱与柱座法兰连接设计既满足设计强度要求,又实现了柱的刚性连接,保证了柱承载力和刚度的连续性。