应用于结构动力反应分析方法的对比研究

对底部剪力墙、振型分解法和时程分解法三种分析方法进行了介绍，通过这三种分析方法在假设条件、计算原理、特点、应用范围上进行了对比分析，得出相应结论，以达到最好的效果。     

钢筋混凝土单向梁板子结构抗连续倒塌试验研究

梁和板组成的楼盖系统是框架结构的主要抗连续倒塌构件。为了分析各类结构参数对钢筋混凝土楼盖系统抗连续倒塌性能的影响,该文首先根据《混凝土结构设计规范》GB 50010—2010设计制作了8个钢筋混凝土单向梁板子结构缩尺试件,这些试件具有不同的截面尺寸和配筋率。然后通过竖向加载试验研究这些试件在中柱破坏后的材料变形/损伤和抗连续倒塌承载力。试验结果表明：带楼板的子结构试件的承载能力明显高于相同截面的梁试件的承载能力;试件在梁机制阶段的承载能力主要由截面尺寸和钢筋面积所决定,而悬链线机制阶段的承载能力主要由截面中连续钢筋面积所决定;楼板的宽度、厚度和板内配筋以及梁高对梁机制下的承载力有较大的提高,其中板宽在大于一定值后影响变得不显著;只有楼板宽度和楼板配筋率对悬链线机制下的承载力有显著影响;梁内抗震配筋对缩尺试件在两个阶段的抗连续倒塌承载力影响都不大。     

结构可靠度分析的全局响应面法研究

对功能函数不能明确表达的可靠度分析问题,常采用响应面法。本文提出把响应面区分为局部响应面和全局响应面。常用的二次多项式响应面及常规的神经网络响应面均属于局部响应面,其仅在验算点附近(±σ)处与真实极限状态曲面符合较好。本文提出的全局神经网络及模糊神经网络响应面、改进全局神经网络及模糊神经网络响应面则属于全局响应面,其在全局范围均与真实极限状态曲面符合良好,故其对全局有较好预测效果。文中对以上各种响应面法计算效果及其对全局预测效果通过算例进行了对比分析,其中改进全局神经网络及模糊神经网络响应面法计算精度较好,进行有限元分析次数最少,该方法用于大型复杂结构的可靠度分析,可相应提高工作效率和解题质量。     

A comparative study on different analysis approaches for estimating the axial loads on columns and structural walls at tall buildings

Estimating axial loads on columns and structural walls at tall buildings is a complicated task because time‐dependent deformations of concrete and the way the building is constructed affect the way the gravity loads are carried by them. The accurate computation of axial loads is crucial for determining the size and strengths of columns and structural walls. This study investigates several analysis approaches commonly used during the design of such buildings. Construction sequences, time‐dependent deformations and longitudinal reinforcement were considered, and their influences on results were discussed. A simplified model of an actual 37‐story building was used as a case study. The results indicated that the column and wall axial load might vary up to 45% depending on the type of analysis and effects that were considered. Copyright © 2011 John Wiley & Sons, Ltd.     

膨胀型钢结构防火防腐涂料的研究

分析了钢结构的腐蚀过程和在火灾中的行为,提出了膨胀型钢结构防火防腐涂料配方设计的依据、原则和涂料的基本组成,为膨胀型钢结构防火防腐涂料的研发提供了参考依据。     

钢结构防火措施的对比分析

介绍钢结构应用技术在国内外的应用及其面临的防火挑战,在例举钢结构几种防火措施的基础上,对比分析各种防火措施的优缺点,最终提出性能化防火设计是必然趋势。     

A study of professional perspectives on structural frame selection

The choice of an appropriate structural frame can contribute to effective short‐ and long‐term performance, and enhance client satisfaction but limited research indicates that the issues taken into account during structural frame selection are not very well understood. With this in mind, a major research programme, including interviews and an industry survey, examined the attitudes of project managers, cost consultants and construction clients in analysing the issues they typically consider when choosing the structural frame for a building, and to provide insights about how such decisions are made in practice. Ten key issues were identified as being the most important affecting structural frame selection, but the extent to which different parties considered these and at what stage was found to vary. Also, the variations, between what these parties themselves think of the issues and what others perceive their attitudes to be, were examined. In particular, the results showed that what clients perceive differs considerably from how clients’ views are perceived by others. For instance, according to cost consultants and project managers, their clients’ preference to regularly select a ‘preferred’ frame type or material is a far more widespread tendency than clients themselves actually acknowledged.     

Strengthening the substructures of residential buildings

Strengthening of the foundations of the basement portions of residential buildings by the installation of vertical reinforced-concrete girdling walls and broadening of the lower surfaces of the foundations beneath the bearing walls is described in connection with possible manifestation of karst-suffosion processes.     

结构的抗火分析和损伤等级评定初探

提出了需要对结构进行抗火分析的情况,介绍了抗火分析的方法和步骤,给出了构件火灾损伤等级的评定标准,通过确定一四面受火柱截面温度场的详细过程,叙述了针对钢筋混凝土结构的抗火分析方法。     

干粉消防车的结构分析及关键件的设计计算

通过对干粉消防车的用途、结构、干粉灭火剂种类及干粉消防车中关键部件的计算分析,对干粉消防车的日常使用、维修及保养具有一定的指导和借鉴作用。     

铁路简支梁桥下部结构健康状态动力评估方法研究

提出一种以实测横桥向整体振动、横桥向局部振动和顺桥向局部振动模态的不同组合为输入,采用模型修正技术和优化算法识别铁路简支梁桥下部结构的物理参数,从而实现对墩身、基础和支座病害进行定位和定量分析的动力学方法。进一步,建立了针对下部结构系统中各构件的评估准则和评估流程。对两座铁路桥梁进行现场试验,并依据所提评估方法和评估准则对其健康状态进行评估,理论分析结果现场评估结果一致,从而证明所提方法的准确性和有效性。     

A comparative study on optimization of constrained layer damping treatment for structural vibration control

This paper presents a comparison of optimization algorithms for constrained layer damping (CLD) patches’ layout with an objective to minimize the maximum vibration response of the odd modes, which constitutes the dominant acoustic radiation, of a simply supported beam excited by a harmonic transverse force. An analytical model developed for relating the displacement response of the beam with bonded CLD patches and their layout is adopted to formulate the optimization problem. Four different nonlinear optimization methods/algorithms, sub-problem approximation method, the first-order method, sequential quadratic programming (SQP) and genetic algorithm (GA), are then, respectively, used to optimize the CLD patches’ locations and lengths with the aim of minimum displacement amplitude at the middle beam. The efficiency of each considered optimization method is evaluated and also compared in terms of obtained optimal beam displacement and the added weight owing to damping treatment. The results show that GA is most efficient in obtaining the best optimum for this optimization problem in spite of highest computation efforts required to improve its stability.     

基于结构设计的基础隔震结构高宽比限值的研究

本文研究了橡胶支座基础隔震结构的高宽比限值。研究基于保证隔震结构在强震中不倾覆的两个充分条件,一个是橡胶隔震支座不能产生拉应力,另一个是隔震支座压应力不超过容许值。本文推导了隔震结构高宽比限值的显式并给出了针对不同建筑类别、不同设防烈度、不同场地条件和不同隔震层阻尼比的高宽比限值。在支座的轴力计算中,还考虑了竖向地震作用和荷载的最不利组合。研究发现,当控制条件为支座不产生拉应力时,高宽比限值随隔震结构周期的增加而增加;当控制条件为支座压应力不超过容许值时,高宽比限值随隔震结构周期的增加而减小。因此,存在一个临界周期使高宽比限值取得极大值。研究还发现,存在一个最大的隔震结构周期使高宽比限值等于零或隔震层位移超过容许值。将隔震结构的周期与临界周期和最大隔震周期比较,就可以得到相应高宽比限值的表达式。最后,按照简单、安全的原则,将各种工况下的高宽比限值进行了归并,给出了高宽比限值的设计建议值。同时,还按设计规范提供的结构周期计算公式计算了隔震结构的高度限值。     

A method for progressive structural crashworthiness analysis under collisions and grounding

Collisions and grounding always give rise to structural crashworthiness issues involving crushing, yielding, and fracture. For accidental limit state design and safety assessment associated with collisions and grounding, the resulting progressive structural crashworthiness characteristics should be analyzed to evaluate the energy absorption capability of the structure in the corresponding accidental event in conjunction with the associated criteria. The accidental energy absorption capability of a structure under collisions or grounding can be predicted by integrating the area below the reaction forces versus penetration curve until or after the accidental limit state is reached. For risk assessment associated with such accidents, the results of structural crashworthiness analysis are also used as a basis of the consequence analysis. The aim of the present paper is to present an efficient and accurate method which is useful for the progressive structural crashworthiness analysis of ships and ship-shaped offshore structures under collisions or grounding. Theoretical outline of the method is addressed. Application examples of the method to ship-shaped test structures are presented by a comparison with experimental results.     

A benchmark study on importance sampling techniques in structural reliability

Several widely used importance sampling methods for the estimation of failure probabilities are compared. The methods are briefly reviewed, and a set of evaluation criteria for the comparison of the methods is chosen. In order to perform a fair comparison the developers of the schemes were asked to solve a number of problems selected in view of the evaluation criteria. Their solutions are presented and discussed. Conclusions about the performances of the schemes under different circumstances are given.     

高层建筑工程结构设计综合分析

从目前我国高层建筑工程结构设计中存在的问题入手,根据高层建筑工程结构设计原则探讨了高层建筑结构优化设计方法,以及未来演变模式,以使高层建筑结构设计更加完善,以确保安全。     

结构性软土动剪切模量试验对比研究

以福州盆地广泛存在的三层结构性软土为研究对象,首先阐述了三者的沉积特征及常规物理力学性质,然后利用共振柱试验仪进行了一系列不同固结应力下动力试验,得到三层结构性软土在动荷载作用下的动剪切模量G,通过理论分析给出其归一化动剪切模量G/Gmax随剪应变γ变化关系G/Gmax-γ曲线,进而分析不同结构性软土试验结果的差异.试验及分析结果加深对福州盆地结构性软土动力特性的认识,也为进一步了解福州盆地场地地震效应提供了可靠的数据.     

Directional methods for structural reliability analysis

Directional simulation reduces the dimension of the limit state probability integral by identifying a set of directions for integration, integrating either in closed-form or by approximation in those directions, and estimating the probability as a weighted average of the directional integrals. Most existing methods identify these directions by a set of points distributed on the unit hypersphere. The accuracy of the directional simulation depends on how the points are identified. When the limit state is highly nonlinear, or the inherent failure probability is small, a very large number of points may be required, and the method can become inefficient. This paper introduces several new approaches for identifying directions for evaluating the probability integral — Spherical t-design, Spiral Points, and Fekete Points — and compares the failure probabilities with those determined in a number of examples in previously published work. Once these points have been identified for a probability integral of given dimension, they can be used repeatedly for other probability integrals of the same dimension in a fashion analogous to Gauss Quadrature.