具有两个附着点的塔机结构二阶效应分析

对具有两个附着点的塔机结构二阶效应分析提出了相应的简化计算模型,对该简化模型进行了弹性二阶效应分析并与ANSYS有限元软件分析计算的结果进行了比较。最后对FZQ2000Z型自升式塔机实际结构进行了有限元分析计算,与相应简化模型分析结果进行了对比分析。     

基于ANSYS的梁板结构振动疲劳分析

对有限元软件ANSYS的疲劳分析机理进行了阐释,建立了梁板结构的有限元力学模型并对后处理结果进行了简要分析,最后利用ANSYS振动分析的结果进行疲劳计算。振动响应特性分析的结果以及随机疲劳的计算分析对实际的板壳结构设计具有一定的指导和参考价值。     

插入式钢管承压板锚固承载能力试验研究

对插入式钢管的承压板锚固模式进行了有限元理论分析和试验分析,并根据有限元分析结果和试验分析结果,对日本标准中的相关设计公式进行了修正。     

成都双流国际机场航站楼空调系统用能状况分析与节能诊断

根据调查统计数据和实际测试结果,分析了该航站楼实际能耗状况及用能特点,结合分析结果,对空调系统存在的问题进行了节能诊断和分析,提出了节能策略和改进方法,并对结果进行了监测与分析.     

济南奥体中心体育馆火灾后检测鉴定

济南奥体中心体育馆火灾后,对主体钢结构采用了对比硬度回弹和钢材金相组织分析的方法进行现场检测,同时对网壳变形进行测量,对构件内力补充监测数据,并进行结构内力计算与分析。将检测结果、变形测量结果、构件内力监测数据与理论计算分析结果进行比较分析,对火灾后结构的安全性做出正确的鉴定评价。     

某混凝土框架工厂火灾后结构检测与鉴定

对火灾后某多层框架进行了现场检测,通过外表观测对构件进行了初步鉴定评级。利用取芯法、回弹综合法、超声波平测法,对火灾最高温度进行了分析,对火灾后混凝土损伤深度进行了分析。根据现场检测结果及分析结果评定结构损伤情况,并提出了加固建议。     

江苏新长江(雅阁)国际酒店B塔楼结构分析与设计北大核心CSCD

江苏新长江(雅阁)国际酒店B塔楼结构高度为126.4m,属超高层结构。对结构进行了多遇地震下的反应谱分析,为了使分析结果安全可靠,分别运用PKPM和ETABS两种软件对结构进行分析,并将结果进行对比。结果表明,两种软件求得的结构各主要参数结果都基本一致,误差很小,从而证明了计算结果的正确性。在反应谱分析的基础上,利用ETABS软件对结构进行了弹性时程反应分析,时程分析时选取了2条天然波和1条人工波,分析结果显示,时程分析的结果基本都小于反应谱分析的结果。在多遇地震分析的基础上,选取了几个主要结构构件进行了中震不屈服校核,结果显示,构件能够满足中震不屈服的性能目标。     

苏州G32号地块项目塔楼超限高层结构设计北大核心CSCD

苏州G32号地块项目塔楼为B级高度的超限高层建筑,对该项目东塔楼进行结构计算,分析结果的合理性,同时按规范要求对关键构件进行了抗震性能化设计。计算结果和规范限值的对比表明,东塔楼结构布置合理,能满足抗震规范的设防要求。同时对斜撑构件进行了详细的应力分析,对楼板进行了温度应力分析,并将结果用于施工图设计。     

钢-混凝土组合楼盖抗火性能的试验研究

为了考察火灾下组合楼盖的破坏特征,研究组合楼盖在火灾下的结构性能,本文对4个钢.混凝土组合楼盖试件在不同荷载水平下的抗火性能进行了试验研究,对试验现象和结果进行了分析和解释,并采用作者编制钢-混凝土组合楼盖抗火性能分析程序对试件进行了分析,通过温度和位移的分析结果与试验记录结果的对比,验证了分析理论和程序的可靠性,并对产生误差的原因进行分析。     

基于ANSYS的薄壁箱梁剪力滞效应分析

通过大型有限元分析软件ANSYS对一具体箱梁剪力滞进行有限元求解,对ANSYS计算结果与变分法计算结果进行了对比分析,提出了利用ANSYS对薄壁箱梁剪力滞进行有限元求解是精度很高的方法。     

Numerical and experimental analyses of multiple-dowel steel-to-timber joints in tension perpendicular to grain

The behaviour of dowel-type steel-to-timber joints loaded in tension perpendicular to grain is analyzed experimentally and numerically. Two main types of failures are observed in the experiments such as wood splitting and embedding. The experimental results are used to validate a three-dimensional (3D) non-linear finite element model. The non-linear model uses the Hill criterion to control the plastic yielding of wood material. The Hoffman failure criterion, controlling the damage evolution in wood, is used to take into account the brittle failure in shear and tension perpendicular to grain. The comparison with experimental results shows that the numerical results are in good agreement with them. The validated model is used to investigate the effect of some influential parameters on the splitting strength of the joints loaded in tension perpendicular to grain. Besides, the splitting strengths given by the numerical model are used to evaluate the accuracy of some analytical formulae available in the literature.     

Post-cracking behaviour of steel and macro-synthetic fibre-reinforced concretes

The present paper describes the results of an experimental investigation on the performances of concrete specimens reinforced with either steel or macro-synthetic fibres under three-point bending. Steel fibres are often used to improve the flexural toughness of concrete and are used in various structural applications while synthetic fibres are more often used to reduce crack opening due to shrinkage. Macro-synthetic fibres have been proposed more recently with the aim of creating an alternative to steel fibres in structural applications but their use is still limited.In the tests performed, specimens cast with the same concrete mix, but containing different dosages of either steel or macro-synthetic fibres, were used and compared. In general steel fibres were more efficient in increasing the toughness of concrete than macro-synthetic fibres, even though their results were significantly more scattered.Test results were used to calculate the parameters of stress-crack opening relations via inverse analysis using a cracked hinge model. This numerical model provided results, in terms of force-Crack Mouth Opening Displacement (CMOD) curves, in very good agreement with the experimental data.     

Climatic conditions and migration: An econometric inquiry

"This paper has examined the impact of climate on migration. It has compared the results that are obtained when various indicators of climatic conditions, both those which have been used in the literature and those which have not, are included in a regression used to explain migration behavior. The results suggest that individuals do indeed consider climatic conditions in different areas when deciding where to live; people generally prefer areas which have moderate climates to areas which have either extremely hot or extremely cold climates. The results also indicate that the climate variables which yield the best results are generally those which have not been used in the literature." The study is based on U.S. data concerning in-migration to 36 SMSAs between 1960 and 1970.     

MODIFIED MONTE CARLO SIMULATION FOR PROBABILISTIC SCHEDULING

This paper presents the Simplified Monte Carlo Simulation (SMCS) method. The SMCS method can be used to perform risk analysis of construction networks, and produce results as accurate as Monte Carlo Simulation (MCS) while requiring less computing time. Thirty-one construction networks were used to compare the SMCS results with MCS results. Two cases are presented in this paper. SMCS performs the same type of replications as MCS but in a smaller network, reducing computing time from fifteen to seventy percent when compared with MCS. Moreover, SMCS can be used to identify activities that are more likely to cause delay of the project, as well as activities that are not likely to have impact in the duration of the project.     

地铁隧道-地层系统的参数优化反演与动力响应分析

由半解析方法研究地铁隧道-地层系统的动力参数优化反演和动力响应分析问题.隧道结构由平面等参单元离散,地层由层单元离散,采用半解析位移函数导出了相应离散系统的动力方程和频域中的最小二乘优化反演方程,由此,在给出参数反演的同时,给出了系统的动力响应分析.这种基于参数反演而进行的动力分析可以给出与实际相符的合理结果,对地铁系统的设计有一定的实用价值.     

PIV技术在非饱和冻土冻胀模型试验中的实现与灰度相关性分析

粒子图像测速法(PIV)已经在流体力学和岩土工程中得到广泛应用,并取得了良好的试验结果。但是,由于黏性土缺乏表面纹理,PIV技术尚未在冻结黏性土颗粒迁移分析中得到成功应用。针对黏性土冻结过程中的土颗粒迁移问题,采用自制的PIV冻土模型试验箱,以非饱和粉质黏土作为试验土样,结合Canon EOS 1300D相机和GeoPIV软件,提出了PIV技术在非饱和冻土中的实现方法。结果表明:(1)试验过程中光线的变化会极大的影响试验结果,故需要在摄影棚中构建恒定光场;(2)为便于PIV分析,试验前需对冻土进行表面纹理构建,粒径0.3 mm石英砂是纹理构建的最佳示踪粒子;(3)非饱和粉质黏土在冻结过程中的冰水相变会导致图像灰度变化,根据统计结果,将种子区域灰度相关性及整体灰度相关性分别调整为0.85和0.69。     

Joint modelling of obstacle induced and mesoscale changes—Current limits and challenges

Obstacles considerably influence boundary layer processes. Their influences have been included in mesoscale models (MeM) for a long time. Methods used to parameterise obstacle effects in a MeM are summarised in this paper using results of the mesoscale model METRAS as examples. Besides the parameterisation of obstacle influences it is also possible to use a joint modelling approach to describe obstacle induced and mesoscale changes. Three different methods may be used for joint modelling approaches: The first method is a time-slice approach, where steady basic state profiles are used in an obstacle resolving microscale model (MiM, example model MITRAS) and diurnal cycles are derived by joining steady-state MITRAS results. The second joint modelling approach is one-way nesting, where the MeM results are used to initialise the MiM and to drive the boundary values of the MiM dependent on time. The third joint modelling approach is to apply multi-scale models or two-way nesting approaches, which include feedbacks from the MiM to the MeM. The advantages and disadvantages of the different approaches and remaining problems with joint Reynolds-averaged Navier-Stokes modelling approaches are summarised in the paper.     

Behaviour of concrete-filled steel tubular members subjected to shear and constant axial compression

Concrete-filled steel tubes (CFST) are used extensively in modern civil engineering. In many cases, they are often subjected to shear and constant axial compression, particularly when being used in high-rise buildings. ABAQUS Programming is used in this paper for the analysis of CFST subjected to shear and constant axial compression. A comparison of results calculated using this model shows good agreement with test results in general. The theoretical model was used to investigate the influence of important parameters that determine the ultimate shearing strength of the composite members. The parametric studies provide information for the development of formulae to calculate the ultimate strength of CFST members subjected to shear and constant axial compression.     

The scaling of flows of energy and mass through stairwells

Simple physical and dimensional arguments are used to determine the laws relating the mass flow induced within a closed recirculating system representative of a domestic stairwell to the energy input driving the flow and the temperature differential established between chambers above and below the stairwell. Appropriate dimensionless groupings are introduced to characterise this kind of system. Experimental results obtained from a one-half scale model of a stairwell are used to validate the simplest analysis and to define the influence of a Reynolds number characteristic of the flow. The results are used to investigate the utility of models of various scales.     

某高层建筑钻孔灌注桩基础的设计、施工与检验

介绍某高层建筑钻孔灌注桩基础的分析计算和设计 ,并与静载荷试验进行对比 ,计算与实测结果比较吻合 ,证明此工程在该地区对岩土参数的取值和计算方法是恰当的。这一成功经验对类似项目具有一定的参考价值