TCT6513塔机结构建模分析

运用SAP84结构分析通用有限元软件对TCT6513塔式起重机整体结构进行有限元建模分析,对建模中的结构简化和边界条件处理等进行了探讨和分析。对建立的塔式起重机有限元模型进行了静力分析,将分析结果与该塔机现场试验结果进行比较,验证了模型的可行性。     

核爆等效静载作用下工字型钢梁截面优化设计

应用ANSYS有限元分析程序建立了工字型截面钢粱的参数化有限元模型和优化数学模型,用ANSYS参数化设计语言编制了有限元分析文件及优化控制文件,对梁截面进行优化分析,得到了工宇型钢梁的最优截面型式,该方法优化效果显著,且计算效率高。     

碳纤维加固墙体有限元分析

本文主要运用有限元分析的方法对碳纤维布加固砌体墙体进行研究,通过有限元分析软件建立有限元模型,对水平荷载作用下的未设构造柱、设置构造柱和碳纤维布加固砌体墙体进行变形和裂缝研究。     

齿轮有限元分析中的前处理技术

为了提高齿轮有限元分析的质量和效率,本文对齿轮接触有限元分析中的前处理问题进行了探讨。基于Ansys,文中重点讨论了齿轮网格划分技术和边界条件和载荷的施加技术三个关键性问题。这些方法对齿轮接触强度以及齿根强度分析具有指导意义。     

导管架储油平台的自振特性分析

结合渤海埕北油田的某储油平台的工程实例,利用有限元软件ANSYS建立了导管架储油平台在罐内液体为空罐、半罐和满罐三种工况的有限元模型,分别对三种工况的有限元模型进行自振特性分析,获得三种工况下的频率和振型,并对结果进行对比分析,为导管架储油平台的设计提供参考。     

混凝土重力坝振型分解反应谱可采用ANSYS软件进行分析

随着计算机的飞速发展和广泛应用以及有限元理论的日益完善,ANSYS等大型通用有限元分析软件被日益广泛的应用到水利水电工程结构设计中。文章介绍了用ANSYS软件进行混凝土重力坝振型分解反应谱平面有限元计算的方法和步骤,并简要介绍了静、动应力叠加的一般原则。对需进行抗震设计的混凝土重力坝结构设计有一定的指导意义。     

基于有限元软件的隧道开挖变形分析

采用大型非线性有限元软件模拟隧道开挖变形,建立了隧道开挖变形的二维有限元分析模型。利用有限元软件的单元寿命和死亡函数,对基坑开挖和支护过程进行了动态模拟。分析了单侧导坑法对隧道围岩变形的影响。结果表明,单侧导坑法引起的变形缩回隧道。穹顶的Z方向位移变化很大,Y方向的位移变化很小。另外,还分析了螺栓位移的变化,进一步说明了单侧导坑施工方法对隧道围岩变形的影响。此时,锚被拉起并起到悬挂作用。     

利用有限元软件ANSYS对钢桁梁桥进行建模

文章对有限元分析软件ANSYS，以及钢桁梁桥进行了简单的介绍，并利用大型有限元软件ANSYS对铜桁梁桥进行建模，为实际工程中的研究和计算提供了方便。     

基于ANSYS对简单直流制动器的电磁场有限元分析

文章针对直流制动器定子转子存在边缘效应特点,基于有限元分析软件ANSYS,开展了直流制动器在电磁场中的数值理论计算。通过全场域二维电磁场有限元分析,建立直流制动器的等效有限元模型,对特定简单的直流制动器磁场分布、静态特性、磁力线与磁通量等进行了计算分析,磁通量和动态转矩的计算值与实际数值结果非常接近,进而说明建立的有限元模型相对有效,尤其对制动器的稳态特性具有较高精度。     

考虑前三阶模态时悬索桥的车过载荷响应

本文通过Galerkin方法对经典的悬索桥垂向弯曲振动方程进行离散,得到了包含三个二阶方程的常微分组。通过该常微分方程组的解析解,研究了车过载荷作用下结构的动力学行为,并和有限元计算结果进行对比。研究结果显示,Galerkin方法得到的一阶、二阶振动频率和有限元结果一致,但三阶模态的振动频率比有限元的结果大;车过载荷作用下,三阶模态截断得到的解析解在整体运动趋势和有限元计算结果一致。因此,要较精确的描述悬索桥的动力学行为,需要考虑二阶和三阶模态。     

用PKPM系列程序优化分析高层结构的几点体会

介绍了作者应用PKPM系列的程序,在高层建筑结构设计计算中的体会,其中对若干抗震设计的控制参数的含义、电算分析与调整操作作了介绍,包括:位移比、周期比、侧刚比、受剪承载力比、剪重比、刚重比、层间位移角以及各种参数的调整等方面。供结构设计工程师参考。     

桩筏基础非线性共同作用分析及变刚度调平设计

桩筏基础的承载力、位移特征分析,尤其是建立在桩-土-筏共同作用基础上的以减小沉降差为目的的变刚度调平分析是目前桩筏基础设计的难点与热点。文章利用桩筏基础的非线性共同作用分析方法和分析程序,分析了桩筏基础当筏板厚度和桩距、桩长、桩径变化时,筏板的位移特性和桩顶的反力及其分布规律,得到了一些有意义的结论。利用本文的分析结果,进行桩筏基础的变刚度调平设计,以达到减少桩筏基础筏板沉降差的目的。     

堆积层滑坡位移矢量角异常变化分析——以新滩滑坡为例

基于新滩滑坡位移观测资料,运用数理统计均方差异常判据对滑坡失稳过程中的位移矢量角变化规律进行了初步的研究,发现随着边坡的失稳位移矢量角出现异常变化,表明位移矢量角具有较强的预测预报功能,说明在滑坡预测预报过程中,位移矢量角是一个不可忽视的变量。     

细分层注水井封隔器位移磁定位测井误差分析与控制

油田开展的精细分层注水需要对注水井封隔器在井下各工况的位移进行磁定位测量。本文研究了磁定位测井原理,分析了磁定位校电缆、测井过程测量误差的影响因素,确定了系统性误差与随机性误差的组成。制定了封隔器在井下各工况相对于自由悬挂状态的位移的测试方案。该方案抵消了系统误差,将封隔器位移的误差范围控制在±0.15米以内。采用该方案测试了某井五个封隔器在不同工况下的位移。     

Gentrification,Education and Exclusionary Displacement in East London

In this article we draw on Peter Marcuse's discussion of different types of displacement using evidence from a recent study we conducted in East London to argue that there is clear evidence of ‘exclusionary displacement’ and ‘displacement pressure’ in terms of education and specifically the choice of schooling. We show how the incoming middle classes in the Victoria Park area of inner East London have displaced not only existing poor residents but also many of the less affluent middle class from the favoured state schools in the area by adopting some schools and avoiding others. The preferred schools are often praised to the heavens whilst the shunned schools are similarly disparaged and deemed unacceptable. We suggest that it is this middle‐class dichotomization of schooling which accounts for the kind of educational displacement we have observed. The main form that this takes is direct exclusionary displacement when middle‐class pressure on favoured schools leads to local people being unable to get their children into them — normally because of ‘distance from school’ selection criteria.     

柔性测斜仪在公路边坡自动化监测中应用研究

为了深入理解营运高速公路高边坡深部位移的变形机理,更好地进行防灾减灾工作,使用阵列式位移传感器(SAA)对营运高速公路高边坡进行深部位移动态监测,并同时使用人工测斜仪进行数据对比分析。通过4G网络建立了无线数据传输系统,实现对边坡体全天候监测。试验结果表明:在营运高速公路高边坡深部位移监测中,使用阵列式位移传感系统与无线数据传输系统进行监测,不仅能够实时监测到边坡体深部位移的变形情况,还能判断出滑移面具体位置。相较于人工测斜仪监测,阵列式位移传感系统测量精度和效率更高,在公路高边坡监测中具有广阔的发展前景。     

Making the ‘Invisible’ Visible: Redevelopment‐induced Displacement of Migrants in Shenzhen,China

Gentrification in China is intertwined with urban redevelopment, which causes the large‐scale displacement of rural–urban migrants from ‘villages in the city’ (ViCs). Because of the informality of ViCs, migrant renters have very insecure tenancy and during redevelopment they are treated as a negligible (‘invisible’) social group. As they are very difficult to locate after displacement, they are also literally invisible to researchers. To make the invisible visible, this study traced a sample of displaced migrants from Huangbeiling village in Shenzhen. The focus was on the displacement process and on identifying the consequences for the displaced. We found various forms of displacement during the redevelopment process. Nearby ViCs were prioritized by displaced migrants to minimize as much utility loss as possible. However, they generally suffer from decreased proximity, increased living costs, and the loss of social networks and job opportunities. Remarkably, some choose to return to the gentrifying village, enduring displacement in situ caused by increasing rents, drastic physical neighbourhood changes and declining liveability, in exchange for retaining their original social and economic networks. Large‐scale urban redevelopment is causing the rapid shrinkage of informal housing. Recognizing and addressing the housing needs of this impoverished social group is a matter of urgency.     

Displacement and self-employment entry

Displacement is expected to decrease the reservation wage of self-employment by decreasing earnings in paid employment and increasing the probability of unemployment. This paper examines whether displacement increases the probability of self-employment using propensity score matching on Swedish register-based data. The data include all individuals displaced due to plant closures in 1987 and 1988, and a random sample of 200,000 employed individuals. The results suggest that displacement almost doubles the probability of entering self-employment the year after displacement. A sub-sample analysis indicates that individuals with a potentially worse position on the labor market react more strongly to displacement in terms of entering self-employment.     

‘Gentrification Without Displacement' and the Consequent Loss of Place: The Effects of Class Transition on Low‐income Residents of Secure Housing in Gentrifying Areas

The increasingly disputed concept of gentrification‐induced displacement is combining with the argument that the poor benefit from social mix to produce a theoretical case for ‘positive gentrification'. The notion that new middle‐class residents not only attract more investment but bring opportunities for ‘upward social mobility' to low‐income people who manage to stay in gentrifying areas has become policy orthodoxy. While there are scholarly challenges to the extent of these benefits, the disadvantages of imposed social mix on low‐income communities even where they are not physically displaced remain under‐researched. This article helps to fill this gap by reporting on research into the experience of long‐term low‐income residents of gentrifying neighbourhoods who managed to stay put. The research explores notions of social mix, place and displacement among residents of secure community housing in Melbourne, Australia (the equivalent of small‐scale social housing in Europe and North America) with the object of establishing whether the absence of physical displacement is sufficient to ameliorate gentrification's negative impacts. The findings demonstrate that transformations in shops and meeting places, and in the nature of local social structure and government interventions, cause a sense of loss of place even without physical displacement.     

加筋路堤的数值模拟分析

本文采用非线性有限元方法来分析加筋土坡的位移场,建立了3种计算模型,通过有限元分析,对一般土质地基上土工格栅加筋路堤的工作性能进行了研究,不同布筋方式的土工格栅加筋路堤及不加筋路堤进行了计算与分析,研究了各种工况下路堤整体变形情况以及路堤内位移分布、坡面侧移情况。结果表明:加筋能较大幅度地提高路堤的整体刚度和内部稳定性,对地基均匀性和抗变形能力的要求有所提高;加筋路堤边坡的水平位移随着路堤加筋位置的上移而增大。