乏燃料贮存格架在装载井中的抗震分析

为评估满载组件的两台乏燃料贮存栺架自由放置在装载井中的安全性,运用时程分析法对其在地震载荷下的响应进行分析。针对乏燃料贮存栺架在装载井内的布置情况,考虑了其与池底的摩擦接触、与贮存组件的碰撞接触以及在水池中的浮力、阻尼、流固耦合效应。通过计算可得到乏燃料贮存栺架在地震载荷下的位移及支反力结果。分析乏燃料贮存栺架的位移结果可知,其滑动位移与水隙宽度有关,且不发生倾覆,不与相邻物体发生碰撞。根据乏燃料贮存栺架所受支反力对栺架底板、支腿强度进行分析,确认无损坏风险。     

基于时间历程响应的核电站环吊抗震分析

针对地震反应谱分析法的不足,以某三代核电站环吊为研究对象,建立了环吊抗震计算模型,研究其在SSE地震发生过程中的抗震性能.运用ANSYS对环节进行地震时程响应分析,计算评估在SSE地震中吊车结构受力、变形等在地震载荷作用下的响应情况.抗震计算结果也表明,对核电站大吨位环吊进行地震时程分析,实施抗震性能设计校核,是非常重...     

乏燃料贮存格架自主化设计

乏燃料贮存格架是核电厂内存放乏燃料组件的关键设备,为了实现SNG乏燃料贮存格架的自主化设计,参考美国第三代核电技术AP1000乏燃料贮存格架的设计,并结合国内相关核电厂乏燃料贮存格架设计经验,优化了螺纹支腿等相关设计,并实现了该设备的国产化,特别是自主研制了中子吸收材料,并完成了各项安全分析并进行试验验证。自主化设计的乏燃料贮存格架在贮存容量、临界安全、抗震、热工水力等各方面性能均满足我国相关法规及标准的要求。     

乏燃料贮存格架制造工艺过程尺寸控制

为实现乏燃料组件的安全稳定贮存,对乏燃料贮存格架的制造精度提出了严格要求。在乏燃料贮存格架的制造过程中,根据其结构特点,确定了垂直度和栅距的工艺控制方法和检测方法。根据贮存套筒尺寸形状公差,利用蒙特卡洛法分析贮存套筒与连接块的装配间隙和角度,得到装配间隙和角度的频率分布直方图,确定了连接块尺寸的设计范围,提高了乏燃料贮存格架的装配质量。     

PIPESTRESS软件在主蒸汽管道抗震分析中的应用

在核电站设计中,地震是需要考虑的基准载荷,需要评估地震载荷产生的动态响应,以确保核电站物项(系统、结构及部件)的完整性。目前,国内外抗震设计的计算机仿真软件门类众多,功能各有侧重,但对地震载荷的计算方法主要有静力法、反应谱分析法和时程分析法。以管道有限元计算软件PIPESTRESS为工具,研究PIPESTRESS软件动力分析方法的理论公式;介绍反应谱分析法、通用响应分析法及真时程分析法3种分析方法的特点;总结3种分析方法的实现命令流和求解设置。以某核电站主蒸汽管道为例,对地震响应分别采用反应谱分析法、通用响应分析法及真时程分析法进行计算,并将计算结果进行对比分析,分析3种方法的保守性,为管道抗震计算方法的选取提供参考。     

谱分析与时程分析在抗震设计中的一致性研究

针对高耸结构抗震设计方法的选择问题,运用目前抗震计算方法中最具代表性的反应谱法与时程分析法,结合《建筑抗震设计规范》的基本要求,以塔式立体车库结构为研究对象,通过ANSYS有限元分析进行两种方法下位移、应力与层间位移角的计算并对其结果进行对比。结果表明,两种方法对车库抗震分析得到的结果数值相对误差在10%以内,满足实际要求,验证了两种方法在抗震设计中的一致性,为其在结构抗震设计中的应用提供了重要的理论支持与实际指导。     

基于时程分析法的全焊接球阀抗震特性分析

为研究全焊接球阀的抗震特性,本文以地震动规范反应谱为基础,从PEER地震动数据库选取天然地震波作为课题抗震性能分析研究的载荷,应用时程分析法和瞬态动力学分析计算方法,对球阀安装结构的应力及其变化规律进行了分析计算,并将计算结果与反应谱法计算结果进行对比,结果按照JB-4732《钢制压力容器—分析设计标准》要求进行评价。结果表明:全焊接球阀满足抗震性能设计要求,所采用的工程结构抗震性能瞬态动力学分析研究方法能够应用于全焊接球阀管线系统抗震分析,为今后天然气管道设备及构件的抗震性能分析研究提供了一种可参考借鉴的手段。     

某研究堆转接筒装置抗震分析与评定

某研究堆的转接筒装置主要实现乏燃料组件等物项在堆芯和燃料水池间的转运,该装置为抗震I类设备,在设计时需满足抗震要求。利用有限元分析软件ANSYS对转接筒装置进行了建模和模态分析,根据模态分析结果采用反应谱法进行了运行基准地震(OBE)及安全停堆地震(SSE)下的动力特性应力分析计算,并按照RCC-M规定进行了各工况下的载荷组合,最后依据RCC-M中的应力评价准则进行了各工况下的应力评定,结果表明转接筒装置满足抗震设计要求,具有良好的可靠性。     

乏燃料干法贮存容器内腔气体杂质含量分析

国内少数核电站已开始采用乏燃料干法贮存技术路线进行乏燃料的中间贮存。为防止乏燃料组件在长期贮存过程中燃料包壳因干法贮存容器内腔杂质中的氧化性气体发生性能降解和破损,导致包壳内的放射性气体泄漏到容器中,需控制容器内腔中的氧化性气体含量。文中根据国内代表性的乏燃料干法贮存容器参数提出容器内腔杂质气体含量分析的包络性假设条件。对容器装料过程中容器内腔杂质气体的来源进行了分析,并预估了装料过程中的杂质气体含量,计算了长期贮存过程中容器内腔气体的最大泄漏量。经过对比分析,得出了容器内腔杂质气体的主要来源,并提出了解决办法,为乏燃料干法贮存装料操作工程应用中的技术指标设置提供了参考。     

核岛燃料贮存格架自动引入系统的应用研究

随着科技的发展,智能化起重装备已日趋成熟。性能稳定、质量安全可靠的先进起重装备是现阶段企业发展所迫切需求的。基于核岛燃料厂房乏燃料贮存格架自身结构特点及燃料厂房环境的局限性,在保证安全和质量的前提下,为满足乏燃料贮存格架的顺利引入,一种应用于核岛燃料厂房的乏燃料贮存格架自动引入装置是核岛安装现场迫切需要的,以减少人力物力浪费,降低质量安全风险,提高工作效率,实现提质增效、精益施工的目的。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.