核二级电动闸阀抗震分析

应用有限元分析方法对核二级电动闸阀进行抗震分析与评定.先计算阀门整机的固有频率,然后采用等效静力方法计算阀门在承受地震载荷及设计组合载荷共同作用下的应力,然后根据ASME规范作出应力评定和强度校核,从而验证核二级电动闸阀在SSE地震载荷及设计组合载荷作用下的结构完整性.     

核级风道调节阀的抗震分析

为了验证阀门的抗震性能,基于有限元分析方法,应用NASTRAN计算阀门整机的振动模态以及在承受地震载荷及组合载荷共同作用下的应力及变形,然后根据ASME规范对承压边界部件作出应力评定和强度校核。结果表明,该核级风道调节阀在地震载荷及组合载荷作用下能保持结构完整性。     

基于有限元法的核工程液压系统抗震研究

核工程液压系统属于抗震Ⅰ类机械设备,在极限安全地震震动(SL-2)引起的载荷作用下,必须保持其功能性。根据核安全法规要求必须对抗震Ⅰ类机械设备进行抗震性能鉴定。本文根据液压系统结构及工况特性,采用有限元法,对核工程液压系统有限元模型进行模态分析和谱分析,并通过计算,评估了核工程液压系统在地震条件下的抗震性能,为核级设备抗震研究提供了一定参考。     

基于ANSYS的抗震机柜有限元分析

有限元法是机柜设备抗震分析与评价的重要数值仿真工具。文中利用ANSYS程序,对福清核电厂"华龙一号"机组某设备抗震机柜采用等效静力法与反应谱法相结合进行有限元分析。最后根据相关法规对结构进行评价。确保机柜在极限安全地震条件下能够保持其结构完整性。     

核级风阀抗震分析

应用NX-NASTRAN对核级阀进行抗震分析,计算了阀门的固有频率。采用等效静力法计算阀门在承受地震载荷及组合载荷共同作用下的应力及变形,并根据ASME AG1标准作出了应力评定和强度校核。从而验证核级风阀在预定载荷下能满足结构完整性。     

核级气液驱动装置抗震设计与分析

基于振动力学原理,对驱动装置进行结构优化设计,通过ANSYS Workbench对气液驱动装置模型进行了模态及静应力分析。结合等效线性化应力分析方法,根据ASME BPVC-Ⅷ的相关要求,分别对驱动装置主要部件进行了地震载荷作用下的结构完整性和可运行性评价。结果表明,驱动装置在核级使用工况下,均能保持结构的完整性,运行良好,有限元分析方法可用于复杂结构的振动特性分析,优化核级产品抗震性能。     

核电厂堆芯补水箱抗震鉴定分析

随着我国核电厂建设的加快,使得相应的核级设备的鉴定问题变得突出。对于某些特定的核级设备,由于受现有试验台条件所限或自身特点要求,只能采取分析的方法对核级设备进行抗震鉴定。针对这一问题,给出采用分析方法进行核级设备抗震鉴定的使用条件、方法和步骤;采用分析方法对堆芯补水箱进行了抗震鉴定分析:建立有限元分析模型;给出与抗震分析相关的载荷组合和应力限值;应用有限元软件ANSYS对堆芯补水箱进行静力分析、预应力模态分析以及反应谱分析;根据应力限值,评估堆芯补水箱在地震条件下的安全性能。为采用分析方法进行核级设备抗震鉴定提供参考。     

基于ANSYS的桥式抓斗卸船机结构抗震性能分析

针对桥式抓斗卸船机在地震作用下的动态响应和抗震性能问题,对卸船机结构在地震作用下的结构强度、应变特性、轮压稳定性以及损伤模式等方面进行了研究,提出了基于ANSYS的结构抗震分析方法。结合传统岸桥和建筑抗震分析理论,利用ANSYS建立了桥式抓斗卸船机钢结构有限元模型,对卸船机在不同工况和不同地震激励下的位移响应、应力响应和轮压进行了地震等效静载分析计算,明确了卸船机的关键位置。在等效静载分析的基础上,根据拟建场地的基础特性和卸船机的结构振动特性,选取了合适的抗震设计反应谱和典型地震波记录,对卸船机主要工况在不同地震激励下进行了反应谱分析和动力时程分析,并将其与等效静载分析的实验数据进行了对比研究。实验结果表明:桥式抓斗卸船机有较好的抗震性能,满足规定的抗震设防烈度7度,保证了其钢结构设计的正确性,对卸船机的抗震研究领域和工程应用具有参考意义。     

核电站地震监控系统机柜抗震分析

采用有限元分析方法,利用Ansys程序计算了核电站地震监控系统机柜固有频率,然后采用谱分析方法计算了机柜在自重、地震载荷下的应力和变形,并根据ASME规范进行评定,结果表明抗震机柜的设计满足规范要求。     

核电厂大容量柴油发电机组公共底架的抗震分析

采用有限元分析法,对某核电厂备用柴油发电机组公共底架进行结构抗震计算分析。介绍了该结构的力学建模过程、载荷的组合工况和使用限制,以及地震响应求解方法。计算得到了结构的固有频率、振型和地震载荷下的响应,并根据ASME规范对结构在重力、地震载荷组合下的应力进行评定和强度校核,结果表明该公共底架的结构强度满足规范要求。     

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.