时速400公里高速列车底架拓扑优化

运用OptiStruct软件,针对400km/h高速列车车体,计算其在重要载荷作用下的结构强度、刚度以及模态分析后,以列车的底架作为研究对象,对其进行拓扑优化设计.结合OptiStruct中的OSSmooth模块和SOLIDWORKS软件,总结分析不同载荷方式作用下得出的拓扑优化结果,确定车体底架结构内筋的分布,得出最佳截面形状,并对优化后的底架结构及车体进行静强度以及模态分析比较.对比得出,优化后底架结构减重6.82％,满足车体强度、刚度及模态频率等性能要求的同时,改善了结构的应力分布.     

少片变截面板簧有限元分析方法研究

以某型少片变截面板簧为研究对象,对其进行强度与刚度性能分析,仿真计算结果值与实验结果值对比误差在6.2%以内,表明该评价少片变截面板簧刚度与强度性能的有限元分析方法有效、可行,可以广泛应用于少片变截面板簧的设计中。     

MEMS中变截面梁弯曲数学模型的建立

在MEMS结构中采用变截面梁来减小应力集中的影响。建立的变截面梁弯曲数学模型可为MEMS器件加工工艺提供理论依据。以增加空间利用率且保持最大转角和最大挠度不变为前提条件,分别构建了最大转角尺寸刚度Kφ和最大挠度尺寸刚度KW表达式;对比原设计参数的尺寸刚度,创建了梁长度和端面高度与尺寸刚度的关系式,从而为MEMS结构中梁的设计提供了理论支撑。     

大型模锻液压机活动横梁整体工作性能有限元分析

利用Marc有限元软件建立活动横梁的三维有限元模型.通过分析发现横梁的刚度不足,致使中梁之间有两处开缝;强度较薄弱存在两处,分布在拉杆的圆柱孔边和穿孔缸附近的倒角处.针对中梁之间的开缝,提出两种修正方案:一是在中梁中间孔和穿孔主缸周边布置一定数量的加强筋板;二是改变中梁和垫板组间的高度,调整中梁的垫板组之间的相对刚度.分析结果表明,两种方案对中梁的刚度均有不同的改善作用,布置加强筋后,中梁中心最大位移减小24.2%,相对挠度减小30.7%,开缝距离最大减小54.5%;垫板组的高度增加30.7%后,中梁中心最大位移减小33.4%,相对挠度减小50.5%,开缝距离最大减小64.9%.分析结果对于大型压机设计具有参考价值.     

出口印度调车机车底架结构的设计

主要介绍了出口印度调车机车车体底架各组成部分的结构特点,通过ANSYS软件对底架进行了有限元模态分析,证明了该车型底架强度、刚度满足使用要求。     

动车组座椅底架结构分析及优化设计

通过对动车组座椅底架的结构分析,并构建简化的力学模型,以底架纵梁的截面面积为目标函数,最大挠度和强度为约束条件,采用优化设计的方法,找到满足挠度和强度要求时,梁截面直径和壁厚的最佳取值点。     

起重机伸缩臂最优截面形式的研究

利用ANSYS有限元分析软件的APDL语言进行二次开发,完成臂架参数化建模,分析不同截面参数的变化对臂架刚度、强度及稳定性的影响程度,确定了影响臂架结构整体性能的主要因素和相对次要因素,并对其截面尺寸进行优化．分别以臂架的刚度、强度及稳定性作为性能指标,对伸缩臂结构模型进行性能参数优化,得出不同条件下的最优截面形式．     

基于ANSYS的矿井箕斗底架的强度分析与结构改进

运用有限元分析软件ANSYS对矿井斜坡道人车箕斗底架进行了结构强度分析。分析表明底架在典型工况下的强度满足要求但应力富余较大。在分析结果的指导下,对底架结构进行了相应的改进,使得应力富余减少,重量减轻。结构优化方案为技术改造提供了有益的参考。     

车身的最优承载度及正向概念设计方法

在车身结构正向概念设计阶段,确定最优承载度对指导非承载式纯电动汽车车身轻量化设计具有重要意义。针对模块化的纯电动汽车结构建立了车身的简化几何模型;确定了多点集中载荷作用下非承载式车身承载度与耦合力的函数关系;建立了耦合力作用下车身与车架一致性回传刚度链计算模型;以弯曲刚度为约束条件,以整车质量最轻为目标函数进行优化,得到某款非承载式纯电动汽车的车身与车架各自承受载荷的最优比例及各梁简化截面属性参数。最后利用有限元法建模计算,验证了本文研究方法的合理性和有效性。     

电动改装轿车车身结构拓扑优化分析

把拓扑优化设计理论引入某电动改装车的承载式车身设计，利用先进的有限元分析软件，在电动改装轿车车身结构拓扑优化分析中实现了多工况、多状态变量条件下的拓扑优化设计，确定了下车身的最佳结构方案，进而在此基础上建立了新的有限元模型，并进行了模态、刚度和强度分析，设计出最终的下车身改造结构。     

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.     

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。     

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....     

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.