汽车消声器隔板一模三件成型级进模设计及应用

通过对比分析汽车消声器隔板冲压件单冲模和级进模的冲压工艺,阐述级进模冲压工艺所具有的效率及成本优势,并着重介绍消声器隔板一模三件成型级进模排样工艺及模具结构设计,以及介绍相关设备选择方法,对同类型级进模技术的开发具有一定的参考价值。     

级进模CAD冲压特征工序设计自动化的研究

介绍了级进模CAD系统中，冲压工艺特征工序设计自动化方法。建立了冲压工艺特征的计算机模型和冲压工艺特征库，提出了设计零件上的冲压工艺特征和冲压工艺库的特征进行匹配的技术和算法，给出了特征参数的计算方法。探讨了这种技术在级进模CAD系统中的实现。     

基于变密度法的级进模模具结构拓扑优化设计

针对多工位级进模模具,提出了一种基于变密度法的级进模模具结构拓扑优化方法。先通过板材冲压成形有限元数值模拟得到变形板料对模具的作用力,利用自主开发的载荷映射工具构建级进模模具结构分析的力边界条件;再通过模具结构分析,明确模具结构优化的空间;最后结合拓扑优化算法对模具结构进行了优化设计。以某汽车连接器件级进模模具为例对该方法加以验证,与按传统方法设计的模具相比,优化重构后的模具在重量保持不变的情况下最大变形量减小了36.5%。对优化重构后的级进模在冲压成形过程中的应变值进行了测量,应变实测值与结构分析结果比较吻合,表明文中所提出的级进模模具结构拓扑优化方法是切实可靠的。     

某汽车底梁加固件冲压成形全工序数值模拟分析

为了减小模具开发周期和提高产品成形质量,CAE软件在板材冲压成形数值模拟分析方面得到了广泛的应用。以某汽车底梁加固件为研究对象,采用Dynaform有限元软件、多工位多工序的建模方法对其进行了冲压成形全工序数值模拟,以FLD图为根据评判制件冲压成形质量,并对底梁加固件进行了级进冲压试验,结果表明数值模拟结果与实际试模效果比较符合,所获得工件厚度值的最大相对误差仅为2.94%,说明所建立的全工序级进冲压有限元模型是合理可靠的,能够有效地指导实际生产。     

弹性阀座加工方法的改进

对弹性阀座的机械加工工艺和冲压加工工艺进行了对比,并分析了冲压加工所产生的误差,介绍了冲压加工的特点及级进模的结构。     

CPU连接器端子冲压工艺分析及高速精密多工位级进模设计

分析CPU连接器端子冲压工艺及高速精密多工位级进模具设计中的技术难点,介绍其复杂折弯高速精密级进模具的总体结构,重点论述工位设计、排样图设计、高速模具结构设计及关键零件设计等技术,并简要介绍高速精密级进模主要零/部件的加工工艺.实践证明,模具结构合理可靠,能保证产品质量,冲压速度可达1000冲次/分钟以上,对此类零件的级进模设计有参考价值.     

级进模冲压加工过程的计算机仿真

论述了计算机仿真技术在冲压工艺及级进模结构设计中的应用。针对某一典型级进模冲压工艺过程进行了计算机仿真,并建立了主动性对象系统的Ｐｅｔｒｉ网仿真模型。     

板料成型CAE分析技术在汽车车身模具设计中的应用

采用板料成型CAE分析技术在计算机上对冲压工艺进行过程模拟，可在模具开发的前期预测制件在成型过程中的拉裂、起皱、减薄、划痕和回弹等缺陷，通过优化参数设置来改进冲压工艺，确保了工艺的成功率，大大降低了模具开发的风险，缩短模具开发周期，降低调试费用。对于产品设计上的冲压工艺缺陷，可以根据CAE报告，进行产品设计变更。     

操纵杆冲压工艺分析与模具设计

根据操纵杆的结构特点与生产要求,分析了操纵杆的冲压工艺,制定了适合操纵杆生产要求的冲压工艺方案,阐述了冲孔落料级进模、冲凸模和弯曲模的结构设计与工作过程。经生产验证,模具设计满足成形要求,对类似零件的模具设计具有一定的参考价值。     

前组合灯下安装支架多工位级进模设计

通过对前组合灯下安装支架的冲压工艺性及冲压工艺方案的分析,与单工序冲压模进行比较,确定了采用12工位级进模来进行制件成形的冲压工艺方案。随着工艺方案的实现,模具充分利用工件本身的结构特点,采用了自动卸料、出料冲裁,模具在压力机一次行程中完成自动送料、冲孔、成形、翻边、分离等工序。试冲结果表明,提出的排样方案和设计的12工位级进模是合理可行的,能满足大批量生产需要。     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.