电脑刺绣机横梁弯曲振动固有频率研究

以2头电脑刺绣机横梁为研究对象，分别运用简单梁理论，ANSYS有限元模拟和实验测试三种方法计算分析了电脑刺绣机横梁弯曲振动的固有频率，所得结论可用于电脑刺绣机横梁长度、截面形状和固定方式的改进设计。     

刺绣机横梁的模态分析及优化设计

以GY920A型电脑刺绣机的主横梁作为研究对象,分别运用实验测试和有限元模拟方法分析了电脑刺绣机横梁弯曲振动的固有频率,并将所得结果用于电脑刺绣机横梁结构的优化设计,提高了横梁的固有频率,达到减小断线率的目的。     

谐波减速器刚轮的模态分析

以XB-80-134H谐波减速器的刚轮作为研究对象,运用有限元分析的方法,对其施加满足实际工况的约束,在计算机容量允许的情况下,选择精度更高的单元,计算出刚轮的模态频率以及模态振型。为了验证有限元法计算结果,又通过实地的振动试验,具体测出了刚轮的共振频率,验证了有限元计算结果的正确性。利用经过验证的有限元模型,在计算机上作结构改进仿真设计。通过多种方案比较,发现加大刚轮轴上凸台的半径,可以实现在不改动谐波减速器其他零件尺寸的前提下,提高刚轮的模态频率,使谐波减速器更不易发生共振。     

电脑刺绣机横梁的模态分析

以GY920A型电脑刺绣机的主横梁作为研究对象．分别运用实验测试和有限元模拟方法分析了电脑刺绣机横梁弯曲振动的固有频率，并将所得结果用于电脑刺绣机横梁结构的改进，提高了横梁的固有频率，达到减小断线率的目的。     

电脑刺绣机横梁的模态和动态响应分析

以RF1201型电脑刺绣机的主横梁作为研究对象,分别运用实验测试和有限元模拟方法分析了电脑刺绣机横梁弯曲振动的固有频率和动态响应,并将所得结果用于电脑刺绣机横梁结构的改进,减小了机头的振幅,达到减小断线率的目的.     

电脑刺绣机横梁的有限元动态分析

研究电脑刺绣机横梁有限元模型的建立,重点研究其复杂约束在有限元分析中的简化,得到了与实际等效的有限元计算模型。     

轴向柱塞泵的模态仿真

以斜盘式轴向柱塞泵作为研究对象,运用有限元分析的方法,对其施加满足实际工况的约束,在计算机容量允许的情况下,选择精度更高的单元和划分更细的网格密度,计算出柱塞泵的固有频率以及模态振型.为了验证有限元法计算结果,又通过实地的振动试验,具体测出了柱塞泵的共振频率,验证了有限元计算结果的正确性.利用经过验证的有限元模型,在计算机上作结构改进仿真设计,找到提高柱塞泵共振频率的措施.通过多种方案比较,本文采用将柱塞泵前端的圆柱滚子轴承改成深沟球轴承,可以实现在不改动柱塞泵其他零件尺寸的前提下,提高柱塞泵的模态频率,使柱塞泵更不易发生共振.     

某商用车仪表板横梁模态和静刚度分析

对某商用车仪表板横梁(cross car beam,CCB)有限元分析过程进行研究,提出了仪表板横梁模态有限元分析的简化方法,并根据仪表板横梁设计规范,对仪表板横梁进行模态分析和静刚度分析,同时对未满足仪表板横梁设计规范要求的结构进行优化和加强,使之满足设计规范要求后,在试验条件不足的情况下,通过简易的仪表板横梁模态试验和静刚度试验,来验证仪表板横梁有限元模型和带上各个内饰件后仪表板横梁的一阶整体模态仿真结果的准确性,为整车强度、刚度和碰撞等仿真分析提供准确的仪表板横梁有限元模型。     

船体外板水火成型机器人Y轴横梁变形计算和模态分析

对船体外板水火成型智能机器人的重要部件——Y轴横梁进行了有限元静力学分析和模态分析。采用三维十节点四面体结构单元计算Y轴横粱在各种典型工况下的变形，提取变形规律。在此基础上，对Y轴横梁进行模态分析，求解出前5阶的固有频率和相应频率处的振动模态，验证其设计结构的可行性。同时，也为后续的加工精度分析和误差补偿提供了理论依据。     

柴油机体结构有限元模态分析和模态测试

为了解决某科研项目问题,需要利用有限元分析软件ANSYS对某柴油发动机机体结构建立有限元模型,并进行自由模态分析计算,从而得到该机体结构的低阶振动模态频率与模态振型。在得到有限元模型后需要对该机体结构进行模态试验测试加以对比验证。通过有限元模态分析与模态测试结果的对比,验证了有限元模态分析模型与结果的合理性,为该类型发动机机体结构设计与优化提供了参考依据。     

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.