乳化液泵曲柄滑块机构的运动仿真与有限元分析

以BRK500/37.5型乳化液泵曲柄滑块机构为研究对象,对曲柄滑块机构进行运动学分析,求解滑块的运动学方程。并利用UG软件的运动仿真模块对曲柄滑块机构作运动仿真分析,得出滑块在工作时的位移、速度和加速度仿真曲线图。最后利用ANSYS Workbench软件对滑块进行有限元分析,得出滑块在最大工作压力下的应力应变值,为曲柄滑块机构的改进奠定了理论基础。     

基于ANSYS WORKBENCH乳化液泵齿轮有限元分析

以BRK500/37.5型高压乳化液泵齿轮为研究对象,在三维建模软件UG中建立乳化液泵齿轮的三维模型,并进行装配。然后将三维模型导入到ANSYS WORKBENCH中,对齿轮进行结构强度分析,得出齿轮在作业时的应力和应变值。同时考虑动态特性对齿轮的影响,对齿轮进行模态分析,计算出齿轮的固有频率和振型,找到齿轮的薄弱部位,为乳化液泵齿轮的设计和研究提供理论依据。     

高压乳化液泵壳体有限元分析

以BRK500/37.5型高压乳化液泵壳体为研究对象,通过SolidWorks三维软件建立了高压乳化液泵壳体的三维实体模型,然后利用ANSYS WORKBENCH和SolidWorks之间的无缝连接,将做好的三维实体模型导入到ANSYS WORKBENCH软件中去,然后对高压乳化液泵壳体进行了有限元模态分析,从理论上得到了高压乳化泵壳体的多阶固有振动频率和振型特征。在此基础上对高压乳化泵壳体进行了分析,找到了高压乳化液泵壳体振动的敏感区域,为进一步高压乳化液泵壳体结构的改进和优化设计提供了良好的技术支持。     

高压乳化液泵壳体的有限元模态分析

以BRK500/37.5型高压乳化液泵壳体为研究对象,通过UG软件建立了壳体的三维实体模型。由于乳化液泵壳体的结构比较复杂,因此在建立其有限元动力学模型之前,进行了一定的简化,忽略了壳体受载较小或影响甚微的区域,如圆角、倒角、凸台、放油孔及各种螺栓联接孔等小结构。最后利用ANSYS WORKBENCH软件进行了壳体的有限元模态分析,得出其多阶固有频率和振型。通过分析,找出了乳化液泵壳体振动的敏感部位,为壳体结构的改进和优化设计提供了理论依据,具有重要的工程实用价值。     

乳化液泵及其吸排液阀的改进

为提升煤矿乳化液泵工作效率、降低其容积损失、提升其容积效率,在对影响乳化液容积效率因素分析的基础上,通过试验深层次分析了乳化液泵容积效率与压力、流量之间的关系。重点针对降低乳化液泵曲轴转速对其本身结构进行改进,对传统乳化液泵吸排液阀进行一体化设计,解决吸排液阀动作与柱塞动作不同步的问题,从而优化乳化液泵性能,增强支护效果。     

ANSYS在三叉杆滑块式万向联轴器中的应用

利用ANSYS有限元分析软件对三叉杆滑块式万向联轴器的销轴构件进行了应力分析，建立了该零件的有限元仿真分析模型，得出了该构件的应力应变分布情况，并进行了强度校核，为该联轴器的结构改进提供了依据。     

某型无人直升机变距滑块的改进与分析

以某型无人直升机变距系统为研究对象,分析其变距滑块工作原理,采用有限元方法进行计算分析,得出其磨损原因,继而对滑块部件进行了结构优化设计,并进行有限元分析对比。结果表明其应变明显减小,应力分布也更加均匀。实际使用试验也表明,滑块应变间隙明显减小,使用寿命大大提高。     

温等静压机工作缸L形密封结构优化设计

针对温等静压机在200 MPa高压、300℃高温的工作条件下难密封问题,设计由L形金属圈和O形橡胶圈组成的L形密封结构;利用ABAQUS建立L形组合密封结构模型,并利用ABAQUS对该模型进行装配,以及模拟温度及压力载荷等工况,建立密封结构热-力耦合模型,仿真分析得到L形密封结构应力应变分布规律。仿真结果表明:该L形密封结构在低压工况下由O形密封圈起密封作用,在高压工况下,由L形组合密封结构完成密封,因而能满足高温超高压密封要求。针对仿真分析中存在的最大应力值超过材料许用应力的问题,对L形组合密封结构进行优化设计。优化后L形密封结构在高负载工况下的最大应力小于工作缸和端盖的许用应力,接触压力值大于工作压力,能够实现良好密封。     

曲轴复合加工中心主轴箱有限元分析

曲轴复合加工中心是一种高效加工曲轴的新型设备。建立曲轴复合加工中心主轴箱的三维模型,并分析其载荷及边界条件。以ANSYS软件作为分析工具,对曲轴复合加工中心主轴箱进行静力和模态分析,得到了应力云图、位移云图及前七阶模态。由分析可知,主轴箱的最大应力为18.272MPa,应变值为0.0044mm,应力和应变值均较小,固有频率大,动态特性好,满足机床设计要求且具有优化空间,为以后主轴箱结构改进、优化设计和动力修改提供了理论依据。     

利用ANSYS软件对三叉杆滑块式万向联轴器进行应力分析

利用ANSYS有限元分析软件对三叉杆滑块式万向联轴器的三叉槽构件进行应力分析,得出该构件的应力应变分布图,并进行强度校核,为进一步改进三叉杆滑块式万向联轴器的受力情况和结构设计提供了理论依据。     

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...     

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。     

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.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.