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51.
In order to improve the explosion characteristics of emulsion explosives, titanium hydride was added to emulsion explosives to produce a new type of hydrogen storage emulsion explosives. Charges with different contents of titanium hydride were evaluated through underwater explosion experiments and detonation velocity tests. The tests on underwater explosion and detonation velocity reveal that compared to pure emulsion explosives, the detonation parameters of emulsion explosives containing titanium hydride showed a trend of first increasing and then decreasing. When the mass ratio of titanium hydride in the emulsion explosive is 1 % to 3 %, all detonation parameters have been improved to a certain extent. When the mass ratio of titanium hydride in the emulsion explosive is 3 % to 10 %, only part of the detonation parameters (specific impulse, specific shock energy, specific total energy and volume energy density) has been improved. The maximum increase of specific impulse, specific shock energy, specific total energy and volume energy density of emulsion explosive containing titanium hydride is 7.06 %, 8.95 %, 3.97 % and 8.22 %, respectively. Based on the analysis, it is evident that though powdered TiH2 participates in the detonation reaction process of the emulsion explosive, the majority of TiH2′s energy is released during the secondary reaction occurring after the detonation wave front. Therefore, the detonation performance of emulsion explosives can be effectively improved by adding a certain mass ratio of titanium hydride. 相似文献
52.
针对机载电子设备结构形式复杂、零件尺寸不大、批量较小、种类较多及漆种较多的特点,设计了一种高柔性多品种小批量的全自动机器人喷涂生产线。该生产线采用基于Profibus工业总线的控制技术,实现整个喷涂生产线系统的通信和组网。采用射频识别技术进行零件喷涂工艺信息的识别。采用基于UG模型的全数字化喷涂程序设计及喷涂仿真技术进行零件喷涂程序的设计、喷涂工艺的优化。 相似文献
53.
54.
焊接压力容器的机器人工作站 总被引：1，自引：0，他引：1
论述了一个弧焊机器人工作站在压力容器焊接生产中的应用情况,介绍了其系统配置,产品结构特点,工艺特点,程序编制等要素,并对焊接编程的优化和一些常见问题的解决方法进行了探讨。 相似文献
55.
56.
碰撞是仿人机器人研究的难点.今设计了5自由度仿人机器人上肢体,并且基于雅克比矩阵建立了速度运动学模型;基于拉格朗日能量函数法,建立了动力学模型;采用广义非线性等效弹簧阻尼模型,建立了碰撞动力学模型.参照人体特性,搭建了ADAMS虚拟样机仿真平台,进行了上肢体击掌动作仿真实验,开展了不同刚度系数值下的手部接触碰撞仿真.实验曲线表明动作仿人,角速度曲线满足正弦曲线形态;碰撞中,肘关节所受力矩最大;缓冲后,腕关节所受力矩大于肘关节.证明碰撞仿真平台有效,碰撞时应采用较小的仿真步长. 相似文献
57.
Selection of electrode for GTA‐Underwater Welding Reproducible good weld quality and economical benefit of underwater‐welding require a complete automation. For this purpose Gas Tungsten Arc‐welding (GTA or TIG) offers numerous advantages, especially for the root and the following hot pass run. Disadvantages of GTA‐welding are the low weld deposit rate and the limited lifetime of the tungsten electrode. Already small wear damages cause wide alterations of the arc under high surrounding pressure, so that a suited choice of the electrode enables to increase the productivity considerably. Therefore the influence of the electrode features on welding process, arc stability, arc ignition, weld geometry and electrode wear has been investigated. For quick and elementary selection of electrode an assessment catalogue was elaborated. 相似文献
58.
M. A. Sprague T. L. Geers 《International journal for numerical methods in engineering》2004,60(15):2467-2499
In an underwater‐shock environment, cavitation (boiling) occurs as a result of reflection of the shock wave from the free surface and/or wetted structure causing the pressure in the water to fall below its vapour pressure. If the explosion is sufficiently distant from the structure, the motion of the fluid surrounding the structure may be assumed small, which allows linearization of the governing fluid equations. In 1984, Felippa and DeRuntz developed the cavitating acoustic finite‐element (CAFE) method for modelling this phenomenon. While their approach is robust, it is too expensive for realistic 3D simulations. In the work reported here, the efficiency and flexibility of the CAFE approach has been substantially improved by: (i) separating the total field into equilibrium, incident, and scattered components, (ii) replacing the bilinear CAFE basis functions with high‐order Legendre‐polynomial basis functions, which produces a cavitating acoustic spectral element (CASE) formulation, (iii) employing a simple, non‐conformal coupling method for the structure and fluid finite‐element models, and (iv) introducing structure–fluid time‐step subcycling. Field separation provides flexibility, as it admits non‐acoustic incident fields that propagate without numerical dispersion. The use of CASE affords a significant reduction in the number of fluid degrees of freedom required to reach a given level of accuracy. The combined use of subcycling and non‐conformal coupling affords order‐of‐magnitude savings in computational effort. These benefits are illustrated with 1D and 3D canonical underwatershock problems. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
59.
The aim of this applied research project is a cleaning robot which automatically cleans the outside of windows on a facade with vertical jambs and horizontal bars. The facade has to possess certain constructive properties. This “interface” enables the cleaning robot — which is detachable from the building and portable — to operate on any respectively designed facade on several buildings. A special cleaning-head keeps the water used for cleaning in a constant cycle. It is wielded through a filter and reused. The cleaning robot in operation is quicker, safer and cheaper than manual cleaning. Its use is environment-friendly and considerate with regard to resources. 相似文献
60.
水下绞车是进行海洋环境监测和立体剖面测量的重要设备,介绍了水下绞车的国内外发展现状,提供了一种无人值守式水下绞车装置的结构及相关参数计算。 相似文献