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Chunlei Wang Konghui Guo Jiming Lv Yi Yang 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(11):1538-1553
Scissor seat suspension has been applied widely to attenuate the cab vibrations of commercial vehicles, while its design generally needs a trade-off between the seat acceleration and suspension travel, which creates a typical optimisation issue. A complexity for this issue is that the optimal dynamics parameters are not easy to approach solutions fast and unequivocally. Hence, the hierarchical optimisation on scissor seat suspension characteristic and structure is proposed, providing a top-down methodology with the globally optimal and fast convergent solutions to compromise these design contradictions. In details, a characteristic-oriented non-parametric dynamics model of the scissor seat suspension is formulated firstly via databases, describing its vertical dynamics accurately. Then, the ideal vertical stiffness-damping characteristic is cascaded via the characteristic-oriented model, and the structure parameters are optimised in accordance with a structure-oriented multi-body dynamics model of the scissor seat suspension. Eventually, the seat effective amplitude transmissibility factor, suspension travel and the CPU time for solving are evaluated. The results show the seat suspension performance and convergent speed of the globally optimal solutions are improved well. Hence, the proposed hierarchical optimisation methodology regarding characteristic and structure of the scissor seat suspension is promising for its virtual development. 相似文献
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Wenjun Ding Baowei Song Zhaoyong Mao Keyan Wang 《Journal of Marine Science and Technology》2016,21(2):359-367
In the interest of extending the operation time of underwater mooring platforms, it is promising and feasible to harvest energy from ocean. A low frequency horizontal pendulum ocean kinetic energy harvester for underwater mooring platforms was presented in this paper. Several series of experimental tests on energy harvesting were carried out. The present research investigates the influence of parameters including excitation frequency, excitation amplitude, inertia modification (ballasting) and pendulum rod length, on the energy harvesting performance. Results show that this type of horizontal pendulum energy harvester has the best performance at resonant frequencies 0.2, 0.25 and 0.3 Hz, with the pendulum pitch angle 3°, 4° and 5°, respectively. It is indicated that the energy harvester can slightly tune the natural frequency to meet the prominent excitation frequency through varying the pendulum pitch angle. The test results also show that the optimal output power take off damping is 30 or 40 Ω in most case, and the maximum average output power can reach 0.3 W, with high normalized power density of 3453.8 kg/m3. Similarly, the results show that three parameters, excitation amplitude, inertia modification (ballasting), and pendulum rod length, have a significant influence on the energy harvesting. This work constitutes a preliminary step towards the development of a low frequency horizontal pendulum ocean kinetic energy harvester for underwater mooring platforms. 相似文献
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水面舰艇电子战系统改进项目是美海军对作战舰艇上的舰载AN/SLQ-32(V)电子战系统进行螺旋式开发升级和替代的项目。通过分析水面舰艇电子战系统面临的新威胁,以及改进项目四个具体阶段采用的技术,得出改进后美海军水面舰艇电子战系统应对威胁的新能力。 相似文献
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对于摩托车减震器底筒受潮后锈蚀,一般都认为是涂装工艺过程不合理或涂料选择不当引起的。经过无数次反复的试验后发现,底筒受潮锈蚀与铝合金材料夹杂物及铸造工艺控制有直接关系。 相似文献
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