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进行了电解复合超声频振动加工微结构的基础试验,分析了微电流电解过程钝化现象,研究了超声频振动冲击波及负压空化作用消除电解钝化作用机理。分析了电解加工方式与超声频振动协调同步方法,设计和构造了微细电解复合压电式超声频振动微细加工系统。利用微细特种加工技术制作各类截面形状、尺寸的微细阴极。进行了多种材料微结构的复合加工试验,并验证了电解复合超声频振动方法实现微细加工可行性与技术优势,研究了应用该工艺进行微结构加工的工艺特性。 相似文献
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借助ANSYS软件对变幅杆、夹具和工件进行整体的动力学研究,设计了一套超声振动电火花线切割复合加工装置。在相同加工参数下,分别采用工件超声振动电火花线切割复合加工和传统的电火花线切割加工对45钢进行切割试验。试验结果表明:与传统的电火花线切割加工相比,超声振动电火花线切割复合加工的效率提高了约15%,表面粗糙度减小了约10%。 相似文献
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金属橡胶复合叠层耗能器试验研究 总被引:3,自引:0,他引:3
设计了金属橡胶复合叠层耗能器,并进行了试验研究。试验结果表明,复合叠层耗能器的振动特性与振幅和频率有关,是一个具有多种阻尼成分的复杂的非线性迟滞系统,其性能优于橡胶耗能器。试验研究为复合叠层耗能器的优化设计及实际工程应用提供了大量的试验依据。 相似文献
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为了实现动态加速度与时变振动环境的综合模拟,研制了一套适应动态加速度场的轻量宽频激振装置。首先提出了压电-液压串联复合激振方法和装置构型,解决了传统激振方法“宽频不轻量、轻量不宽频”的难题。设计了六单元并联压电激振模块,建立了精密装调工艺,并联激振效率达到74.2%。为满足动态加速度环境下的宽频激振需求,提出液压内嵌式定中方案,研制了具有“缸中缸”构型的液压激振模块。基于分频器,提出了串联复合激振系统的分频控制方法,实现了压电、液压激振模块的协调工作、均衡出力。以力平衡控制结合零位移反馈补偿控制,提出了液压激振模块定中控制方法,实现了动态加速度环境下的精确定中。提出了变增益、长时波形再现两种时变振动控制方法,研制了一体化的控制系统。测试结果表明,串联复合激振装置在离心加速度不低于60 g、加速度变化率不低于15 g/s工况下,分别实现了50 kg负载下的6 grms振动加速度、10~2 000 Hz频率范围的宽频激振。该装置已应用于多项惯性器件、组件和系统的环境试验考核,载荷控制效果良好。相比飞行试验,本文成果为飞行器制导、控制系统功能性能考核提供了高效经济的实验室手段,特别在大样本数... 相似文献
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《振动、测试与诊断》2020,(2)
针对旋转超声钻用于建筑装修时,噪声小而效率偏低的问题,笔者进行了振动钻机构原理创新与试验研究。首先,搭建了高低频复合旋转超声的试验振动样机,可以实现稳定的高低频复合轴向振动钻孔作业;其次,以黏土砖为对象,进行了钻孔效率试验与振动分析,低频振动的引入,虽然使超声锤击工件表面的时间缩短了80%,但在进给力基本不变的条件下,钻孔速度提高了一倍左右,噪声仍可控制在60dB(A);最后,结合振动特性分析可以推断,在高低频复合振动钻孔过程中,超声振动主要负责对脆性材料的破碎作业,而低频振动主要负责将破碎后形成的颗粒快速离开切削区,从而提高钻进速度。因此,高低频复合振动钻进新原理,可以发挥高频振动与低频振动的优势,有望发展为一类新型钻孔装备。 相似文献
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《Measurement》2016
When a hypersonic aircraft flies at a high Mach number, the plate-like attitude control structures, such as the wings and rudders, will be exposed to an extremely high-temperature environment. To obtain the thermal modal parameters of a structure that are difficult to measure, a high-temperature transient heating test system and a vibration test system were combined to establish a test system that can perform the thermal/vibration test at 1200 °C. Infrared radiation heating was employed to generate a controlled time-varying high-temperature environment, and an exciter was used to exert vibration excitation on the free end of the cantilever rectangular plate. A self-developed extension configuration of a high-temperature-resistant ceramic pole was used to transfer the vibration signals of the structure to a non-high temperature zone, and the acceleration sensors were applied to identify the vibration signals. The test data were analyzed using a time-frequency joint analysis technique, and next, the key vibration characteristic parameters of structure in a thermal-vibration coupled environment up to 1200 °C (e.g., the modal frequency and modal vibration shape) were experimentally obtained. In addition, the numerical simulation on the thermal modal characteristics of a rectangular plate was performed. The calculated results coincide favorably with the test results, verifying the credibility and effectiveness of the experimental methods. The research results can provide an important basis for the dynamic performance analysis and safety design of structure under high-temperature thermal-vibration conditions for hypersonic flight vehicles. 相似文献
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Noroozi Z Kido H Peytavi R Nakajima-Sasaki R Jasinskas A Micic M Felgner PL Madou MJ 《The Review of scientific instruments》2011,82(6):064303
A novel, centrifugal disk-based micro-total analysis system (μTAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude. 相似文献
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Yuichi Murai Kazumasa Inaba Yasushi Takeda Fujio Yamamoto 《Flow Measurement and Instrumentation》2007,18(5-6):223-229
Backlight imaging tomography is used to experimentally investigate interfacial structures of gas–liquid two-phase flow in circular tubes. The tomography method is based on the attenuation of visible light that causes the inside of the liquid phases to be colored with dye. Increasing the number of light projections provides accurate phase distributions to be reconstructed by a linear backward projection scheme. After the reconstruction performance is examined with numerical simulations for several test cases, the method is applied to slug flows that have complicated 3D interfaces from turbulence. Interfacial structures are compared between straight and helical tubes to determine the effect of centrifugal acceleration. The result demonstrates that centrifugal acceleration provides a liquid-clinging layer on the inner wall against gravity while a high-speed collision of liquid with the top wall happens in a straight tube. 相似文献
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高空下降物体的重力加速度会使旋转的电机转轴盘随之旋转产生离心力。正确利用离心力,可以使高空下降的物体达到设计的匀速下降速度。 相似文献
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A centrifugal impact-test bench with a inertial-pulsed mechanism, in which the supporting table undergoes curvilinear translation,
is compared with transmission and rotation test benches. The parameters of this bench and the acceleration pulse are calculated.
The inertial-pulsed mechanism permits the accommodation of large samples on the table; ensures a uniform acceleration field
on the table and at the tested product; and permits the reproduction of high acceleration over long periods of action. 相似文献