共查询到20条相似文献,搜索用时 377 毫秒
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爆炸箔起爆器小尺寸飞片速度测试 总被引:3,自引:0,他引:3
设计了一套爆炸箔起爆装置,通过精确控制桥箔-飞片-加速腔三者的定位,在飞片表面镀一定厚度的铝膜(铝膜的质量与飞片的质量相比可忽略),合理选择VISAR探头的工作距离和与干涉腔延迟时间相关的条纹常数,屏蔽测试系统以及加设滤光片等,利用VISAR测试技术有效解决了小尺寸飞片速度的测试问题。给出了两种尺寸0.7 mm0.025 mm和0.5 mm0.025 mm飞片的速度测试结果。结果表明,采取新的措施后,获得了信噪比好、能正确反映爆炸箔起爆器驱动飞片物理过程的信号和飞片速度历史。 相似文献
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介绍了毫克至克量级弹丸7 km/s以上超高速发射技术的国内外研究进展,并对各发射装置的工作原理和技术要素进行了简要阐述.基于电磁驱动准等熵加载,美国ZR装置驱动25 mm×13mm×1.0mm铝飞片至46km/s速度,国内CQ系列磁驱动加载装置实现了 10mmx6mmx0.33mm铝飞片18 km/s的发射.借助于金属箔电爆炸产生高压气体驱动,美国利弗莫尔实验室100kV电炮装置驱动9.5mm×9.5 mm×0.3 mm的Kapton膜至18 km/s,国内流体物理研究所98 kJ和200 kJ电炮装置分别驱动?10 mmx0.2 mm Mylar飞片和?21 mm×0.5 mm Mylar飞片到10 km/s.基于阻抗梯度飞片技术,采用汇聚型和非汇聚型结构三级轻气炮,实现了厘米量级铝飞片和TC4钛飞片12~15 km/s速度发射.这些超高速驱动技术的发展,为空间碎片防护研究提供了坚实的技术支持. 相似文献
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分析了磁驱动飞片实验和数值计算的研究现状。根据磁驱动实验装置等效电路建立了可带入参数为表达式的电路计算程序。利用建立好的电路计算程序结合LS-DYNA980 MHD计算软件,建立了一种可以耦合电路分析的磁驱动飞片计算方法。采用这种方法模拟了CQ-4的发射飞片实验,计算结果与实验基本符合。最后分析了极板长度h分别为20、25、30 mm并且充电电压73 k V时磁驱动飞片的速度和平面性,认为实验中极板长度取25 mm比较合适。 相似文献
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集成光学角速度传感器系统方案的研究 总被引:6,自引:5,他引:1
本文研究了谐振型和干涉型两类集成光学角速度传器(R- IORS 和I- IORS) 的系统方案,设计了两种R- IORS 的光纤仿真实验装置:反射式和透射式,并介绍了对它们的实验研究结果。文中还提出了一种再入式I- IORS的系统方案,并进行了理论分析。 相似文献
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微光学陀螺仪系统结构的研究 总被引:1,自引:1,他引:1
章燕申 《中国惯性技术学报》2006,14(5):44-46
介绍了谐振型和干涉型两种微光学陀螺仪的分辨率计算公式,并在光纤仿真装置上,分别进行了系统结构的实验研究.在谐振型装置中,作为光源采用了具有 Bragg 光栅的窄线宽激光二极管.在干涉型装置中,为了保证双向光束在Sagnac 效应敏感环 (SSR) 中可以循环传播,采用了大功率的超辐射发光二极管(SLD)作为光源.为了保持双向光束在 SSR 中循环传播多圈,需要在 SSR 中插入一个光放大器,以补偿光束在传播中的各种损耗.研究结果表明,所建议的系统结构对于开发中等精度的微光学陀螺仪产品具有可行性. 相似文献
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Direct determination of curvatures of bent plates using a double-glass-plate shearing interferometer
A single-exposure reflective moiré technique for the direct recording of curvature contours of laterally loaded plates is
proposed. The specular reflection of a coherent, collimated beam of light by the loaded specimen is collected by a field lens
and focussed onto a shearing interferometer. The shearing interferometer consists of two thin, identical plane-parallel glass
plates, placed successively in the optical path near the focal plane and aligned at 45 deg to the optical axis. The two plates
shear the narrow convergent beam from the lens twice optically, producing three sets of images—superposing one over the other—at
the image plane. Curvature fringes result in the region overlapped by all three images. 相似文献
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A novel experimental technique is presented that combines the optical method of caustics and the full-field lateral shearing
interferometer of coherent gradient sensing (CGS) in one setup. Collimated light transmitted through a deformed specimen is
separated into two legs. One is processed by the lateral shearing interferometer and is recombined with the other on a single
image plane. By adjusting the optical path length of each leg, a combination lateral shearing interferogram/caustic image
is generated. When this technique is applied to a fracture specimen, information about the stress intensity factor can be
obtained from the caustic and the CGS interference fringes for exactly the same deformation field. This allows for a direct
comparison between the two methods when investigating phenomena such asK-dominance, three-dimensional deformation and so on. In this paper, the technique is presented in detail, and its feasibility
is tested by application to mode I and mixed-mode crack tip deformation fields. 相似文献
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The special wide-field Michelson interferometer designed at ISL transforms the Doppler frequency shift of light scattered
by tracer particles crossing a light sheet into a shift of luminous intensity at the output of the Michelson interferometer,
yielding information about the particle velocity. To overcome former disadvantages, the optical set-up as well as the Doppler
picture-processing algorithm were further improved. The present status of Doppler picture velocimetry (DPV) is explained by
means of measurements carried out at Mach 6 in the ISL shock tunnel STA. The vertical velocity distribution around several
bodies, such as a wedge, a sphere and a cylinder was visualized and measured. 相似文献
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This paper presents an analysis describing the feasibility of a distributed optical fiber strain sensor whose principle of
operation is based on the frequency-modulated continuous-wave (FMCW) reflectometry technique. The system consists of a frequency-swept
laser diode and an unbalanced two-beam interferometer. In this system, the test arm comprises a number of single-mode fibers,
which act as the sensing fibers, with a mirror at the far end and mechanical splices as the connectors, as well as the reflectors.
Theoretical analysis shows that the measuring resolution of the strain is inversely proportional to the length of the sensing
fiber. The strain variation of the sensing fiber is measured by demodulating the phase shift of the beat signal using a heterodyne
signal processing system, and therefore the requirement of a high precision temperature control of the light source can be
eliminated in this way. The comparison between the theoretical and experimental values of the strain resolution showed excellent
agreement. 相似文献
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Analysis of Speckle Photographs by Subtracting Phase Functions of Digital Fourier Transforms 总被引:1,自引:0,他引:1
K. A. Stetson 《Experimental Mechanics》2013,53(9):1799-1806
This paper presents a method for measuring displacements and strain in digital speckle photography that is an alternative to currently used correlation techniques. The method is analogous to heterodyne speckle photogrammetry wherein optical Fourier transforms were taken of individually recorded specklegrams and combined in a heterodyne interferometer where an electronic phase meter measured the phase differences between the two transforms. Here, digital photographs are recorded and Fourier transformed so that their phase functions can be subtracted and fitted to a linear function of the transform coordinates. The effect of different recording and processing parameters is investigated. It is found that incoherent speckles give better results than those formed by coherent laser light. In addition, image correlation is used to process an identical data set so that comparison of the two methods can be made. 相似文献
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A high-magnification moiré interferometer, particularly suitable for near-tip field analysis in cracked materials, is described.
It has a submillimeter field of view, a high-resolution image sensor (1.4 million pixels), X-Y-Z translation stage and an
optical fiber light delivery system. These features enable the microscope head to observe the crack tip while the specimen
is loaded in a standard tensile test machine. Automated fringe pattern analysis, using temporal phase shifting and spatial
phase unwrapping, enables thex ory displacement component to be measured and the corresponding in-plane strain component computed. The displacement placement
accuracy is better than 40 nm, and the effective strain gage dimension is ∼ 25 μm. Furthermore, the interferometer has a built-in
white light microscope that allows the observation of the specimen granular microstructure in exact registration with the
displacement field. The interferometer has hence been employed to investigate the near-tip fields of a precracked stainless
steel specimen under load. The influence of the grain boundaries on the measured displacement fields was relatively minor.
The near-tip strain field shows a significant asymmetrical behavior despite pure mode lloading conditions. 相似文献