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本文介绍一种自行研制的高速摄影胶片的自动分析系统。记录物体冲击,爆炸或高速运动的胶片通过可定画幅控制的胶片传送机构,由摄像机将图像转化成电信号,并存储在数字图像2处理系统中,通过乍分析软件对特征点进行提取和相关匹配分析,可确定运动物体上各种特征占的运动变化。同时该系统还具备消除摄影像系统畸变影响的功能,确保数据处理的精度。 相似文献
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本文叙述了龙首山大爆破中,利用高速摄影方法所测得的鼓包运动的许多重要现象,如鼓包运动的速度和时间的关系;爆破发展过程中裂缝的出现和发展等等。同时还据此分析了鼓包运动中的若干问题。 相似文献
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均匀来流条件下并行排列旗帜耦合运动模式的实验 总被引:2,自引:1,他引:1
利用高速摄影技术在低速风洞中记录了不同间距并行排列的两个旗帜在不同来流速度中的耦合运动。利用自编的时间-空间演化图像处理软件分析总结了旗帜的耦合运动模式以及旗帜摆动振幅、频率和St数的变化规律。实验结果显示,随着排列间距和来流速度的变化,两旗帜可能以静止、同向摆动、反向摆动和过渡状态这四种不同的模态耦合运动。两旗帜同向摆动时摆动频率明显低于单个旗帜在相同来流中的值,反向摆动时情况相反。在过渡状态中两旗帜摆动的振幅交替增减并且运动中同时包含有两个频率,而同向和反向摆动都是单频率的运动。 相似文献
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中国光学学会高速摄影与光子学专业委员会委托西南流体物理研究所承办高速摄影技术培训班,时间拟定于1984年7月中旬至8月中旬。 在培训期间,主要通过讲课和实验使学员掌握高速摄影的各种测试方法,包括高速相机的原理及操作技术、暗室技术、图象处理技术、脉冲X光摄影技术、全息摄影技术、国内外高速摄影文献资料检索方法等内容。教员由长期从事高速摄影技术的科研人员担任。培训对象主要为从事爆炸专 相似文献
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风沙颗粒运动的数字高速摄影图像的分割算法 总被引:2,自引:0,他引:2
为了深入理解多因素驱动下风沙颗粒起动的动态演化规律, 需要准确地获得沙质床面附近沙粒群起跳的方式、速度和运动轨迹. 以连续强激光源为照明的数字高速摄影技术是研究这类问题的有效手段, 但由于风沙运动的高速摄影图像具有运动沙粒和静止床面的对比度小、相邻两帧图像相似性小等特点, 原始图像叠加算法难以有效实现目标与背景的分割. 该文提出了基于相邻的风沙运动图像灰度差值变化原理的图像分割算法. 实例显示,只要选择合适的相邻图像灰度差值阈值和自适应二值化处理方法就能实现图像中运动沙粒与床面分割. 当起跳沙粒浓度较低情况下, 基于MATLAB平台的最小距离匹配的粒子追踪算法(PTV算法)能较为准确地恢复床面附近沙粒的运动轨迹. 相似文献
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《Acta Mechanica Sinica》2014,(6)
正http://www.icfm7.org First Announcement and Call for PapersThe objective of International Conference on Fluid Mechanics(ICFM)is to provide a forum for researchers to exchange new ideas and recent advances in the fields of theoretical,experimental,computational Fluid Mechanics as well as interdisciplinary subjects.It was successfully convened by the Chinese Society of Theoretical and Applied Mechanics(CSTAM)in Beijing(1987, 相似文献
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《Acta Mechanica Solida Sinica》2014,(5):F0003-F0003
Contributions: The Journal, Acta Mechanica Solida Sinica, is pleased to receive papers from engineers and scientists working in various aspects of solid mechanics. All contributions are subject to critical review prior to acceptance and publication. 相似文献
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Yulong Ding Qingshan Zhu 《中国颗粒学报》2008,6(1):1-1
This special issue of PARTICUOLOGY is devoted to the first UK-China Particle Technology Forum taking place in Leeds, UK, on 1-3 April 2007. The forum was initiated by a number of UK and Chinese leading academics and organised by the University of Leeds in collaboration with Chinese Society of Particuology, Particle Technology Subject Group (PTSG) of the Institution of Chemical Engineers (IChemE), Particle Characterisation Interest Group (PCIG) of the Royal Society of Chemistry (RSC) and International Fine Particle Research Institute (IFPRI). The forum was supported financially by the Engineering and Physics Sciences Research Council (EPSRC) of United Kingdom, 相似文献
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针对捷联导引头无法直接获取视线角速度等信息的问题,研究了鲁棒滤波在大气层外飞行器捷联导引头视线角速度估计中的应用。为了建立非线性滤波估计模型,考虑目标视线角速度的慢变特性,采用一阶马尔科夫模型建立了状态方程;推导了视线角速度的解耦模型,并建立了量测方程;考虑到实际应用中存在系统噪声统计特性失准的问题,基于Huber-Based鲁棒滤波方法,设计了视线角速度滤波器,并完成了基于Huber-Based滤波方法和扩展卡尔曼滤波方法的数学仿真。仿真结果表明Huber-Based滤波方法的视线角、视线角速度及视线角加速度估计精度分别达到0.1140'、0.1423'/s、0.0203'/s2,而扩展卡尔曼滤波方法的视线角、视线角速度及视线角加速度估计精度仅分别为0.6577'、0.6415'/s、0.0979'/s~2。仿真结果证明了该方法可以有效地估计出相对视线角速度等信息,并且在非高斯噪声的条件下,依然可获得较高的估计精度,具有一定的鲁棒性。 相似文献
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《Acta Mechanica Sinica》2014,(3):F0003-F0003
正Each of the sections below provides essential information for authors.We recommend that you take the time to read them before submitting a contribution to Acta Mechanica Sinica.We hope our guide to authors may help you navigate to the appropriate section.How to prepare a submission This document provides an outline of the editorial process involved in publishing a scientific paper in Acta Mechanica 相似文献
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G.C. Sih 《Theoretical and Applied Fracture Mechanics》2010,53(2):94-112
Multiscale material intends to enhance the strength and life of mechanical systems by matching the transmitted spatiotemporal energy distribution to the constituents at the different scale, say—macro, micro, nano, and pico,—, depending on the needs. Lower scale entities are, particularly, critical to small size systems. Large structures are less sensitive to microscopic effects. Scale shifting laws will be developed for relating test data from nano-, micro-, and macro-specimens. The benefit of reinforcement at the lower scale constituents needs to be justified at the macroscopic scale. Filling the void and space in regions of high energy density is considered.Material inhomogeneity interacts with specimen size. Their combined effect is non-equilibrium. Energy exchange between the environment and specimen becomes increasingly more significant as the specimen size is reduced. Perturbation of the operational conditions can further aggravate the situation. Scale transitional functions and/or fj/j+1 are introduced to quantify these characteristics. They are represented, respectively, by , and (fmi/ma,fna/mi,fpi/na). The abbreviations pi, na, mi, and ma refer to pico, nano, micro and macro.Local damage is assumed to initiate at a small scale, grows to a larger scale, and terminate at an even larger scale. The mechanism of energy absorption and dissipation will be introduced to develop a consistent book keeping system. Compaction of mass density for constituents of size 10−12, 10−9, 10−6, 10−3 m, will be considered. Energy dissipation at all scales must be accounted for. Dissipations at the smaller scale must not only be included but they must abide by the same physical and mathematical interpretation, in order to avoid inconsistencies when making connections with those at the larger scale where dissipations are eminent.Three fundamental Problems I, II, and III are stated. They correspond to the commonly used service conditions. Reference is made to a Representative Tip (RT), the location where energy absorption and dissipation takes place. The RT can be a crack tip or a particle. At the larger size scales, RT can refer to a region. Scale shifting of results from the very small to the very large is needed to identify the benefit of using multiscale materials. 相似文献