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云纹法是一种新的位移场或应变场测试技术,本文采用云纹法论述的遥测自动云纹引伸仪系统包括云纹引伸仪、位移信息转换和传输装置以及显示接收监测台。由于采用了轮形光栅从而使引伸仪突破了传统的测量限制,从理论上讲,量程可达无穷大。 相似文献
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非线性热弹耦合圆板中的混沌带现象 总被引:1,自引:0,他引:1
分析了大挠度圆板在受迫周期激励下的混沌现象,在考虑几何非线性的同时,也计及温度效应的作用,利用Melnikov方法确定动力系统解出现马蹄时参数应满足的条件,研究发现当激励,阻尼及强迫频率之间满足确定关系时,系统将进入混沌状态。 相似文献
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HanQiang(韩强);MaHongwei(马宏伟);ZhangShanyuan(张善元);YangGuitong(杨桂通);WuJike(武际可)(ReceivedNov.18.1994)THEDYNAMICBUCKLINGPROBLEMCAUS... 相似文献
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The paper presents a nonlinear dynamic model of 9 degrees of freedom for four-wheel-steering vehicles. Compared with those
in previous studies, this model includes the pitch and roll of the vehicle body, the motion of 4 wheels in the accelerating
or braking process, the nonlinear coupling of vehicle body and unsprung part, as well as the air drag and wind effect. As
a result, the model can be used for the analysis of various maneuvers of the four-wheel-steering vehicles. In addition, the
previous models can be considered as a special case of this model. The paper gives some case studies for the dynamic performance
of a four-wheel-steering vehicle under step input and saw-tooth input of steering angle applied on the front wheels, respectively.
The project supported by the National Natural Science Foundation of China (59625511) 相似文献
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IntroductionForalongtimetheeffectoftemperatureonthevibrationofplateshasdrawngreatattentioninthefieldofaeronauticsandastronautics,chemistry,nuclearpowerandmechanicalengineering.Incorrespondingtheoreticalanalysisthenonlineareffectshouldbetakenintoconsi… 相似文献
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ntroductionTheelasticorplasticdynamicbucklingofcolumnsundermanykindsofaxialimpactloadinghasbenstudiedforalongtime.Whenstudyin... 相似文献
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In this paper,we study two quasi-one-dimensional(1 D) Kitaev models with ladder-like and tube-like spatial structures,respectively.Our results provide the phase diagrams and explicit expressions of the Majorana zero modes.The topological phase diagrams are obtained by decomposing the topological invariants and the topological conditions for topologically nontrivial phases are given precisely.For systems which belongs to topological class BDI,we obtain the regions in the phase diagrams where the topological numbers show even-odd effect.For the Kitaev tube model a phase factor induced by the magnetic flux in the axial direction of the tube is introduced to alter the classification of the tube Hamiltonian from class BDI to D.The Kitaev tube of class D is characterized by the Z_2 index when the number of chains is odd while 0,1,2 when the number of chains is even.The phase diagrams show periodic behaviors with respect to the magnetic flux.The bulk-boundary correspondence is demonstrated by the observations that the topological conditions for the bulk topological invariant to take nontrivial values are precisely those for the existence of the Majorana zero modes. 相似文献
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三角测量法是一种位移测量方法, 其测量精度不但受到传感器本身因素如光源、探测器、机械结构特性等因素的影响, 还受到被测表面特性如色泽、材料、粗糙度、倾斜度以及外界环境的影响。国内外的一些学者提出了许多提高传感器测量精度的方法, 但这些研究都是针对某一特性表面进行的, 没有涉及到对不同表面的测量时存在的问题。利用随机行走理论对物体表面的散射场进行了分析, 给出了不同粗糙度表面下弱散射光强与散射角及入射角的关系。由于设计制造的传感器量程范围内接收散射光的角度在15°至25°内变化, 因此取20°作为散射角角度, 理论计算模拟的三种不同粗糙面散射光强变化最大能达到300%左右。该结果对于优化激光三角传感器的设计和提高测量精度有一定的意义。 相似文献