共查询到20条相似文献,搜索用时 171 毫秒
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受迫振动与共振实验是高中物理重要内容,是教学难点.利用可调速的直线电机提供更稳定的驱动力,通过光电门传感器采集驱动频率;设计位移传感器的发射端做为振子,观察受迫振动与共振现象,并实时采集振子的位移与时间图像,通过图像处理获取振子振动的频率和振幅值,采集多组数据,定量探究振子振动的频率与驱动频率的关系,绘制共振曲线,得到... 相似文献
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利用磁耦合双光栅法动态测量了材料的弹性模量,采用电磁能非接触耦合样品激振,激光光拍法微振动非接触检测,使测试样品处于完全自由振动状态,通过激光光拍微弱振动位移测量了样品的固有频率,再通过测量几何尺寸和质量即可计算出样品的弹性模量. 相似文献
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本文系统地研究了动力学法测量杨氏模量的实验原理,结果表明实验测得的频率是金属棒与换能器组成的系统的固有频率,并得到该频率的基本公式.结果还证实由外推法处理后的频率的确是金属棒的固有频率. 相似文献
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The aim of this paper is to study the longitudinal frequency of a cracked nanobeam. The frequency equation of the nanobeam with clamped–clamped and clamped–free boundary conditions is derived based on the nonlocal elasticity theory. According to the equation, it can be found that the effects of the crack parameter, crack location, and nonlocal parameter on the longitudinal frequency of the cracked nanobeam are significant. The frequency decreases with an increase of the crack parameter. However, the increasing nonlocal parameter results in a decrease of the crack effect on the frequency. In addition, when the crack location is near the support, a larger decrease in the frequency can be observed. 相似文献
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“舌簧片振动法”测杨氏模量 总被引:5,自引:0,他引:5
对材料的杨氏模量的测定历来是研究材料的力学性质以及结构的重要手段,因此,实验科学工作者在不断地探索用各种不同的实验方法来测量材料的杨氏模量,本文介绍国外(日本)常用的一种测量的方法-舌簧片振动法。 相似文献
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关于受迫振动、共振的实验研究 总被引:1,自引:2,他引:1
简要分析了现行中学物理课本中关于受迫振动和共振的演示实验中存在的缺点,并针对其不足加以改进.改进后的实验装置演示效果更好,便于学生理解和掌握相应的物理规律. 相似文献
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The size-dependent elastic property of rectangular nanobeams (nanowires or nanoplates) induced by the surface elas- ticity effect is investigated by using a developed modified core-shell model. The effect of surface elasticity on the elastic modulus of nanobeams can be characterized by two surface related parameters, i.e., inhomogeneous degree constant and surface layer thickness. The analytical results show that the elastic modulus of the rectangular nanobeam exhibits a distinct size effect when its characteristic size reduces below 1 O0 nm. It is also found that the theoretical results calculated by a mod- ified core-shell model have more obvious advantages than those by other models (core-shell model and core-surface model) by comparing them with relevant experimental measurements and computational results, especially when the dimensions of nanostructures reduce to a few tens of nanometers. 相似文献
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W. Koechner 《Applied Physics A: Materials Science & Processing》1973,2(5):279-280
A method for determining the rupture stress and modulus of elasticity of Nd:YAG crystals is described, and measurements are
given for various kinds of surface finish. 相似文献
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根据压电陶瓷晶体压电原理、压电陶瓷棒和试样横振动原理,分析了动态杨氏模量实验中出现的多个谐振频率,理论分析与实验结果吻合. 相似文献
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This Letter aims at the investigation of free-vibration properties of nanocones based on a nonlocal continuum shell model. A novel approach is used for derivation of the governing equations of motion and the Galerkin technique is used to obtain the natural frequencies of vibrations. The effects of small-scale and geometrical parameters of the nanocone on the natural frequencies are studied and some conclusions are drawn. 相似文献