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本文基于光学和扫描显微平台,介绍了本研究组在微尺度实验力学检测技术和设备方面的最新研究成果。在检测技术方面涉及显微散斑干涉技术、微标记阵列检测技术、晶粒变形分析技术、光学探针动静态变形分析技术;在检测系统和装置方面介绍了新近开发的双视场薄膜检测系统、散斑微干涉系统、微标记检测平台、AFM和SEM单轴拉伸装置、三维微定位与加载系统、微力传感器及其标定装置、微动平台驱动装置等。探讨了微尺度实验力学检测中的问题和新的检测技术,给出了一些典型的应用和相关装置。 相似文献
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随着集成电路芯片、传感器、柔性电路系统、微/纳机电系统等微机械装置向集成化和小型化不断发展,如何预测其内部微纳米尺度结构和材料的机械性能及其可靠性成为了制约上述微机械装置进一步发展和应用的关键问题之一。在这些装置的长期使役过程中,微纳米尺度材料的疲劳性能又成为了近年来人们关注的热点问题。针对上述问题,首先,调研了与微纳米尺度材料原位疲劳实验方法和疲劳性能研究有关的文献。然后,总结了微纳米尺度原位疲劳实验方法和疲劳性能的研究现状,包括含有孪晶组织金属、梯度组织或粗细晶金属以及在单轴、多轴应力状态下的金属疲劳性能研究,并归纳了微纳米尺度界面疲劳损伤行为的研究现状。最后,对微纳米尺度材料的疲劳性能研究进行了展望,提出了对未来发展方向的思考。 相似文献
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研制了一套可应用于MEMS器件的微尺度测量系统,可以在受载状态下实时检测MEMS器件的面内位移、离面位移和三维形貌。该系统中,面内位移测量是一个基于白光数字散斑相关方法的显微光学测量系统,与相应的力学加载系统结合,可以得到MEMS器件在受载状态下的实时面内位移;离面位移和三维形貌测量则是一个基于相移显微投影光栅方法的光学测量系统,与相应的力学加载系统结合,可以得到MEMS器件在受载状态下的实时三维形貌和离面位移。最后给出了几个典型的MEMS器件面内位移、离面位移和三维形貌的实测结果。 相似文献
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《Acta Mechanica Solida Sinica》2015,(4)
Based on the negative exponential pair-potential(1/R)n, the interaction potential between the micro/nano planar curve and the particle located outside the curve is studied. We verified that, whatever the value of exponent n may be, the potential of particle/plane-curve is always of unified curvature form. Furthermore, we proved that the driving forces acted on the particle may be induced by the highly curved micro/nano curve, and the curvature and gradient of curvature are confirmed to be the essential factors forming the driving force. Through the idealized numerical experiments, the accuracy and reliability of the curvature-based potential are examined. 相似文献
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Recent experiments and molecule dynamics simulations have shown that adhesion droplets on conical surfaces may move spontaneously
and directionally. Besides, this spontaneous and directional motion is independent of the hydrophilicity and hydrophobicity
of the conical surfaces. Aimed at this important phenomenon, a general theoretical explanation is provided from the viewpoint
of the geometrization of micro/nano mechanics on curved surfaces. In the extrinsic mechanics on micro/nano soft curved surfaces,
we disclose that the curvatures and their extrinsic gradients form the driving forces on the curved spaces. This paper focuses
on the intrinsic mechanics on micro/nano hard curved surfaces and the experiment on the spontaneous and directional motion.
Based on the pair potentials of particles, the interactions between an isolated particle and a micro/nano hard curved surface
are studied, and the geometric foundation for the interactions between the particle and the hard curved surface is analyzed.
The following results are derived: (a) Whatever the exponents in the pair potentials may be, the potential of the particle/hard
curved surface is always of the unified curvature form, i.e., the potential is always a unified function of the mean curvature
and the Gaussian curvature of the curved surface. (b) On the basis of the curvature-based potential, the geometrization of
the micro/nano mechanics on hard curved surfaces may be realized. (c) Similar to the extrinsic mechanics on micro/nano soft
curved surfaces, in the intrinsic mechanics on micro/nano hard curved surfaces, the curvatures and their intrinsic gradients
form the driving forces on the curved spaces. In other words, either on soft curved surfaces or hard curved surfaces and either
in the extrinsic mechanics or the intrinsic mechanics, the curvatures and their gradients are all essential factors for the
driving forces on the curved spaces. (d) The direction of the driving force induced by the hard curved surface is independent
of the hydrophilicity and hydrophobicity of the curved surface, explaining the experimental phenomenon of the spontaneous
and directional motion. 相似文献
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In this review, acritical look at the research progress ofexperimentalsolid mechanics in China for the past years is presented. Issues are discussed of the discovery and development of new fundamental methods and techniques versus performance benchmarking for many of their applications. Included herein are photoelasticity and various forms of modern photomechanics, acoustical techniques, image processing and videometrics, radial and spectrum techniques, and experimental mechanics on micro/nano scale. It is also noticed that both the ever developed instrumentation and specialized synthetical techniques have played important roles in advancing experimental mechanics in scientific researches and industrial applications. Finally, an attempt is made to look into the future of experimental solid mechanics with personal opinions offered on what the future trends will be for the researches in the field. 相似文献
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表面能对纳米颗粒的晶格收缩和固有频率的影响 总被引:6,自引:0,他引:6
由于纳米颗粒具有很大的比表面积,因此,表面能对它的力学性能有着不可忽略的影响.本文给出了由表面能所导致的纳米颗粒晶格收缩效应的解析结果,与试验观察定量上相当一致;计算了表面能对纳米颗粒固有频率的影响,预测了由于表面能的影响,纳米颗粒出现的“振动软化”现象. 相似文献
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Liang Liu Dujuan Zeng Xianlong Wei Qing Chen Xide Li 《Acta Mechanica Solida Sinica》2009,22(6):584-592
Two kinds of clamping in micro/nano scale experiments are investigated in this paper, one based on electron-beam-induced deposition, and the other on the van der Waals interaction. The clamping strength and mechanism are analyzed both theoretically and experimentally. The influence of relative humidity on the micro/nano clamping and the method of electrostatic clamping are discussed. The clamping strength and performance of different clamping methods are compared considering the size and material of the clamped objects, and the application environments. 相似文献
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煤炭是我国的主体能源,煤矿井下冲击地压、煤与瓦斯突出等灾害的频繁严重影响煤炭的安全生产.煤体是典型的混合物,其内部不同组分的力学性质差异较大,使其在外部扰动的作用下容易产生内部应力集中,导致煤体的失稳、破坏,形成煤矿动力灾害.本文以非均质煤体为研究对象,利用微焦CT、扫描电子显微镜和纳-微米压入实验,研究了煤体微纳尺度的非均质结构和力学性质,实验研究结果表明:煤体是有机物和多种矿物组成的混合物,矿物以点填充、丝状填充和条带状侵入等结构存在于煤体有机物中,不同的矿物填充或侵入区域中矿物含量和结构具有差异,这导致煤体微纳尺度的物理力学性质具有非均质性;纳米尺度压入实验可以捕捉矿物在有机物中的填充或侵入结构,测量煤体混合物中矿物和有机物单组分的力学参数,识别两者力学性质的巨大差异;微米尺度的压入实验可以表征煤体混合物整体的力学性质,矿物填充量越多,煤体混合物的力学性质越强,同时煤体混合物微观尺度的破裂模式会受到矿物填充结构的影响.研究结果揭示了煤体微观结构和力学性质的非均质特征,探讨了煤体混合物的非均质结构可能引起的脆性破坏,为煤矿井下冲击地压和煤与瓦斯突出等动力灾害的预测与防治提供了理论基... 相似文献
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The nonlinear dynamic and static deflection of a micro/nano gyroscope under DC voltages and base rotation are investigated. The gyroscope undertakes two cou- pled bending motions along the drive and sense directions and subjected to electrostatic actuations and intermolecular forces. The nonlinear governing equations of motion for the system with the effect of electrostatic force, intermolecular tractions and base rotation are derived using extended Hamilton principle. Under constant voltage, the gyroscope finds the preformed shape. First, the deflection of the rnicro/nano gyroscope under electrostatic forces is obtained by static and dynamic analyses. Furthermore, the static and dynamic in- stability of the system are investigated. Afterward the oscillatory behavior of the pre-deformed micro/nano gyroscope around equilibrium is studied. The effects of intermolecular and nonlinear parameters on the static and dynamic de- flection, natural frequencies and instability of the micro/nano gyroscope are studied. The presented model can be used to exactly determine static and the dynamic behavior of vibratory micro/nano gyroscopes. 相似文献
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A new method for enhancing the heating effect of high power short pulse laser on biological tissue by micro/nano metal particles
was proposed. Theoretical analysis of the influences of the micro/nano particle kind, the concentration and the microcosmic
distribution of micro/nano particles on the temperature response was carried out with a multi-layer hyperbolic heat conduction
model with volumetric heat generation. The results indicate that embedding micro/nano particles could improve the surface
temperature increase of biological tissue with short duration and reduce the deeper material temperature under the same heating
condition, which would help strengthen the heating effects of high power short pulse laser on biological tissue. This study
may open a new technical approach for improving laser applications. 相似文献
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21世纪信息技术、微纳米技术和生物技术等新兴领域的高速发展给力学专业的人才培养带来了机遇与挑战。本文简单介绍了高等教育的基本理念与发展及其在中国的演变。通过分析现阶段社会发展的需求和力学发展的趋势,阐述了力学本科的培养目标应该是具有宽广的人文素养和深厚的专业知识的创新型人才。本文结合上海大学二十余年来理论与应用力学本科人才培养的实际情况,对实现这一目标提出了几点参考建议。 相似文献