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排序方式: 共有1743条查询结果,搜索用时 15 毫秒
941.
Xiaodong Hu Chunguang Hu Zhi Chen Tong Guo Xiaotang Hu 《Optics & Laser Technology》2007,39(6):1176-1182
A stroboscopic Mirau microscopic interferometer system for measuring in-plane and out-of-plane periodic motions of microstructures is demonstrated. One full cycle of a periodic motion is divided into a number of motion phases. One sequence of interferograms with different phase shifting steps is collected at every motion phase by using stroboscopic imaging. A bright-field image can be extracted from one sequence of interferograms with the same motion phase. In-plane displacements are measured by applying an image matching method to all bright-field images, followed by a compensation for the relative positions of interferograms at the different motion phases, before calculating the phase distribution related to out-of-plane deformation. We demonstrate its capability for measuring a combination of out-of-plane deformation and in-plane displacement in a microresonator. 相似文献
942.
I. M. Dementjev I. A. Kamalov P. I. Kovalev V. A. Komissaruk A. N. Mikhalev S. G. Tomson 《Optics & Laser Technology》1987,19(6):316-318
A grating interferometer is described, with a 200 mm working field, assembled on the base of a shadow device. Results are presented for the testing of the interferometer in ballistic experiments. 相似文献
943.
H. Delbarre C. Przygodzki M. Tassou D. Boucher 《International Journal of Infrared and Millimeter Waves》2000,21(6):883-894
High precision index measurements (n/n 10-5) have been recently achieved on an AgGaS2 crystal using a spectral interferometry technique with a polarized white-light continuum. Up to now, these measurements are limited to the visible and near-infrared range, the most dispersive domain. We investigate the possibility to extend the technique to far infrared index measurements. We demonstrate a criterion depending only on group velocity dispersion and crystal thickness for planning future experiments. 相似文献
944.
动态光力学多种测试方法研究及其进展 总被引:5,自引:0,他引:5
本文提出了多种动态光力学方法,还介绍一种瞬态图象的采集技术,并将其应用到动态电子散斑(DESPI)的测试方法中 相似文献
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948.
In this paper we present an experimental procedure for the elastic characterization of thin anisotropic plates. The procedure allows the determination of the elastic constants of isotropic materials (metals and ceramics) and orthotropic materials (composite laminae). Moreover, the flexural compliances of completely anisotropic uncoupled materials (most of composite laminates) can also be measured. The tests are carried out by applying a concentrated force to the specimen supported by three spheres. The stress components are evaluated by simply measuring the applied load, while the strain fields are measured by digital phase-shifting speckle interferometry. The experimental procedure is entirely controlled by a virtual instrument developed for this purpose in the National Instruments LabVIEW® environment, which runs on a personal computer interfaced with a standard black and white CCD camera. By means of the speckle interferometer, the whole field of the out-of-plane displacements is acquired; the curvatures, and hence the strain components, are obtained by two subsequent numerical differentiations. The numerical processing of the experimental data was carried out in the Mathematica? environment. The results obtained on a steel specimen and on a composite laminate are reported. 相似文献
949.
Failure behavior of composite materials in general and particulate composites in particular is intimately linked to interactions
between a matrix crack and a second phase inclusion. In this work, surface deformations are optically mapped in the vicinity
of a crack–inclusion pair using moiré interferometry. Edge cracked epoxy beams, each with a symmetrically positioned cylindrical
glass inclusion ahead of the tip, are used to simulate a compliant matrix crack interacting with a stiff inclusion. Processes
involving microelectronic fabrication techniques are developed for creating linear gratings in the crack–inclusion vicinity.
The debond evolution between the inclusion–matrix pair is successfully mapped by recording crack opening displacements under
quasi-static loading conditions. The surface deformations are analyzed to study evolution of strain fields due to crack–inclusion
interactions. A numerical model based on experimental observations is also developed to simulate debonding of the inclusion
from the matrix. An element stiffness deactivation method in conjunction with critical radial stress criterion is successfully
demonstrated using finite element method. The proposed methodology is shown to capture the experimentally observed debonding
process well.
相似文献
H. V. TippurEmail: |
950.