用有限元分析的数值模拟方法(A N SY S)研究剪切散斑无损检测,已经受到了人们的极大关注。以剪切散斑无损检测为背景,以有无缺陷试件为模型,对模型进行有限元总体分析,运用计算机数值模拟出在载荷作用下含缺陷试件覆盖层的形变状态。结...用有限元分析的数值模拟方法(A N SY S)研究剪切散斑无损检测,已经受到了人们的极大关注。以剪切散斑无损检测为背景,以有无缺陷试件为模型,对模型进行有限元总体分析,运用计算机数值模拟出在载荷作用下含缺陷试件覆盖层的形变状态。结果表明,当缺陷变化时,对最大离面位移差均有不同程度的影响,未来可以将此方法应用于无损检测中,从而定量检测出缺陷的位置。展开更多
Digital speckle technique uses a laser, a CCD camera, and digital processing to generate interference fringes at the television framing rate. Its most obvious advantage is that neither darkroom facilities nor photogra...Digital speckle technique uses a laser, a CCD camera, and digital processing to generate interference fringes at the television framing rate. Its most obvious advantage is that neither darkroom facilities nor photographic wet chemical processing is required. In addition, it can be used in harsh engineering environments. This paper discusses the strengths and weaknesses of three digital speckle methodologies. (1) Digital speckle pattern interferometry (DSPI) uses an optical polarization phase shifter for visualization and measurement of the density field in a flow field. (2) Digital shearing speckle interferometry (DSSI) utilizes speckle\|shearing interferometry in addition to optical polarization phase shifting. (3) Digital speckle photography (DSP) with computer reconstruction. The discussion describes the concepts, the principles and the experimental arrangements with some experimental results. The investigation shows that these three digital speckle techniques provide an excellent method for visualizing flow fields and for measuring density distributions in fluid mechanics and thermal flows. 展开更多
文摘用有限元分析的数值模拟方法(A N SY S)研究剪切散斑无损检测,已经受到了人们的极大关注。以剪切散斑无损检测为背景,以有无缺陷试件为模型,对模型进行有限元总体分析,运用计算机数值模拟出在载荷作用下含缺陷试件覆盖层的形变状态。结果表明,当缺陷变化时,对最大离面位移差均有不同程度的影响,未来可以将此方法应用于无损检测中,从而定量检测出缺陷的位置。
文摘Digital speckle technique uses a laser, a CCD camera, and digital processing to generate interference fringes at the television framing rate. Its most obvious advantage is that neither darkroom facilities nor photographic wet chemical processing is required. In addition, it can be used in harsh engineering environments. This paper discusses the strengths and weaknesses of three digital speckle methodologies. (1) Digital speckle pattern interferometry (DSPI) uses an optical polarization phase shifter for visualization and measurement of the density field in a flow field. (2) Digital shearing speckle interferometry (DSSI) utilizes speckle\|shearing interferometry in addition to optical polarization phase shifting. (3) Digital speckle photography (DSP) with computer reconstruction. The discussion describes the concepts, the principles and the experimental arrangements with some experimental results. The investigation shows that these three digital speckle techniques provide an excellent method for visualizing flow fields and for measuring density distributions in fluid mechanics and thermal flows.
