动态白光散斑法的灵敏度及其提高

本文用非相干成象系统频谱分析的概念,分析了动态白光散斑法的灵敏度问题。提出了提高灵敏度的方法,使之不仅能测量大的动态变形,而且也能测量小的动态变形,如果用光弹性材料作试件,能同时得到动态等差线,进行主应力分离。

The Sensititvity of The Dynamic white Light Speckle Method and Its Improvement

The dynamic deformation of structures can be measured by white light speckle method. Using rhc WZDD-1 model dynamic photoelastic instrument as the high speed photographic system, the tesolution, of rhc instrument is So low and the reduction of the significant cut-off frequency produced by defocusoing is so large that the sensitivity of the dynamic white light speckle is low and its use-is limited The sensitivity of the dynamic white light speckle method is analysed with the concept of the frequency spectrum analysis of the incoherent imaging system and the method of raising the sensitivity is presented in this paper. The sandwich and mismatch speckle method and the direct re-cording method without the lens (subjective speckle) are used and the sensitivity of the dynamic whitelight speckle method is improved. A small dynamic deformation at .1 highly elastic modulus ma-tetial is measured, when the resolution of rhc lens is low, and experimental results are obtained. If the photoelastic material is raken as rhe specimen, the dvnamic isoromate patterns are obtained at the same time under the same load. Thus, the principal stress is separated or the stress is acquired directlyfrom the strain. Therefore the stress and strain of rhe structure are solved. (Chen pingping and Li Gongyu participated in this test)