大位移电子散斑干涉法

针对电子散斑干涉（ESPI）法处理大位移时的困难，提出了一种改进的ESPI法。将数字散斑相关法（DSCM）引入ESPI中，由DSCM计算引起散斑去相关的面内位移，将所得二维面内位移对失配散斑场进行校准，恢复干涉条纹。用对离面位移敏感的ESPI光路，结合相移方法求得对应离面位移的相位数据，和二维面内位移一起，构成物体三维位移。对周边同定、中心加载的有机玻璃试件进行了测量，结果表明能产生质量干涉条纹，证明该方法是合理、可行的。

Large Displacement Measurement Using ESPI

An improved electronic speckle pattern interferometry(ESPI) is presented to overcome the difficulty of ESPI in large displacement measurements.The large displacement of tested object causes the decorrelation of speckle pattern before and after loading and the deterioration of the fringe visibility.Therefore,no phase information corresponding to the deformation can be obtained.Digital speckle correlation method(DSCM) is incorporated into ESPI.DSCM is used to determine two-dimensional in-plane displacement,which is applied to rearrange the recorded speckles before and after deformation to retrieve the interference fringes.ESPI optical setup,which is sensitive to out-of-plane displacement,is adopted,so the phase map including out-of-plane displacement can be obtained with phase-shifting techniques.Therefore three-dimensional displacement can be obtained by integrating out-of-plane and in-plane displacements.To validate the new method,the experiment is provided.The tested object is an organic glass plate clamped around and forced in center.The results show that good quality fringes can be restored successfully.It proves that the method is feasible.