三维数字相关应变测量技术研究及其应用于微观力学

Digital speckle correlation technique is one of important directions in experimentalmechanics. Except it has many advantages like non-contact, high accuracy, full-fieldmeasurements that own by optical interferometry, it has otheradvantages like simpleapparatus, wide measuring range, use white light source and in-situ measurements. Due toabove reasons, the wide applications of digital speckle correlation method are obvious and.it has occupied an important position in mechanical testing techniques..The research project has completed the basic research on correlation function,.correlation search, sub-pixel search, wavelet transform, de-noise etc. The project alsoimproves the measuring techniques on measuring speed, accuracy and range that make thistechnique more important in microphenomenon even nanophenomenon measurements. Onthe otherhand, in the practical displacement measurements, 3D displacement field exist,.the normal digital correlation strain measurements is 2D strain measurement. It isn’tsensitive to out of plane displacement, so it is important to develop 3D strain fieldtechnique for expanding digital correlation strain measuring technique. This projectcompleted the research and experiment in two aspects that are project speckle method forout of plane displacement measurements and 3D displacement measurements usingtwo-camera system. It resolves the 3D displacement measurements. Based on these basicresearches the project make more progress in application techniques that are applicationswhite light speckle correlation to mechanical behavior measurments of rock, rubble andcomposite. A new genetic algorithm is developed for the nanometer deformationmeasurement using electronic microscope, It creates a new direction for application digitalspeckle correlation method to micro-mechanics.

数字相关技术由于其众多优点已成为近代光测力学的一种重要手段，但在应变测量精度及灵敏度尚需进一步改进。本研究应用变换及位移补偿方法提高测量精度，将干涉计量与相关技术结合解决离面位移测量以满足三维应变测量。本研究还将应用高分辨图象技术提高应变测量灵敏度，并用于微区纳米级微变形测量，为应变梯度理论及尺寸效应提供实验依据。