title: Multipoint diffraction strain sensor with variable sensitivity.
abstract: In our earlier work, a multipoint diffraction strain sensor using a microlens array was developed for measurement of whole-field strains. The method is extended to a system with variable sensitivity and measurement range. In the present system, two collimated laser beams, 3 mm in diameter, symmetrically strike the grating attached to the specimen surface at prescribed angles. The diffracted wavefronts, magnified by a microscope objective, are sampled by a lenslet array with each microlens acting as an individual strain sensor. In-plane strain components over the full field can be measured by what is to our knowledge a new sensor with variable sensitivity by changing the distance from the microscope objective to the microlens array. Both a theoretical explanation and experimental verification are provided.
authors: School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
authors: Jun
authors: J
authors: Wang
authors: Anand K
authors: AK
authors: Asundi
authors: Wei
authors: W
authors: Zhou
authors: Lennie E N
authors: LE
authors: Lim