TWI Industrial Member Report Summary 985/2011
By Jianxin Gao
Optical techniques in experimental mechanics have the advantages of whole-field, non-contact or remote measurement of surface displacement and/or deformation (eg bending, elongation, twisting etc) of a structural component such as a test specimen or equipment under load. By capturing a series of images of a specimen during its dynamic deformation, quantitative information about its mechanical behaviour can be obtained. This information can be valuable in the evaluation of materials and components. With the rapid advancements in opto-electronics and computer hardware, the resolution and capability of digital image techniques have been significantly improved. For example, image resolution of 4,000 to 10,000 pixels on each dimension is available in a moderately-priced commercial CCD camera. This leads to a displacement sensitivity of up to one 100,000th of the dimension of the field of view (FOV) of the object under investigation, or 10µm for a 1m FOV. Therefore, optical and digital image techniques show promise for quantitative measurement of dynamic deformation processes for material characterisation and structural evaluation.
- Develop an image processing software package for displacement and deformation measurement.
- Carry out case studies to verify the capabilities of the technique in displacement and deformation measurement of structural components.