Scanning laser vibrometer for non-contact three-dimensional displacement and strain measurements

Abstract

The recent advent of three-dimensional scanning laser vibrometers has enabled extremely accurate non-contact measurement of the three-dimensional displacements of structures. This paper looks at the feasibility of using a scanning laser vibrometer for the non-contact measurement of dynamic strain fields across the surface of a planar structure. Is-sues such as laser head alignment and choice of finite-difference scheme are discussed. Finally, experimental results of a test specimen are presented which clearly demonstrate the significant potential of this new experimental technique.