Influence of in-plane displacement and strain components on curvature and twist fringe formation in simultaneous measurement of pure curvature and twist fringe distributions

摘要

The influence of in-plane displacement and strain components on curvature and twist fringe formation in five-aperture shearing and two-Fourier filtering speckle interferometry used for the simultaneous measurement of pure curvature and twist fringes is discussed. The results show that in-plane strain component ε_(ξ)(=partial derivd_(ξ)(ξ,η)/partial derivξ) has an influence on curvature partial deriv~(2)w(ξ,η)/partial derivξ~(2) fringe formation and that in-plane strain component γ_(xy)(=partial derivd_(x)(x,y)/partial derivy+partial derivd_(y)(x,y)/partial derivx) has an influence on twist partial deriv~(2)w(x,y)/partial derivxpartial derivy fringe formation. It can also be seen from the results that in-plane displacement components have no direct influence on curvature and twist fringe formation.