Showing papers by "K. Ramesh published in 2005"
TL;DR: In this article, the multi-parameter stress field equations of Deng are simplified for use by experimentalists to evaluate the stress field parameters by digital photoelasticity using an overdeterministic least-squares technique.
Abstract: Photoelastic evaluation of the stress intensity factor (SIF) for a crack in a bimaterial tangential to the interface is hitherto confined to the use of only a singular stress field equation. In this paper, the multi-parameter stress field equations of Deng are simplified for use by experimentalists to evaluate the stress field parameters by digital photoelasticity using an overdeterministic least-squares technique. A bimaterial Brazillian disc with a central interface crack is selected as the model for study as different mode mixities could be easily simulated by changing the crack orientation angle. The use of SIF evaluation based on a singular stress field equation is found to be inadequate for the problems considered. On the other hand, the use of a multi-parameter stress field equation is quite successful in evaluating the stress field for various mode mixities and for two values of bimaterial constant. It is shown that the new procedure allows data collection from a larger zone, which helps to simpli...
26 citations
TL;DR: A comprehensive ambiguity removal methodology is demonstrated in this paper and has also been proposed to remove the lines and marks from the phase-shifted images.
Abstract: Phasemaps obtained by phase-shifting techniques contain ambiguous zones. To obtain total fringe order by phase unwrapping, the phasemap should be corrected for ambiguity. Each available ambiguity removal method can resolve ambiguity for only a class of problems. Appropriate selection of these algorithms and their combination for a specific case can give a better result. A comprehensive ambiguity removal methodology is demonstrated in this paper. Disturbance in the intensity pattern of the phase shifted images due to lines and marks on the models lead to noise in phasemaps. This in turn affects the ambiguity removal and unwrapping procedures. A methodology has also been proposed to remove the lines and marks from the phase-shifted images.
7 citations