An approach to analyse errors introduced in the random grid strain measurement method

Iliopoulos, AP; Andrianopoulos, NP

dc.contributor.author	Iliopoulos, AP	en
dc.contributor.author	Andrianopoulos, NP	en
dc.date.accessioned	2014-03-01T01:32:41Z
dc.date.available	2014-03-01T01:32:41Z
dc.date.issued	2010	en
dc.identifier.issn	0039-2103	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/20203
dc.subject	Digital imaging	en
dc.subject	Mesh-free methods	en
dc.subject	Moving least squares	en
dc.subject	Random grid	en
dc.subject.classification	Materials Science, Characterization & Testing	en
dc.subject.other	Digital imaging	en
dc.subject.other	Exact solution	en
dc.subject.other	Field function	en
dc.subject.other	Full-field strain measurement	en
dc.subject.other	Mesh-free method	en
dc.subject.other	Meshfree	en
dc.subject.other	Moving least squares	en
dc.subject.other	Numerical derivation	en
dc.subject.other	Random grids	en
dc.subject.other	Sub pixels	en
dc.subject.other	Upper limits	en
dc.subject.other	Bubbles (in fluids)	en
dc.subject.other	Cameras	en
dc.subject.other	Computational mechanics	en
dc.subject.other	Crack initiation	en
dc.subject.other	Strain gages	en
dc.subject.other	Strain measurement	en
dc.subject.other	Systematic errors	en
dc.subject.other	Random errors	en
dc.title	An approach to analyse errors introduced in the random grid strain measurement method	en
heal.type	journalArticle	en
heal.identifier.primary	10.1111/j.1475-1305.2008.00444.x	en
heal.identifier.secondary	http://dx.doi.org/10.1111/j.1475-1305.2008.00444.x	en
heal.language	English	en
heal.publicationDate	2010	en
heal.abstract	The present work refers to the errors imposed by the recently introduced random-grid mesh-free full field strain measurement method. Excluding systematic errors of the digital camera, the method itself is not an error-free procedure. A possible cause of errors could be the misplacement of the spot-centre (centroid) with regard of the spot boundaries. Another cause of errors is the limited order of approximation in the field function. A third one, emerges from the so-called 'sub-pixel effect'. This kind of error is difficult to trace, so direct comparison between the results of the method and exact solutions is required. In the present work, proper analytical or numerical derivations of those errors are presented and reasonable upper limits are estimated. Finally, numerical and experimental examples are presented to demonstrate the accuracy of the method. © 2008 Blackwell Publishing Ltd.	en
heal.publisher	WILEY-BLACKWELL PUBLISHING, INC	en
heal.journalName	Strain	en
dc.identifier.doi	10.1111/j.1475-1305.2008.00444.x	en
dc.identifier.isi	ISI:000277714900007	en
dc.identifier.volume	46	en
dc.identifier.issue	3	en
dc.identifier.spage	258	en
dc.identifier.epage	266	en