Year: 2012
Type: conference-paper
Abstract: Strains experimentally measured with strain gauges can differ from those evaluated using the Finite Element (FE) method. This difference is due mainly to the assumptions and uncertainties inherent to each method. To circumvent this difficulty, we developed a numerical method based on Monte Carlo simulations to evaluate measurement uncertainties produced by the behaviour of a unidirectional welded gauge, its position uncertainty and its integration effect. This numerical method uses the displacement fields of the studied part evaluated by an FE analysis. The paper presents a study case using in situ data measured on a hydraulic turbine runner. The FE analysis of the turbine runner blade was computed, and our numerical method used to evaluate uncertainties on strains measured at five locations with welded strain gauges. Then, measured strains and their uncertainty ranges are compared to the estimated strains. The uncertainty ranges obtained extended from 74 μ to 165 μ . Furthermore, the biases observed between the median of the uncertainty ranges and the FE strains varied from −36 to 36 μ . Note that strain gauge measurement uncertainties depend mainly on displacement fields and gauge geometry.
Authors: J Arpin-Pont, M Gagnon, S A Tahan, A Coutu, D Thibault
Institutions: École de Technologie Supérieure, Hydro-Québec
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funder: Mitacs
OpenAlex ID: W1975210688