Hybrid experimental measurement of sectional stiffness properties of the MERIT rotor blade with digital image correlation

Abstract

A method to experimentally determine the sectional stiffness properties of modern fiber composite rotor blades is presented. This study hereby follows the novel approach introduced by Sinotte and Bauchau [1, 2]. The hybrid method relies on the measurement of the strain field and combines it with a numerically determined warping field. The strain field is measured using Digital Image Correlation (DIC)-a contact-free, optical 3D deformation measurement method in order to analyze and calculate deformations. The warping displacement field is recovered from a 2D cross-sectional structural analysis using the preprocessor SONATA and ANBA4. The design and manufacturing of the herein presented test article, the first rotor blade specifically developed for the Munich Experimental Rotor Investigation Testbed (MERIT) [3, 4], is described in detail and sectional stiffness properties are calculated based on the experimentally measured strains and loads.