Measurement of Beam Sectional Stiffness Properties

Abstract

Among all strain measurement techniques, digital image correlation is preferred over others because of its versatility, high accuracy and ability to produce full-field strain maps. The sectional stiffness properties of beams with simple configuration and made of homogeneous materials can be evaluated easily based on simple formulas. For aerospace applications, beams such as helicopter rotor blades present complex geometries and are made of heterogeneous, anisotropic composite materials. Evaluation of the sectional stiffness properties is an arduous task that requires a finite element based analysis of the cross-section. This thesis presents an approach that combines experimental measurements based on digital image correlation with a finite element model of the beam's cross-section to measure its sectional stiffness properties. The proposed approach is able to deal with rotor blades presenting arbitrary cross-sectional configuration made of anisotropic composite materials.