Optical measurement of an impact reaction in a modeled wing

Abstract

In this research, an impact reaction which was provoked far from its origins was studied. A metal box filled with sand was used to emulate a rigid body in which a steel bar was embedded; these conditions simulated the fuselage and wing, respectively, and the impact was applied to the rigid body and the measurement to the bar. For this, an optical technique was used to measure the relative displacement of the steel bar, and the measurements are obtained by applying digital image correlation; 2D images were obtained from the speckles generated as a reflection of the beam on the material. The results were studied through the modified Gauss–Newton analytical approach obtaining a maximum standard error deviation of 0.144 from the experimental results.

Optical Analysis of the Impact Transmission in Steel Sheet Arrays with Bolted-Type Joints

“…Finally, the authors reported another solution for a damped oscillator, in which they showed a combination of harmonic and linear functions [9]. In comparison with these studies, the present article demonstrates that the analytical results reproduced the experimental motion in every array.…”

“…According to the analytical solutions shown in [7][8][9], first, the authors declared a sum of two waves as the first analytical approximation to the motion recorded experimentally. This solution gave them an accuracy of 92%.…”

“…where C c is the mathematical correlation. Normalization is performed, stating M as the image size and s 1 and s 2 as the standard deviation of the images corresponding to [8,9]. Equation ( 2) gives a matrix-type result; thus, the maximum amplitude point was logically defined.…”

“…It is part of the intensity field I in (1), and it is related to the real and imaginary part of the complex amplitude of each speckle [32]. As this is an iterative process, from the second to the n image, those peak amplitudes are plotted as scalar values measured in millimeters according to [8,9].…”

“…Finally, an approximation to a modeled wing was handled, in which impacts were subjected to a rigid body, but reactions were measured in an embedded bar. Results were modeled with a damped oscillator with linear and harmonic excitation [9].…”