Tribology and Materials | Volume 2 | Issue 2 | 2023 | 62-67

Modal analysis of composite plates: Digital image correlation method application

Marija Baltić1, Miloš Vorkapić2, Milica Ivanović1, Dragoljub Tanović1, Ivana Mladenović2

1 University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia
2 University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia


Abstract: Composite materials and structures are widely used and applied in many industries owing to their advantages, such as satisfactory stiffness-to-mass ratio and corrosion resistance. However, during their operating life, responsible parts subject to complex loads may change and their properties might deteriorate. To ensure structural integrity it is necessary to monitor and regularly check the performance of composite structures. This paper investigates the change of frequency characteristics of two rectangular composite (carbon-epoxy) plates after inflicting structural damage. Following the necessary preparation of the structure's upper surfaces by white-and-black stochastic pattern, the responses (free vibratory movement) of structures to momentary excitation were recorded by an optical, contactless 3D digital image correlation (DIC) system that contains a set of ultrafast cameras. In order to determine the natural frequencies of the plates, the recorded time-domain responses were post-processed, i.e. converted to the frequency domain by fast Fourier transform (FFT). The reduction in values of natural frequencies is observed on the damaged structures. The performed experiments demonstrate the applicability of the DIC method in the structural health monitoring of composite parts.

Keywords: composite structures, laminates, DIC system, modal analysis, natural frequency.

Received: 14-03-2023, Revised: 19-06-2023, Accepted: 21-06-2023

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license, which allows users to distribute, remix, adapt, and build upon the material in any medium or format for non-commercial purposes only, and only so long as attribution is given to the creator.