PSI - Issue 81

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 81 (2026) 388–395

© 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of DMDP 2025 organizers Keywords: non-destructive testing; identification; elastic properties; composites; modal analysis; design of experiments method; global optimization. 1. Introduction Composite materials, and in particular carbon-fiber-reinforced polymers (CFRPs), are increasingly employed in aerospace, energy, and other high-performance engineering applications (Wollmann et al., 2016). Their highly tailorable anisotropy allows engineers to optimize stiffness and strength along preferred load paths, thereby achieving superior specific mechanical performance. However, this same directional dependence of material properties introduces significant challenges for the experimental Abstract This work presents a non-destructive approach for determining the effective elastic properties of carbon fiber reinforced polymer laminated composites. Two types of laminates were considered: unidirectional and twill-weave carbon-fiber composites. The purpose of the study is to estimate the quality of a numerical- experimental method for identifying the elastic moduli and Poisson’s ratios of orthotropic materials. The method combines vibration testing data with finite element modeling and global optimization. To validate the performance of the identification methodology, data from a virtual experiment on the numerical determination of the natural frequencies and vibration modes of a free rectangular plate were used. In the first stage of the identification procedure, a refined finite element model of the plate with initial guess values of the elastic constants was employed to determine the natural frequencies. The initial guess values of elastic constants were obtained using the design of experiments method. In the second stage, response surfaces were constructed to approximate the structural behavior of the composite plate. The elastic properties were analyzed to determine the influence of parameters that do not affect the natural frequencies. Finally, identification of material properties was performed by minimizing the error functional between the virtual experimental and numerical frequency values. The minimization was carried out using the differential evolution algorithm for global optimization. The results indicate that, although the methodology accurately identifies the dominant in-plane elastic constants of orthotropic composite laminates, it does not permit reliable estimation of out-of-plane properties due to their negligible influence on the measured natural frequencies. Consequently, the approach should be considered as a partial identification tool focused on the most dynamically influential parameters. VIII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2025) Non-destructive identification of effective elastic properties of carbon fiber reinforced polymer laminates using modal parameters Andrejs Kovalovs a , Oleh Derkach b* , Valerii Kobzar b a Riga Technical University, Kipsalas Street 6A, LV-1048 Riga, Latvia b G.S. Pisarenko Institute for Problems of Strength of the National Academy of Sciences of Ukraine, Sadovo-Botanichna 2, Kyiv 01014, Ukraine

* Corresponding author. Tel. +380-63-323-7231. E-mail address: derkach@ipp.kiev.ua

2452-3216 © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of DMDP 2025 organizers 10.1016/j.prostr.2026.03.067