## 5 Conclusions  
The developed method aims at the automated identification of the orthotropic engineering constants of composite materials as a function of temperature. Relatively large thin plate and beam samples are suitable for the analysis of composite materials. Only minimal preparation of the test sample was required (cutting beams and adjusting the sizes of the Poisson plate). The results were averaged over the area of the test samples. The simple yet accurate impulse excitation technique (IET) was chosen for measuring resonance frequencies and damping ratios. IET is a non-destructive technique, allowing measurements at different temperature steps. The developed pendulum mechanism is easily implemented in existing climate chambers. Pendulum excitation avoids multiple hits, and the position and quality of the impact can be adjusted according to sample requirements. The Resonal-yyer procedure is a mixed numerical-experimental method that requires only resonance frequencies and damping ratios. No modal shape values are required; thus, full operational modal analysis or experimental modal analysis is unnecessary. Identification of the complex engineering constants with the Resonalyser procedure takes less than a second and can be executed in real time after each completed measurement step. However, measurement of the damping ratios exhibits considerable noise, so identification should preferably be carried out as postprocessing after smoothing with spline polynomials. The test performed on a bidirectionally glass-reinforced composite material with a thermoplastic matrix PA6 revealed significant variation of all engineering constants within the tested temperature range of \(-20\)\({}^{\circ}\)C to \(60\)\({}^{\circ}\)C. Given the novelty of the method, numerous issues require more detailed investigation across various materials in future research.  
Conceptualization, H.S. and J.G.; methodology, H.S.; software, H.S.; validation, J.G., G.N. and G.M.H.; formal analysis, H.R. and G.M.H.; investigation, J.G., G.M.H. and G.N.; resources, J.G. and G.N.; data curation, G.N.; writing--original draft preparation, H.S.; writing--review and editing, H.S.; visualization, J.G.; supervision, H.R.; project administration, H.R.; funding acquisition, H.S. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Flemish government institute VLAIO with grant number HBC 2019.0120 (2020-2024). Data Availability Statement: Data is contained within the article.  
The authors thank the Flemish government institute VLAIO for their financial support in the ICON research project HBC 2019.0120 (2020-2024), in which a functional prototype instrument was developed. VLAIO will also support the authors in finding industrial partnerships for further development of the prototype.  
Co-author [PERSON] was employed by BYTEC BV., the remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} IET & Impulse excitation technique \\ IRF & Impulse response function \\ DMA & Dynamic mechanical analysis \\ EMA & Experimental modal analysis \\ OMA & Operational modal analysis \\ FE & Finite element \\ ASTM & American Standard Testing Materials \\ \end{tabular}