## 5 Conclusions  
In general, it can be said that CAx systems are used in every part of the enterprise to cover the process of design, construction, simulation, analysis, and even maintenance and production [29; 30; 31]. The theoretical part of this article presents a description of the current state of solving the problem of using CAx systems. In particular, such includes current CAx systems used in the aviation industry, their development, and the selection of the aircraft design node, on which we pointed out the use of CAx systems for practice. The research activity thematically follows from the theoretical part of the article. Its goal is to design a suitable CAx system for the creation of visualization and simulation of the aircraft structural unit, to propose a method of modeling the selected aircraft structural unit, and then to implement the selected simulation using CAx systems for the selected element of the aircraft structural component. The summary of the main contributions of this article to the development of the theory and methodology of designing aircraft structural components can be summarized in the following points:  
1. Creation of 3D models (considering the actual shape and dimensions) of individual construction elements of the aircraft structural component. Utilization of 3D scanner and specialized software. 2. Application and development of selected graphic modeling methods and tools in the field of designing aircraft structural components utilizing CAx software. 3. Conduction of thermal stress testing on a real aircraft component, the small jet engine MPM-20. 4. Thermal stress testing of its digital twin. 5. Analysis of the obtained data. 6. Formulation of knowledge usable for modeling the design of other structural components of the aircraft. This study highlights the use of a 3D handheld scanner to create a visualization of 3D models for aircraft structural units. Implementation and experimental verification of the creation of visualization of 3D models of individual construction elements of the aircraft structural unit using a 3D handheld scanner, along with verification of data collection used for simulation using new technology, could be highlighted as practical benefits of this study. The implementation of the proposed benefits in the design of aircraft structural nodes brings numerous advantages [32]. These include reducing redundant design steps; increasing the efficiency of designing aircraft structural components; and accelerating the creation of 3D models of individual construction elements, as well as the complete assembly. The final assembled CAD model is shown in Appendix B, Figure 12.  
Data obtained by testing a real object, a small MPM-20 jet engine, and data obtained by simulating thermal entrainment on its digital twin and comparing them confirmed predictions of where thermal expansion and stress would be most noticeable. Drawing from this conclusion, it is reasonable to indicate, by observing the necessary methodology and using best practices, that testing the temperature load on the digital twin of the selected component yields identical results as testing the real object in laboratory conditions. When verifying the results, the places with the highest temperature load were identical. This testing method therefore also represents a contribution to the field of non-destructive testing (NDT) of structural components, where these results and findings can be applied to other industries outside of aviation, such as the automotive and engineering industries. The simulation was conducted to compare and validate results with temperature tests performed on a real object. The testing of the real object occurred under laboratory conditions at the laboratory of intelligent aircraft control systems, Faculty of Aeronautics TUKE. The potential for replacing real component testing with simulated testing of a component's digital twin exists, providing strict adherence to procedures for creating a digital twin to ensure the highest possible resemblance to its real-world counterpart.