PSI - Issue 73

Dominik Gřešica et al. / Procedia Structural Integrity 73 (2025) 27 – 32 Dominik Gřešica, Petr Lehner, David Juračka / Structural Integrity Procedia 00 (2025) 000 – 000

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screws, dowels or tenon joints have their limits, especially in terms of design flexibility, manufacturing complexity and potential weakening of the wood (Ernur et al., 2022). In recent years, there has therefore been a growing interest in new technologies that would allow overcoming these obstacles and optimizing the joining process (Lehner et al., 2024; Nicolau et al., 2022). This work focuses on the research and development of 3D printed plastic joints for joining timber-timber structures. 3D printing offers a unique opportunity to create complex geometries with high precision and design flexibility, allowing joints to be optimized for specific loads and aesthetic requirements (Hu, 2021; Su and Al’Aref, 2018) . A key part of the research is numerical modelling using the finite element method (FEM) (Bathe, 2008). FEM allows us to simulate the behaviour of joints under different loads, optimize their design and predict their mechanical properties. The beginnings of the research program were presented, for example, in earlier articles (Dedek et al., 2024; Juracka et al., 2022). This parametric study is an integral part of an extensive research program that includes a comprehensive design, sophisticated numerical modelling and thorough validation with experimental data. This research programme focuses on innovative design solutions in the field of hybrid building elements, combining the advantages of traditional materials such as wood with progressive technologies such as 3D printing, allowing the creation of complex geometries and optimised structures. The results of an early geometric variant, shown in Figure 1, have already been published in an earlier publication (Lehner et al., 2024), providing a solid foundation for further development and analysis. The main goal of this research is to develop sustainable and efficient architecture that maximizes resource utilization and minimizes environmental impact.

Fig. 1. Visualization of the early variant of a 3D printed joint with connected wooden element. Reprinted from Lehner et al., 2024.

Furthermore, as part of this study, two geometric variations were investigated in detail, differing in the way the 3D printed element and the wooden element were combined. This approach allows for flexibility in design and optimization of the properties of the hybrid components, taking into account specific loading and performance requirements. The objective of this particular parametric study was to establish a suitable and systematic procedure for finding the ideal geometry of the test specimens that would optimally combine the properties of both materials. 2. Parametric study of geometry variants The numerical modelling process in Ansys software (ANSYS, 2020), which included the definition of boundary conditions, material settings and the establishment of evaluation criteria, was carefully applied to the new geometry. This complex process was crucial to ensure the accuracy and reliability of the simulation results. By ensuring fixed parameters for all simulations, it was possible to fairly compare the different geometries. This consistency was key to ensuring comparability of results. Once all parameters were set, it was possible to proceed with the simulation. By using identical parameters for all simulations, it was possible to perform a comparative analysis of five different