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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4. Results With respect to the clearly defined objective of the presented parametric study, it was necessary to determine the differences in performance distribution between the parts of the coupling to provide information on which geometry could be the best for manufacturing and subsequent experimental testing. Figure 4 shows the results of the critical target that is referenced for the limit points of each material.

3D print

Steel

Wood

0 1 2 3 4

Force [kN]

V01

V02

V03

V04

V05

Fig. 4. Graphical expression of the limiting forces for the analysed geometries relative to each of the materials used.

The highest force (2.93 kN) for the 3D printed element was obtained for sample V02. A similar value (2.88 kN) was achieved for sample V03. In contrast, the lowest force was achieved by specimen V04 (1.99 kN), where we can see that the load transfer was provided by the wooden prism. Very interesting are the different values of the force at which the steel pins plasticize. It can be assumed that at that moment the pins bend and the internal force transfer is distributed to the wooden element. Thus, the graphs show that the higher achieved force in the wood is paired with the low achieved force in the 3D element. To better understand the differences between the geometries, the percentage flattening in Figure 5 can be used. If you take the first geometry variant as a reference, we can determine the relative improvement or deterioration of the other 4 variants. From these data we can see that the biggest difference in the internal force distribution is in the V04 variants, where the steel pins plasticize with a significant advance at 43 % less force. Similarly, the 3D printed joint in the V04 variants ceases to perform its function at 22 % less force. Comparing the results, V01 is the most suitable variant for the boundary conditions and loading method specified here. Different results could be achieved if the orientation of the load test is changed, or the loading scheme or span is changed. The anisotropic properties of the wood or the layering of the 3D printed elements and the quality of the fasteners produced are the main factors affecting the results. Steel pins are one of the most stable elements in the joint, retaining their properties under load and thus not significantly affecting the results compared to the behaviour and properties of wood and 3D printed materials.

edge for plastic strain (3D print)

edge for yield stress (steel)

edge of shear stress (wood)

5%

V02/V01

-13%

-7%

4%

V03/V01

-22%

-3%

-28%

V04/V01

-43%

29%

-8%

V05/V01

-30%

20%

Fig. 5. Percentage difference between the first geometry limit force values and other variations for each material in the models.