Page 38 - FDMAsia Jul/Aug 2026

36 TECHNOLOGY JUL/AUG 2026 FDM ASIA | www.fdmasia.com

Nodin Cutfeet prescribed displacement in the direction of loading. The FEM
model was evaluated under two loading conditions.
In the first loading condition, the model was loaded by
the experimentally determined displacement corresponding to
40 percent of the maximum experimental load.
This displacement-controlled state was used to evaluate

the pre-failure contact response of the joint and to identify
the load-transfer mechanism at the connector-wood interface
before dominant damage occurred.
Three contact parameters were evaluated: contact pressure,
frictional stress, and sliding distance. In the second loading
condition, the model was loaded by the mean maximum
separation, or local infill damage. experimental force of the corresponding connector configuration.
The contact between the FDM-printed connector and the This loading state was used to evaluate stress fields and
walls of the wooden slot was defined as frictional contact compare them with the experimentally observed damage.

with a coefficient of friction of 0.6. In the FDM-printed connector, equivalent von Mises stress
The selected value is comparable in magnitude to the was evaluated. In the wooden members, normal and shear
experimentally determined coefficient reported in the literature stresses were evaluated in the local material coordinate system
for frictional contact in beech mortise-and-tenon joints. because of the orthotropic nature of beech wood.
The contact pairs were solved using the Augmented
Lagrange formulation. To eliminate small numerical gaps Mechanical Performance and Material Efficiency
between the connector and the slot, the Adjust to Touch The mass of the printed connectors ranged from 2.57 g

option was applied, and the pinball radius was set to 0.5 mm. (1P20) to 5.09 g (5P40), with increasing perimeter count
This contact definition allowed load transfer through contact and infill density resulting in a gradual increase in material
pressure and friction while permitting local sliding between consumption. The maximum bending moment of the joints
the connector and the wood. ranged from 9,109 N·mm to 14,998 N·mm.
The finite element mesh was generated in ANSYS Mechanical. The highest mean rotational stiffness was recorded for
A global element size of 2 mm was applied, and adaptive configuration 3P30 (6,172 N·mm/deg), whereas the lowest
mesh refinement was used in regions of curvature and contact. value was observed for configuration 5P40 (4,476 N·mm/deg).
Mesh convergence was assessed for the representative The specific bending moment ranged from 2,608 N·mm/g
3P30 configuration, and the 2 mm mesh was retained as to 3,903 N·mm/g, with the highest mean value achieved by

sufficiently converged. configuration 3P20.
The boundary conditions were defined according to the The two-way ANOVA revealed statistically significant effects
experimental test configuration. The supported arm was of both perimeter count and infill density on the specific
represented by a Remote Displacement boundary condition, bending moment (p < 0.001 for both factors).
with translations constrained and rotation about the vertical The results indicate that, among the tested configurations,
axis left free. specific combinations of perimeter count and infill density
The load was applied at the end of the second arm as a provided a more favourable balance between mechanical