Page 40 - FDMAsia Jul/Aug 2026

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

The Graphene Solution transfer through both contact pressure and friction.
Configuration 3P40 reached a maximum contact pressure
of 16.05 MPa and a maximum frictional stress of 4.11 MPa,
which were slightly lower than those obtained for 3P30.
The maximum sliding distance further decreased to 0.123
mm, indicating reduced relative movement between the

connector and the slot walls.
However, this lower sliding did not lead to a higher global
reaction force. The FEM reaction force for 3P40 was 73.70
N, compared with 80.03 N for 3P30.
This indicates that increasing the infill density from 30
a higher mechanical response, whereas increasing the perimeter percent to 40 percent improved positional stability, but did
count to 5P did not lead to a proportional improvement in not improve the overall load-transfer capacity of the joint.
material efficiency. The FEM model systematically underestimated the
Therefore, the 3P group was used as a representative experimental reaction force by 14.6–23.6 percent, with the

configuration for analysing the effect of infill density on the best agreement achieved for configuration 3P30.
contact behaviour. Although the model underestimated the absolute values
Contact behaviour was evaluated for the three 3P connector of the reaction force, it successfully captured the main
configurations at the loading state corresponding to 40 percent experimental trend.
of the maximum experimental load. Increasing the infill density from 20 percent to 30 percent
This pre-failure loading state was used to identify the main improved the joint response, whereas a further increase to
load-transfer mechanisms at the connector-wood interface 40 percent did not result in an additional improvement in the

before dominant damage occurred. global reaction force.
Three contact parameters were analysed at the connector- Configuration 3P30 provided the most balanced contact
wood interface: maximum contact pressure, maximum frictional response among the analysed 3P variants. It combined the
stress, and maximum sliding distance. highest contact pressure and frictional stress with relatively
For configuration 3P20, the maximum contact pressure low sliding and the highest FEM reaction force.
reached 12.58 MPa, the maximum frictional stress was 3.22 These findings are consistent with the experimental and
MPa, and the maximum sliding distance reached 0.162 mm. statistical results, which showed that increasing infill density
These values indicate relatively weak bearing of the beyond 30 percent did not provide a proportional improvement
connector against the slot walls and the highest relative in joint performance.

movement among the analysed 3P configurations. The observed failure modes depended on the perimeter
Increasing the infill density to 30 percent increased the configuration. For connectors with one perimeter (1P), complete
maximum contact pressure to 17.94 MPa and the maximum fracture of the connector shank was observed.
frictional stress to 4.74 MPa, while the maximum sliding Connectors with three perimeters (3P) exhibited visible
distance decreased to 0.138 mm. localised deformation of the connector shank, accompanied
This suggests that configuration 3P30 provided better seating in some specimens by partial splitting of the wood along
of the connector in the wooden slot and more effective load the grain.