Page 27 - IJB-9-4

International Journal of Bioprinting Lattice-Solid hybrid 3D printing for artificial implant

Table 1. FEA results for maximum von Mises stress under Table 2. FEA results for displacements under various loading
various loading conditions conditions
Specimens Maximum von Mises stress (MPa) Specimens Displacements (μm)
400 N 500 N 600 N 400 N 500 N 600 N
P-type 20% 37.0 46.2 55.5 P-type 20% 4.5 6.2 7.5
P-type 40% 79.6 99.5 119.4 P-type 40% 22.8 28.5 34.3
P-type 60% 273.9 342.3 410.8 P-type 60% 85.3 106.6 127.9
P-type 80% 769.3 961.6 1154.0 P-type 80% 205.3 256.6 308.0
P-type 100% 1495.9 1525.3 1563.8 P-type 100% 770.3 1044.2 1610.1
S-type 10% 30.3 37.9 45.5 S-type 10% 2.8 3.5 4.2
S-type 20% 36.9 46.2 55.4 S-type 20% 5.1 6.4 7.7
S-type 30% 48.2 60.5 72.3 S-type 30% 5.9 7.4 8.9
S-type 40% 44.7 55.9 67.0 S-type 40% 5.0 6.3 7.6
S-type 50% 46.0 57.5 69.0 S-type 50% 2.4 3.0 3.6

Figure 4. FEA results for the lattice structure with different sizes and unit cell rotation. (a) 2 mm with 0° (1525 MPa); (b) 3 mm with 0° (1611 MPa);
(c) 2 mm with 45° (1456 MPa).

The cross-section illustration of P- and S-type hybrid 50%, respectively. In the case of S-type, since 50% of
structures for the volume fraction of the lattice structure solid beam exists inside, the volume fraction of the lattice
is shown in Figure 5. P- and S-type specimens analyzed structure was set to 10%–50%. When the volume fraction
under a load of 500 N, which was determined considering is 20%, the maximum von Mises stress is 46.2 MPa, which
the weight of an average human. The P-type hybrid is similar to the results for the P-type. However, when the
structure was simulated with various volume fractions of volume fraction is 40%, the maximum von Mises stress
20%–100%, respectively (Figure 6). The maximum von is 55.9 MPa, which is much lower than the result of the
Mises stress increased as the volume fraction of the lattice P-type with 99.5 MPa. In addition, in the case of the S-type,
structure increased. When the volume fraction is 20%, the the maximum von Mises stress did not increase rapidly
maximum von Mises stress is 46.2 MPa. Up to 40% of the even when the volume fraction was increased to 50%,
volume fraction, the maximum von Mises stress shows a whereas in the case of the P-type, it increased rapidly when
small increase of less than 100 MPa. However, from 60% the volume fraction was increased to 60% (Figure 8). In
of the volume fraction, the maximum von Mises stress particular, the maximum von Mises stress at 50% volume
increased significantly. When the volume fraction is 60%, fraction for the S-type was 57 MPa, while it exceeded 300
it is 342.3 MPa, and when the volume fraction is 100%, it is MPa for the P-type at a volume fraction of 60%. As a result
961.6 MPa, which increases more than two times compared of FEA simulations, the maximum von Mises stress was
to the previous case. similar when the volume fraction of lattice structure was
Figure 7 shows the simulation results for the S-type low in both P- and S-type, but in the case of P-type, it
hybrid structure with various volume fractions of 10%– increased rapidly as the volume fraction increased.

Volume 9 Issue 4 (2023) 19 https://doi.org/10.18063/ijb.716