On the fatigue behavior of additive manufactured lattice structures

A numerical framework to predict the fatigue life of lattice structures built by additive manufacturing

“…has reached its fatigue life for a given maximum stress. The developed algorithm relies on the same idea proposed by Demiray et al and Zargarian et al in [24,26,27], whereas…”

“…Taking into account this damage accumulation is challenging. A few authors have attempted to do so (see e.g., [24,25,26,27]). They relied on a damage accumulation law based on the Miner's rule [28], consisting in adding up the damage of struts at the different stress levels they were submitted to.…”

Damage Tolerance Evaluation of E-PBF-Manufactured Inconel 718 Strut Geometries by Advanced Characterization Techniques

“…In regard to the cyclic material behavior of L-PBF-manufactured lattice structures, it has been stated that these properties are mainly affected by the type, size, and relative density of the cell, as well as the mechanical properties of the corresponding bulk material [16,21]. Furthermore, numerical simulations of additively manufactured lattice structures have already been carried out, e.g., by Zargarian et al [22]. In the aforementioned study the authors concluded that the relationship between cycles to failure and fatigue strength follows a power law; in particular, the influence of specific aspects like relative density and cell topology were highlighted.…”

Additive manufacturing and mechanical properties of titanium lattices for biomedical applications

“…The upper bound for biomedical materials is usually set to 10 5 or 10 6 cycles [135,138,139], as this corresponds to the repetitive cycles that occur in the implant applications [12]. Like tensile and compressive behaviour, the fatigue life of lattices is known to be affected by the bulk material, the unit-cell geometry and the relative density of the structure [140]. Yavari et al [138] reported that with similar relative densities, different unit-cells had significant variations in their fatigue life, which highlighted the role of the topology in the fatigue behaviour.…”

“…This statement is clearly supported by the S-N curves from Figure 2-19 that show variations in fatigue life for identical levels of porosity and different unit-cells. Additionally, the fatigue life has been found to always decrease with increase in level of porosity of the structure [140]. This is usually attributed to the additional sensitivity to manufacturing defects inherent to lattices [141].…”