Investigation on mechanical characteristics of modified TPMS primitive PLA-CF mechanical metamaterials.

Mechanical metamaterials are novel engineering materials which helped industries like aerospace to lighten their structure while maintaining the strength in an acceptable range. This study focused on the effect of strut diameter on specific characterization of these novel mechanical metamaterials including mechanical and energetic characteristics through experimental and Finite element method investigations. A Modified Primitive TPMS lattice structure with eliminated curves at nodal points has produced with five different strut diameter, 1.5, 2.0, 2.5, 3.0, and 3.5 mm through FDM additive manufacturing of carbon fiber filaments and taken to examination under the uniaxial compression test. The yield point was enhanced by increasing the strut diameter from 6.49 to 16.77 MPa. Moreover, the strength-to-weight ratio of the structures remain constant due to high stress toleration of heavier lattice structure, it means the high numbers of tolerated stress has unaffected the effect of increased weight for these lattice structures. Energetic properties, the structures shown high rates of energy absorption efficiency (90%) while showing great energy absorptions which is the effect of optimization of the unit-cell. In the end, maintaining the same specific characteristic while mechanical attributes are increased is an achievement and could be very beneficial in industries which aimed to increase the mechanical properties while seeking an specific weight range.