Tensile properties of 3D-printed PLA prismatic cellular structures: an experimental investigation

Advancements in additive manufacturing have significantly increased the use of cellular structures in product development, especially in the automotive, aerospace, and biomedical industries, due to their enhanced strength-to-weight ratio and energy-absorbing capabilities. This study investigates the tensile properties of 3D-printed PLA prismatic cellular structures, focusing on the effects of fillet radius, wall thickness, and cell size on tensile strength, Young's modulus, and strength-to-weight ratio. Using a full factorial design and ANOVA, we examined the impact and interaction of each geometrical parameter. Our findings show that triangular cellular structures exhibit a higher stiffness of 1.36 GPa and tensile strength of 24.28 MPa, resulting in a notable 5.78 MPa/gram strength-to-weight ratio. Increasing cell count and wall thickness enhances both tensile strength and Young's modulus, whereas adding fillet radii at corners reduces these properties. Fracture behaviors are influenced by geometrical design: shorter, thicker walls lead to progressive crack propagation, while longer, thinner walls tend to fail catastrophically. Fillet radius introduction shifts the fracture initiation point from the nodes. ANOVA results indicate that wall thickness and cell size significantly affect tensile strength and Young's modulus, contributing 36.53% and 53.54%, respectively.