Failure mode analysis and prediction model of additively manufactured continuous carbon fiber‐reinforced polylactic acid

Abstract

Carbon fiber‐reinforced composites are widely used in aerospace, rail transportation, and new energy vehicles due to their small specific gravity as well as good mechanical and chemical properties. Additive manufacturing of continuous carbon fiber‐reinforced polymer composites is an innovative composite manufacturing technique. In this paper, bending and shear specimens with different hatch spacing and layer thicknesses were prepared by fused filament fabrication (FFF) technique and subjected to three‐point bending experiments and interlayer shear experiments, respectively. The results showed that the maximum flexural strength and flexural modulus of the fabricated parts were 383.81 MPa and 41.23 GPa, respectively, and the maximum interlayer shear strength was 13.64 MPa. Finally, an optimized criterion for determining fiber kinking, fiber breakage, and matrix damage was proposed by considering in situ strength variations induced by process parameters. This new model was subsequently validated and could provide a method for fracture predicting of additive manufactured carbon fiber‐reinforced composites.Highlights CCFRC parts with different porosities were prepared by adjusting the layer thickness and hatch spacing. The bending and interlaminar shear damage mechanisms of CCFRC fabrications are revealed, and the effects of layer thickness and hatch spacing on their mechanical properties are investigated. Introduction of additive manufacturing factors to optimize failure models for CCFRC parts. Introduction of additive manufacturing coefficients to accurately predict the interlaminar shear strength of CCFRC parts by AM.