Title: MODELING OF MICROSTRUCTURAL IRREGULARITIES IN ADDITIVELY MANUFACTURED CONTINUOUS FIBER-REINFORCED POLYMERS

Authors: Yuri Nikishkov, Guillaume Seon, Brian Shonkwiler, Andrew Makeev

DOI: 10.33599/nasampe/s.23.0217

Abstract: The additive manufacturing (AM) process often produces parts with AM-specific microstructural irregularities. Example defects include voids, geometric errors, pathing errors, and variability of individual layers. Inherent susceptibility to these defects contributes to higher variability of part quality than found in parts manufactured using a traditional manufacturing process. The presence of microstructural defects at critical locations may significantly reduce strength and useful life of additively manufactured structures. Using continuous carbon fiber reinforced thermoplastics (CFRTPs) for primary structures is the newest and rapidly growing area in AM with adequate fiber volumes (50-60%) recently achieved. The manufacturing process deposits filaments that consist of continuous standard aerospace grade carbon fibers. Far more significant complexity of material microstructure including inherent discontinuities and defects have been observed in AM composite parts compared to metal structures. In this work, we present a Finite Element Modeling (FEM) framework that captures filament-level defects in as-manufactured CFRTP laminates. High-fidelity FE models are automatically generated from X-ray CT scans of CFRTP specimens and used for building complete filament-level models or representative volume element analysis. Novel ply segmentation method based on autocorrelation of fiber patterns efficiently detects filament waviness. FEM results are compared with experiments for box-beam test specimens.

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Conference: SAMPE 2023

Publication Date: 2023/04/17

SKU: TP23-0000000217

Pages: 16

Price: $32.00