Quantitative strength analysis for 3D-printed specimens in a Tri-Hexagon pattern

Abstract

ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic acid) are the most commonly used thermoplastic materials in the AM (Additive Manufacturing) to build objects adding layer by layer. Addition of reinforcement such as carbon fibres to these materials is common to enhance strength properties. This work aims the fabrication of ABS, PLA, and PLA+CF specimens using the FDM (Fused Deposition Modeling). Subsequently, the tensile strength of printed specimens at Tri-Hexagon pattern for various % infills with different orientations is investigated. For a desired strength, the analysis facilitates the designer to choose suitable combination of specimen orientation at a specific infill and pattern. PLA+CF and ABS specimens with Tri-hexagon pattern at 0° orientation retain considerable strength when infill % gets lowered, whereas, virgin PLA observes higher strength stability at 90° orientation. The magnitudes of Ultimate tensile strength increased with infill %. The peak strength for PLA+CF specimen (with 100% infill without any pattern) at 0° and 90° orientation was 22% and 5% more, respectively, compared to 45° orientation. SEM images reveal a decrease in strength with ABS and PLA specimens due to the presence of voids between the layers, whereas showed strong bonding between CF and PLA matrix. Tri-Hexagon pattern showed better strength than the honeycomb, line, and rectilinear, especially at lower infills. Specimens both with and without Tri-hexagonal pattern observed superior ductile characteristics at 0° and 90° orientation, whereas most inferior at 45°.