Systematic analysis of the mechanical anisotropy of fibre-reinforced polymer specimens produced by laser sintering

Khudiakova, A.; Berer, Michael; Niedermair, Siggy; Plank, Bernhard; Truszkiewicz, Eliza; Meier, G. H.; Stepanovsky, H.; Wolfahrt, Markus; Pinter, Gerald; Lackner, J.M.

doi:10.1016/j.addma.2020.101671

Cited by 16 publications

(11 citation statements)

References 28 publications

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“…Therefore, the “ISO-X” threshold procedure as reported in the previously published work (Senck et al , 2007; Plank et al , 2015) was used. The applicability of this grey value-based method to MEX specimens was demonstrated by researchers Khudiakova et al and Savandaiah et al (Khudiakova et al , 2020; Savandaiah et al , 2021a, 2021b). The high-resolution scan with a voxel edge length of 1 µm was performed on a cut out of the PC-L-PA6-±45° sample with a size of approximately 10 × 1.5 × 1.5 mm³ and was used to determine the appropriate ISO value for the void analysis of a scan with 7 µm voxel edge length.…”

Section: Methodsmentioning

confidence: 82%

Rapid consolidation of 3D printed composite parts using compression moulding for improved thermo mechanical properties

Savandaiah

Maurer

Plank

et al. 2022

RPJ

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Purpose 3D printing techniques such as material extrusion based additive manufacturing provide a promising and cost effective manufacturing technique. However, the main challenges in industrial applications remain with the quality assurance of mass produced parts. The purpose of this study is to investigate the effect of compression moulding as a rapid consolidation method for 3D printed composites, with an aim to reduce voids and defects and thus improving quality assurance of printed parts. Design/methodology/approach To develop an understanding of the inherent voids in 3D parts and the influence on mechanical properties, material extrusion additively manufactured (MEX) parts were post consolidated by using compression moulding at elevated temperature. Findings This study comparatively investigates the influence of carbon fibre length, undergoing process induced scission during filament extrusion and IM and its impact on void content and mechanical properties. It was found that the post consolidation significantly reduced the voids and the mechanical properties were significantly improved compared to the nonconsolidated material extrusion additively manufactured parts, reaching values similar to those of the IM parts. Practical implications Adaptation of extrusion-based additive manufacturing with hybridisation of reliable compression moulding technology transcends into series production of highly adaptive end user applications, such as drones, advanced sports prosthetics, competitive cycling and more. Originality/value This paper adds to the current understanding of 3D printing and provides a step towards quality assurance for mass production.

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Section: Methodsmentioning

confidence: 82%

Rapid consolidation of 3D printed composite parts using compression moulding for improved thermo mechanical properties

Savandaiah

Maurer

Plank

et al. 2022

RPJ

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“…provided a thorough evaluation of fiber orientation in 3D. [ 146 ] Other than calculating 2D optical images, this work used two software tools of iAnalyse and VG to analyze the micro‐CT results for the evaluation of fiber alignment. The findings showed that 50% to 60% of fiber orientation was along the roller spreading direction; 30% to 40% was perpendicular to it but also in‐plane; and only 5% to 15% was out‐of‐plane.…”

Section: Powder Bed Fusionmentioning

confidence: 99%

3D‐Printed Anisotropic Polymer Materials for Functional Applications

et al. 2021

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Anisotropy is the characteristic of a material to exhibit variations in its mechanical, electrical, thermal, optical properties, etc. along different directions. Anisotropic materials have attracted great research interest because of their wide applications in aerospace, sensing, soft robotics, and tissue engineering. 3D printing provides exceptional advantages in achieving controlled compositions and complex architecture, thereby enabling the manufacture of 3D objects with anisotropic functionalities. Here, a comprehensive review of the recent progress on 3D printing of anisotropic polymer materials based on different techniques including material extrusion, vat photopolymerization, powder bed fusion, and sheet lamination is presented. The state‐of‐the‐art strategies implemented in manipulating anisotropic structures are highlighted with the discussion of material categories, functionalities, and potential applications. This review is concluded with analyzing the current challenges and providing perspectives for further development in this field.

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“…This software package includes a porosity/inclusion analysis tool, as well as tools to determine mean gray values of certain defined regions of interest. Segmentation and three-dimensional visualization of the defect structures were done by applying a simple threshold method often used for porosity [36,37] or matrix evaluations [38] in composites. To determine a proper threshold value, a multiscale approach as shown in the study by Kastner et al [37] is usually used.…”

Section: A13 | Determination Of Modulus In Cyclic Testsmentioning

confidence: 99%

Characterization methods for strain‐induced damage in polypropylene

Wiener

Preissegger

Plank

et al. 2022

Polymer Engineering & Sci

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Various methods are used to characterize the deterioration of mechanical properties in polymers. The focus is set on distinguishing between time‐dependent and irreversible damage in two different grades of polypropylene. First, digital image correlation is utilized to capture the stress–strain behavior during monotonic tensile tests. Changes in specimen volume are recorded throughout the experiment and serve as an indicator for crazes and voids. However, the elastic modulus, E, cannot be monitored throughout the entire experiment. Further analysis is performed in the form of cyclic load–unload tests. E and the residual strain, εres, as a function of the applied strain, εappl, are obtained for each cycle. Results show that E primarily suffers from the time‐dependent behavior of the tested polymers in this case. Subsequently, an alternative technique is applied, where specimens are prestrained and then allowed to relax. In the following dynamic mechanical analysis, viscoelastic effects can be avoided. Considerations on the onset and evolution of damage are made. Ultimately, these results are confirmed through microcomputed tomography, where the shapes and densities of defects are captured in high resolution.

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Systematic analysis of the mechanical anisotropy of fibre-reinforced polymer specimens produced by laser sintering

Cited by 16 publications

References 28 publications

Rapid consolidation of 3D printed composite parts using compression moulding for improved thermo mechanical properties

Rapid consolidation of 3D printed composite parts using compression moulding for improved thermo mechanical properties

3D‐Printed Anisotropic Polymer Materials for Functional Applications

Characterization methods for strain‐induced damage in polypropylene

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