Stress-adapted fiber orientation along the principal stress directions for continuous fiber-reinforced material extrusion
- A proven method to enhance the mechanical properties of additively manufactured plastic parts is the embedding of continuous fibers. Due to its great flexibility, continuous fiber-reinforced material extrusion allows fiber strands to be deposited along optimized paths. Nevertheless, the fibers have so far been embedded in the parts contour-based or on the basis of regular patterns. The outstanding strength and stiffness properties of the fibers in the longitudinal direction cannot be optimally utilized. Therefore, a method is proposed which allows to embed fibers along the principal stresses into the parts in a load-oriented manner. A G-code is generated from the calculated principal stress trajectories and the part geometry, which also takes into account the specific restrictions of the manufacturing technology used. A distinction is made between fiber paths and the matrix so that the average fiber volume content can be set in a defined way. To determine the mechanical properties, tensile and flexural tests are carried out on specimens consisting of carbon fiber-reinforced polyamide. In order to increase the influence of the principal stress-based fiber orientation, open-hole plates are used for the tensile tests, as this leads to variable stresses across the cross section. In addition, a digital image correlation system is used to determine the deformations during the mechanical tests. It was found that the peak load of the optimized open-hole plates was greater by a factor of 3 and the optimized flexural specimens by a factor of 1.9 than the comparison specimens with unidirectional fiber alignment.
Author: | Tim HeitkampORCiD, Sebastian KuschmitzORCiDGND, Simon GirnthORCiD, Justin-Dean MarxORCiD, Günter Klawitter, Nils Waldt, Thomas VietorORCiDGND |
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URN: | urn:nbn:de:bsz:960-opus4-24064 |
DOI: | https://doi.org/10.25968/opus-2406 |
DOI original: | https://doi.org/10.1007/s40964-022-00347-x |
ISSN: | 2363-9512 |
Parent Title (English): | Progress in Additive Manufacturing |
Document Type: | Article |
Language: | English |
Year of Completion: | 2022 |
Publishing Institution: | Hochschule Hannover |
Release Date: | 2022/12/15 |
Tag: | Curvilinear fiber; Design for additive manufacturing; Fiber reinforced additive manufacturing; Material extrusion; Principal stress Continuous fiber |
GND Keyword: | Extrudieren |
Page Number: | 19 |
Institutes: | Fakultät II - Maschinenbau und Bioverfahrenstechnik |
DDC classes: | 670 Industrielle und handwerkliche Fertigung |
Licence (German): | ![]() |