Reinforcement Elements Aligned with the Direction of Forces for Load Transfer Areas of Long-Fiber-Reinforced Thermoplastic Components

2015 ◽  
Vol 825-826 ◽  
pp. 779-786 ◽  
Author(s):  
Katharina Arnaut ◽  
Patrick Schiebel ◽  
Anna Lang ◽  
Axel S. Herrmann

Large-scale production of carbon fiber reinforced plastics often fails due to the increased material and manufacturing costs. Using the lightweight potential for competitive costs of materials, new construction methods are necessary, which enables an intelligent use of continuous fiber reinforcement, a largely automated production process as well as short cycle times. [1] The combination of continuous fiber reinforcement in the areas of maximum loads and cheaper materials such as long-fiber reinforced thermoplastic offers an efficient material application. Thereby, a required ratio of mechanical properties and attractive cost profile can be achieved.

2018 ◽  
Vol 2 (3) ◽  
pp. 56
Author(s):  
Andreas Gomer ◽  
Wei Zou ◽  
Niels Grigat ◽  
Johannes Sackmann ◽  
Werner Schomburg

Ultrasonic fabrication of fiber reinforced plastics made from thermoplastic polymer films and carbon or glass fibers enables cycle times of a few seconds and requires investment costs of only some 10,000 €. Besides this, the raw materials can be stored at room temperature. A fiber content of 33 vol % and a tensile strength of approximately 1.2 GPa have been achieved by ultrasonic welding of nine layers of foils from polyamide, each 100 µm in thickness, and eight layers of carbon fibers, each 100 µm in thickness, in between. Besides unidirectional carbon fiber reinforced polymer composite (CFRP) samples, multi-directional CFRP plates, 116 mm, 64 mm and 1.2 mm in length, width and thickness respectively, were fabricated by processing three layers of carbon fiber canvas, each 300 µm in thickness, and eight layers of polyamide foils, each 100 µm in thickness. Furthermore, both the discontinuous and the continuous ultrasonic fabrication processes are described and the results are presented in this paper. Large-scale production still needs to be demonstrated.


2016 ◽  
Vol 36 (6) ◽  
pp. 589-596 ◽  
Author(s):  
Christian Hopmann ◽  
Philipp N. Wagner ◽  
Robert Bastian ◽  
Kai Fischer ◽  
Arne Böttcher

Abstract In order to reduce cycle times, increase functional integration and automation further, the innovative gap impregnation process and mold technology was developed at the Institute of Plastics Processing at RWTH Aachen University (Germany) in collaboration with industry partners. The novel process enables an automated production of continuous fiber-reinforced sandwich composite structures in integral design with high surface quality in short cycle times, which is demonstrated by manufacturing a carbon fiber-reinforced plastic (CFRP) engine hood. For the first time, the gap impregnation and mold technology makes it possible to manufacture large-scale, three-dimensionally shaped sandwich components in one shot and in short cycle times at similar mechanical properties compared to the reference steel hood. Furthermore, a weight reduction of about 60% to only 5 kg was achieved for the CFRP engine hood. This paper focuses on the systems engineering of the RTM-related gap impregnation process. The focus is on the utilized mold concepts for the pressurized air-assisted ejector pins, vacuum-tight sealing, the motion concept of the mold halves, resin traps, sensors for process control and the specially treated mold surfaces for class A surface components. Additionally, the main procedures, capabilities and characteristics of this innovative process are discussed.


2021 ◽  
Author(s):  
Vicky Reichel ◽  
Jan Beuscher ◽  
André Hürkamp ◽  
Klaus Dröder

Hybrid structures made of fiber-reinforced plastics (FRP) and metals are currently in focus of research and industry to develop weight reduced and functional optimized components for lightweight solutions. Manufacturing processes were adapted and developed to produce components based on hybrid materials with high economic efficiency. The cutting process is used to pre-assemble the semi-finished products or to post-process the edges of consolidated parts. The mechanisms of damage edge behavior and possible cutting qualities on these parts are not investigated jet. To close this knowledge gap and to support the future application of hybrid FRP-Metal-Laminates different cutting procedures were studied. This paper shows the process related dependences on the failure behavior of two dimensional specimens. The failure modes are described via quality characteristics like surface roughness, trueness and precision of the cut as well as influences of aging processes. In the end optimized parameter for each process are shown and compared under technical and economic criteria for large scale production. In the scope of this work an experimental study of piercing of glass and carbon fiber reinforced thermoplastic with different steel and bonding agents at different cutting sequences were performed. It was shown that the cutting edge geometry significantly differs. Possible mechanical explanations of the dependencies were formulated. Also the accuracy of the cuts was evaluated which showed a higher accuracy for the steel component. The measurements on the surface roughness could not show any dependencies and relations.


Author(s):  
Aditya R. Thakur ◽  
Ming C. Leu ◽  
Xiangyang Dong

Abstract A new additive manufacturing (AM) approach to fabricate long fiber reinforced composites (LFRC) was proposed in this study. A high deposition rate was achieved by the implementation of a single-screw extruder, which directly used thermoplastic pellets and continuous fiber tows as feedstock materials. Thus, the proposed method was also used as a large-scale additive manufacturing (LSAM) method for printing large-volume components. Using polylactic acid (PLA) pellets and continuous carbon fiber tows, the feasibility of the proposed AM method was investigated through printing LFRC samples and further demonstrated by fabricating large-volume components with complex geometries. The printed LFRC samples were compared with pure thermoplastic and continuous fiber reinforced composite (CFRC) counterparts via mechanical tests and microstructural analyses. With comparable flexural modulus, the flexural strength of the LFRC samples was slightly lower than that of the CFRC samples. An average improvement of 28% in flexural strength and 50% in flexural modulus were achieved compared to those of pure PLA parts, respectively. Discontinuous long carbon fibers, with an average fiber length of 20.1 mm, were successfully incorporated into the printed LFRC samples. The carbon fiber orientation, distribution of carbon fiber length, and dispersion of carbon fiber as well as porosity were further studied. The carbon fibers were highly oriented along the printing direction with a relatively uniformly distributed fiber reinforcement across the LFRC cross section. With high deposition rate (up to 0.8 kg/hr) and low material costs (< $10/kg), this study demonstrated the potentials of the proposed printing method in LSAM of high strength polymer composites reinforced with long carbon fibers.


2006 ◽  
Vol 306-308 ◽  
pp. 851-856
Author(s):  
C.Y. Son ◽  
H.I. Byun ◽  
K.H. Kim ◽  
J.K. Choi ◽  
J.Y. Shin

In these days, large-scale wind turbines are being made of the Glass Fiber Reinforced Plastic (hereinafter F.R.P). Some reinforcement stiffeners such as carbon fiber and polyamide (Kevlar) are not economical for the wind turbine. In addition, the steel or aluminum alloy, featuring heavy weight and metallic fatigue load, is not suitable for global use, except very small-scale wind turbines. In this study, we manufactured a 10kW-grade small Rotor Blade with the F. R. P featuring high stiffness and good dynamic behavior characteristic, and carried out experiments for understanding the bending behavior characteristic of the fatigue load and bending load. And, we examined the experiment results through the Finite Element Method. We compared the experiment results and FEM analysis outputs using the commercial ANSYS FEM program.


2016 ◽  
Vol 47 (8) ◽  
pp. 2153-2183 ◽  
Author(s):  
Azam Ali ◽  
Khubab Shaker ◽  
Yasir Nawab ◽  
Madeha Jabbar ◽  
Tanveer Hussain ◽  
...  

There is a growing interest in the development of natural fiber-reinforced composites, most likely due to their wide availability, low cost, environment friendliness, and sustainability. The market size for natural fiber-reinforced composites is projected to reach $5.83 billion by 2019, with a compound annual growth rate of 12.3%. The composite materials reinforced with wood, cotton, jute, flax or other natural fibers fall under this category. Meanwhile, some major factors limiting the large scale production of natural fiber composites include the tendency of natural fiber to absorb water, degradation by microorganisms and sunlight and ultimately low strength and service life. This paper has focused to review the different natural fiber treatments used to reduce the moisture absorption and fiber degradation. The effect of these treatments on the mechanical properties of these composites has also been summarized.


2016 ◽  
Vol 9 (S3) ◽  
pp. 12-17
Author(s):  
Jens Lotte ◽  
Alexander Schiebahn ◽  
Uwe Reisgen

2016 ◽  
Vol 36 (6) ◽  
pp. 597-605 ◽  
Author(s):  
Ariane Jungmeier

Abstract Injection moulding is a widespread large-scale production technology for the manufacturing of thermoplastic parts, with small wall thicknesses limiting the feasible flow length. Introducing microthermoforming into the injection moulding process with dynamic mould temperature control enables the production of film-based, plane microstructured parts with further three-dimensional functional structures (e.g. for handling or for fitting in devices/assembly groups). Investigations show that considerable forming is possible with pressures up to 140 bar and forming temperatures far below the glass transition temperature of 50-μm-thick polycarbonate films in cycle times of <3 min. Generally speaking, the novel technology is expected to allow for multifunctional, thin-walled microstructured parts at large scales with short cycle times.


2020 ◽  
Vol 3 (1) ◽  
pp. 231-240
Author(s):  
Łukasz Bołoz ◽  
Antoni Kalukiewicz ◽  
Greg Galecki ◽  
Liubomyr Romanyshyn ◽  
Taras Romanyshyn ◽  
...  

AbstractOne of the basic methods of mechanical rock mining is cutting, which faces increasingly difficult working conditions. Despite the rapid development of machines used in underground and opencast mining as well as in tunnel building, construction industry and road engineering, the problem of insufficient durability of mining tools remains unsolved. In addition to drilling and, to a lesser extent, planing, cutting provides a huge market for tools. Currently, the process of cutting is mainly based on conical picks. The cutterheads of cutting machines are equipped with several dozen, and frequently – more than one hundred conical picks, which, due to their workability and abrasiveness, sometimes work only a few hours. There is a market demand for over two hundred models of conical picks. This is due to the huge variety of shapes and sizes of picks as well as the methods of their mounting in the holder. The article briefly presents various solutions of conical picks, their construction, methods of protection, dimensions and materials used. Next, based on materials produced by ZWM Carbonex, the classic method of their manufacture using the turning technology has been described. The authors have also presented briefly the use of die forging for the large-scale production of picks, applied by Górnicza Fabryka Narzędzi Sp. z o.o.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1082 ◽  
Author(s):  
Ruoxuan Huang ◽  
Siqi Ma ◽  
Meidi Zhang ◽  
Jie Yang ◽  
Dehong Wang ◽  
...  

The wear evolution of the glass fiber reinforced Polytetrafluoroethylene (PTFE) sliding against duplex steel at elevated temperature was investigated using the interrupted wear tests coupling with the worn surface observations. The morphological changes of the PTFE composite during the sliding were related to the variation of the tribological properties to analyze the underlying wear mechanisms. Results show that the coefficient of friction and wear rate change with the increase of temperature. During the sliding, three regions can be identified regardless of the temperature. The high temperature is beneficial to the formation of tribo-film. The sequence of wear evolution is PTFE removal, load transfer to glass fiber, and minor formation of tribo-film for the low temperature condition. For high temperatures, the wear behaviors are more complicated. The different phenomena include the third body abrasion, flake delamination of PTFE matrix, scratching and reformation of transfer film on the counterface, and the filling of the large scale PTFE groove. These behaviors may dominate the different stages in the stable region, but occur simultaneously and cause the dynamic steady wear. As a result, the wear rate at 200 °C is slightly fluctuant.


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