Article
Construction & Building Technology
Daniel Friedrich
Summary: This study investigated the impact of temperature, heating time, bending radius, and fiber content on the mechanical properties and memory behavior of extruded wood-plastic composite (WPC) cladding after thermoforming. The results showed that higher temperatures facilitated forming with smaller radii but significantly decreased strength. Fiber content had a comprehensive influence on the material behavior. For industrial implementation, rupture modulus and retention force should be used for development and process control, while research should focus on compound optimization.
AUTOMATION IN CONSTRUCTION
(2022)
Review
Engineering, Industrial
Samantha Webster, Hui Lin, Fred M. Carter, Kornel Ehmann, Jian Cao
Summary: The study defines hybrid additive manufacturing as a combination of additive manufacturing process and secondary energy sources, altering physical mechanisms to influence material properties. Through a systematic approach, the study identified five physical mechanisms and analyzed over 100 papers to show the effects of mechanisms on material properties. Future research directions include improving energy source variety, material diversity, process chain integration, and developing promising hybrid additive manufacturing processes.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Engineering, Manufacturing
Lu Lu, Shangqin Yuan, Xiling Yao, Yamin Li, Jihong Zhu, Weihong Zhang
Summary: Multi-sensing and correlation analyses are essential for online process evaluation and optimization in order to improve the quality of as-fabricated components. In this study, a framework of multi-sensor fusion for CFRP additive manufacturing is proposed, integrating different sensors to obtain online datasets and establishing correlations between process parameters/pattern features and defects/surface quality. The use of multi-sensor fusion enables effective online monitoring and process evaluation.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Composites
Robert Setter, Florentin Riedel, Wolfgang Peukert, Jochen Schmidt, Katrin Wudy
Summary: The study investigates a novel multi-material additive manufacturing technology that enables the infiltration of reactive liquids in a thermoplastic powder bed, and experimental and mathematical approaches were utilized to describe and predict the infiltration behavior. The mathematical model proved to accurately describe the infiltration process, showing the independence of the form factor from different powder parameters. Through SEM images, a theory was presented linking the form factor to the microstructural shape and surface condition of the particles.
POLYMER COMPOSITES
(2021)
Article
Chemistry, Physical
Anamaria Feier, Ioan Buta, Cosmina Florica, Lucian Blaga
Summary: The paper discusses the CNC component manufacturing process using the WAAM process. It describes all the execution steps from CAD drawing to examination and economic calculation. The WAAM process proves to be more advantageous, especially when a single piece is needed and expensive titanium alloys are used. The cost of obtaining a component using the WAAM process is significantly lower compared to using another manufacturing process, as shown in this paper. In conclusion, additive manufacturing can be a feasible solution for industrial applications when replacing a classic manufacturing process.
Review
Engineering, Manufacturing
Jennifer Bracken Brennan, Timothy W. Simpson, Christopher McComb, Kathryn W. Jablokow, Joseph Hamann
Summary: As additive manufacturing (AM) becomes more popular, companies are seeking to identify parts that can be produced using AM. This paper reviews and compares 13 published part filtering methods, categorizing and sorting them while examining them through the lens of process specificity. A new part filtering method is proposed and tested, showing improvements in engineers' ability to identify suitable parts for AM.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Manufacturing
Hui Chen, Tan Cheng, Qingsong Wei, Wentao Yan
Summary: The dynamic behaviors of short fiber/polymer composite powders in powder paving process of additive manufacturing were investigated through discrete element method simulations.
It was found that the compaction of the mixed powders in the counter-rolling form powder paving is stronger, resulting in a denser powder layer compared to the scraping form.
Furthermore, the powder layer density decreases with an increase in paving speed, and an increase in fiber length will reduce the spreadability of the mixed powders and hence decrease the packing density of the powder layer.
ADDITIVE MANUFACTURING
(2021)
Article
Automation & Control Systems
Austen Thien, Christopher Saldana, Thomas Kurfess
Summary: This study investigates the impact of varying dwell time and input deposition power on wire arc additive manufacturing, concluding that lower input power and dwell time can significantly reduce production time.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Materials Science, Ceramics
Meysam Mohammadi Zerankeshi, Sayed Shahab Sayedain, Mobina Tavangarifard, Reza Alizadeh
Summary: Developing a uniform polymer-based composite filament is crucial for successful 3D printing. This study proposes a novel method for fabricating PLA-graphite filament and compares it with the solvent casting method. The modified mixing technique enhances the adhesion of reinforcement powders by dissolving the surface of PLA pellets, resulting in excellent structural features and mechanical properties of the manufactured composite filament.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Muammel M. Hanon, Arsany Ghaly, Laszlo Zsidai, Szilvia Klebert
Summary: The manufacturing process has been greatly influenced by the introduction of 3D printing and graphene. This study explores the tribological behavior of 3D printed graphene/resin composite and finds that graphene significantly reduces the friction coefficient and affects the surface roughness, microstructure, wear, and hardness characteristics of the material.
MATERIALS & DESIGN
(2022)
Article
Engineering, Manufacturing
Shenli Pei, Kaifeng Wang, Cheng-Bang Chen, Jingjing Li, Yang Li, Danielle Zeng, Xuming Su, Hui Yang
Summary: This study investigated the inherent variabilities in the fused filament fabrication of short carbon-fiber-reinforced Nylon-6 composites under different process conditions, quantifying the sources of uncertainty and their effects on microstructures and Young's modulus. Microstructural characteristics were extracted and uncertainties quantified via image-based data analytics and analysis of variance. A modified Halpin-Tsai model with consideration of fiber and void distributions was developed to quantify uncertainties on Young's modulus and validated through tensile tests.
JOURNAL OF MANUFACTURING PROCESSES
(2021)
Article
Polymer Science
Fabian Ferrano, Tizian Wachter, Miranda Fateri, Michael Schmiedt
Summary: The influence of extrusion infill angles on the mechanical properties of 3D printed test specimens were investigated in this study. Different polylactide (PLA) specimens with varying infill angles were manufactured and tested using Computed Tomography (CT) scanning and optical measuring system. The results showed significant deviation between the real geometry behavior and the model. Finite Element Method (FEM) simulations were also conducted, which predicted an increase in stiffness, ultimate tensile strength, and strain at failure due to geometric deviation. The goal of this work is to evaluate the stiffness and strength of FFF-printed components using FEM with a justifiable testing effort, considering the directional dependence and suitable strength criterion.
Article
Materials Science, Composites
Yong Du, Jiageng Chen, Jie Qin, Qiufeng Meng, Shirley Z. Shen
Summary: The PVA/PEDOT:PSS composite films prepared via solution 3D printing technology exhibit significantly improved electrical conductivity and power factor, with the conductivity increasing to 1085 S/cm and power factor increasing to 45 μWm(-1)K(-2). Additionally, the composite films show excellent flexibility and resistance change rate after bending for 300 times.
COMPOSITES COMMUNICATIONS
(2022)
Article
Materials Science, Ceramics
Megane Bernard, Vincent Pateloup, Damien Passerieux, Dominique Cros, Valerie Madrangeas, Thierry Chartier
Summary: Additive manufacturing technology enables the production of complex 3D parts. A hybrid additive machine has been developed to manufacture ceramic/metal parts, and the co-debinding and co-sintering cycles have been optimized for quality assurance. However, the lack of dimensional accuracy in the metallic network leads to deviations in frequency responses compared to simulations.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Manufacturing
Jinxing Sun, Shixiang Yu, Wade-Zhu James, Yue Wang, Hongqiao Qu, Shuai Zhao, Rui Zhang, Jinglei Yang, Jon Binner, Jiaming Bai
Summary: Geometrically complex ceramic composite components with exceptional damage tolerance can be fabricated using additive manufacturing and novel biomimetic toughening design.
ADDITIVE MANUFACTURING
(2022)
Article
Chemistry, Physical
Julia Hofele, Guido Link, John Jelonnek
Summary: Microwave-based dielectric heating is an energy- and time-efficient method that should be considered during the production of carbon fibers. However, there is limited data on the dielectric properties of the processed material. This study presents in-situ measurements of dielectric properties during the stabilization stage of PAN fiber and establishes reaction kinetics and heat transfer models for monitoring and controlling the fiber temperature online.
Article
Thermodynamics
Yi Zhang, Sergey Soldatov, Ioannis Papachristou, Natalja Nazarova, Guido Link, Wolfgang Frey, Aude Silve
Summary: This study evaluated the efficiency of pulsed microwave (PMW) treatment on fresh Auxenochlorella protothecoides suspension and found that pulse properties had little effect on efficiency and lipid extraction performance. Lipid yield was positively correlated with energy input and influenced by algal concentration and suspension flow rate.
Article
Engineering, Electrical & Electronic
T. Rzesnicki, Z. C. Ioannidis, K. A. Avramidis, I. Chelis, G. Gantenbein, J. -P. Hogge, S. Illy, J. Jelonnek, J. Jin, A. Leggieri, F. Legrand, I. Gr. Pagonakis, F. Sanchez, M. Thumm
Summary: This article reports on the major achievements of the upgraded gyrotron during experimental campaigns at KIT. The upgraded gyrotron surpassed the performance of the previous version and delivered higher power output.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Vitalii Shcherbinin, Konstantinos A. Avramidis, Manfred Thumm, John Jelonnek
Summary: This article focuses on the theoretical aspects of mode selection and design for a gyrotron cavity loaded with a coaxial rod made of chemical vapor deposition (CVD) diamond. It presents the design of a high-Q diamond-loaded cavity for a third-harmonic 658-GHz gyrotron driven by a low-power electron beam. The results show that the designed cavity enables the gyrotron to produce high-power output in a single oscillating mode.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Physical
Jesus Nain Camacho Hernandez, Guido Link, Markus Schubert, Uwe Hampel
Summary: This paper proposes a new approach to estimate the thermal conductivity of open-cell solid foams based on their porosity, and it is validated by comparing with experimental and numerical data.
Article
Chemistry, Physical
Jesus Nain Camacho Hernandez, Guido Link, Markus Schubert, Uwe Hampel
Summary: In energy and process engineering systems, the removal of droplet-laden gas flows is challenging. This study presents a compact technology based on microwave heating that effectively captures and evaporates droplets, preventing system congestion and flooding.
Article
Engineering, Electrical & Electronic
Benjamin Ell, Chuanren Wu, Gerd Gantenbein, Stefan Illy, Moritz Misko, Ioannis Gr. Pagonakis, Manfred Thumm, John Jelonnek
Summary: Future fusion power plants will require high-power gyrotrons to generate microwave power for plasma heating and noninductive current drive. Increasing the sweeping frequency can reduce material fatigue and extend the device lifetime, but a higher frequency magnetic field is not efficient due to eddy currents. Instead, sweeping with electric fields is proposed for the first time to achieve a higher sweeping frequency.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Benjamin Ell, Chuanren Wu, Gerd Gantenbein, Stefan Illy, Moritz Misko, Ioannis Gr. Pagonakis, Joerg Weggen, Manfred Thumm, John Jelonnek
Summary: The multistage depressed collector (MDC) is crucial for increasing the overall efficiency of the gyrotron. A short pulse (SP) MDC prototype system has been manufactured and is being tested, while the long-term goal is to use MDCs on 2-MW fusion gyrotrons in continuous wave (CW) operation. A CW MDC system based on the same physical principle as the SP system has been designed and analyzed for the first time, with sweeping systems to control thermal loading in CW operation.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Konstantinos A. Avramidis, Alexander Marek, Ioannis Chelis, Zisis C. Ioannidis, Lukas Feuerstein, John Jelonnek, Manfred Thumm, Ioannis Tigelis
Summary: The possibility of parasitic excitation of backward waves directly in the gyrotron cavity is demonstrated, by simulation, for two existing high-power gyrotrons. The excited parasitic backward waves at high frequencies can lead to significant performance degradation. This finding provides an additional possibility for the origin of experimentally observed RF parasitic oscillations in high-power, high-frequency gyrotrons.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
Moritz Engler, Guido Link, John Jelonnek
Summary: This study presents a measurement system using a wall perturbation approach with a coaxial cavity to determine the effective conductivity of carbon-fiber-reinforced plastics (CFRPs) along the fiber direction.
Article
Engineering, Electrical & Electronic
Vitalii I. Shcherbinin, Manfred Thumm, John Jelonnek
Summary: This article introduces a new high-$Q$ dielectric-loaded cavity as an alternative to conventional cavity for terahertz gyrotrons. The cavity consists of a two-layered distributed Bragg reflector (DBR) resonator jointed to standard input and output cavity sections. It is shown that the selected operating mode can be efficiently excited by the same electron beam in both the conventional uniform resonator and the DBR resonator. The mode conversion at the junctions between DBR resonator and standard cavity sections is low, resulting in more than 99% output purity of the operating mode. It is established that the operating mode in the dielectric-loaded cavity benefits from exceptionally low ohmic losses, which improves mode selection. The use of sapphire DBR in an existing second-harmonic 0.5-THz gyrotron increases the ohmic quality factor of the operating mode and gyrotron efficiency by a factor of 8 and 6, respectively.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Adel Omrani, Rahul Yadav, Guido Link, John Jelonnek
Summary: In this article, a novel control method called microwave tomography-based control is proposed for industrial heating systems. It requires fast data acquisition and real-time imaging algorithms. The technique utilizes a multistatic uniform diffraction tomography imaging algorithm to estimate moisture distribution and retrieve electrical properties of targets in a fixed array MWT system.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Adel Omrani, Rahul Yadav, Guido Link, Timo Lahivaara, Marko Vauhkonen, John Jelonnek
Summary: In this study, a Bayesian inversion framework and a multi-static uniform diffraction tomography method are combined to improve the quality of microwave tomography imaging. The proposed approach significantly improves the reconstruction accuracy of moisture distribution in a polymer foam.
IEEE TRANSACTIONS ON COMPUTATIONAL IMAGING
(2022)
