440 research outputs found
FDM Additive Manufacturing Fundamentals Orientation
No full textThis instructor resource from Portland Community College provides information on designing a course on fused deposition modeling (FDM) additive manufacturing. At the end of the course, students will be able to identify projects that are compatible for production on FDM machines, operate an FDM machine, and understand basic finishing techniques. This 1.5 credit course is designed for technical college classrooms. This packet includes a course outline, syllabus, sample course proposal form, a sample STL file, and the Rapid Prototyping Instructor’s Resource Manual.Below is a list of the files contained within the ZIP attachment. The size of each file is included in parenthesis. FDM Additive Manufacturing Fundamentals Orientation - 1.5 credit - (6 files, 310 KB)Contact information for the author - FDM Additive Manufactur (Contact information for the author - FDM Additive Manufactur.doc 25 KB)FDM Additive Manufacturing Fundamentals Orientation Course O (FDM Additive Manufacturing Fundamentals Orientation Course O.doc 68 KB)FDM Additive Manufacturing Fundamentals Orientation Syllabus (FDM Additive Manufacturing Fundamentals Orientation Syllabus.doc 36 KB)MCH 292 FDM Additive Manufacturing Orientation - New Course (MCH 292 FDM Additive Manufacturing Orientation - New Course.docx 25 KB)PDF 3 - RP Resource Manual - Finishing (PDF 3 - RP Resource Manual - Finishing.pdf 207 KB)TEST TWIST (TEST TWIST.STL 326 KB
Micromechanical Models for FDM 3D-Printed Polymers: A Review
No full textDue to its large number of advantages compared to traditional subtractive manufacturing techniques, additive manufacturing (AM) has gained increasing attention and popularity. Among the most common AM techniques is fused filament fabrication (FFF), usually referred to by its trademarked name: fused deposition modeling (FDM). This is the most efficient technique for manufacturing physical three-dimensional thermoplastics, such that FDM machines are nowadays the most common. Regardless of the 3D-printing methodology, AM techniques involve layer-by-layer deposition. Generally, this layer-wise process introduces anisotropy into the produced parts. The manufacturing procedure creates parts possessing heterogeneities at the micro (usually up to 1 mm) and meso (mm to cm) length scales, such as voids and pores, whose size, shape, and spatial distribution are mainly influenced by the so-called printing process parameters. Therefore, it is crucial to investigate their influence on the mechanical properties of FDM 3D-printed parts. This review starts with the identification of the printing process parameters that are considered to affect the micromechanical composition of FDM 3D-printed polymers. In what follows, their (negative) influence is attributed to characteristic mechanical properties. The remainder of this work reviews the state of the art in geometrical, numerical, and experimental analyses of FDM-printed parts. Finally, conclusions are drawn for each of the aforementioned analyses in view of microstructural modeling.Materials and Environmen
Susceptibility Study of TES Micro‑calorimeters for X‑ray Spectroscopy Under FDM Readout
No full textWe present a characterization of the sensitivity of TES X-ray micro-calorimeters to environmental conditions under frequency-domain multiplexing (FDM) readout. In the FDM scheme, each TES in a readout chain is in series with a LC band-pass filter and AC biased with an independent carrier at MHz range. Using TES arrays, cold readout circuitry and warm electronics fabricated at SRON and SQUIDs produced at VTT Finland, we characterize the sensitivity of the detectors to bias voltage, bath temperature and magnetic field. We compare our results with the requirements for the Athena X-IFU instrument, showing the compliance of the measured sensitivities. We find in particular that FDM is intrinsically insensitive to the magnetic fieldbecause of TES design and AC readout.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ImPhys/Optic
FDM Additive Manufacturing Fundamentals Orientation
No full textThese zipped documents from MatEd provide information on designing a course titled FDM Additive Manufacturing Fundamentals Orientation. At the end of the course, students will be able to identify manufactured projects or products that are compatible for production on FDM Machines, operate a Dimensions FDM machine, have proposed a project to reinforce these concepts, and understand basic finishing techniques to be applied to the parts. The documents include a draft syllabus, contact information for the author of the course, a sample new course proposal form, a course outline, and instructor's resource manual
Macro-meso dynamic analysis of railway transition zone: Hybrid DEM/FDM simulation and experimental validation
No full textTo probe into the mechanical behaviour of railway transition zone from the macro-meso aspects, a numerical model of transition zone is built that hybrids the Discrete Element Method (DEM) and Finite Difference Method (FDM). The DEM is utilised to simulate the ballast bed and sleeper, because it can consider the realistic ballast shapes and complex contacts between them. The FDM based on the continuum theory is utilised to simulate the track substructure according to a real structural form. Afterwards, the coupling algorithm is used to achieve the hybrid DEM-FDM simulation. The engineering practicality of this model is validated using the dynamic responses of the transition zone from a field measurement, and the macro-meso mechanical behaviour of the transition zone is analysed with or without the wedge-shape backfill. The numerical results indicate that applying the wedge-shape backfill can considerably reduce the sudden changes of track vibration and substructure surface stresses at the vicinity of the connection between the structure and embankment. Moreover, the mesoscopic results show that the acceleration vector of the soil near the rigid structure fluctuates towards the embankment and the velocity responses of track components and substructure increase gradually when the train travels from the rigid structure to the soft embankment.Accepted Author ManuscriptRailway Engineerin
Monitoring an air core by means of electrical resistance tomography
No full textWord processed copy.
Includes bibliographical references (leaves 129-133)
Reconstruction and Development of a 3D Printer Using FDM Technology
No full textAbstractThis study, we detail the constructional selection of a machine, which operates with FDM technology. We outline the milestones of the reconstruction of the printer, the restoration of the technical documentations (Reverse Engineering), and then the calibrations and the measurement results. Based on what we have learned from the construction, we started to design our own FDM printer, which is a compact, user demand-driven device
Noise Measurements of a Low-Noise Amplifier in the FDM Readout System for SAFARI
No full textThe SPICA-SAFARI instrument requires extremely sensitive transition edge sensor (TES) arrays with a noise equivalent power of 2×10-19W/Hz and a readout system with an output noise that is dominated by the detector noise. It is essential to ensure the frequency domain multiplexing (FDM) readout system in SAFARI meets the noise requirement. The FDM system in SAFARI consists essentially of LC filters, a superconducting quantum interference device, a room-temperature low-noise amplifier (LNA), and a demultiplexer. Here we present a noise study of the LNA from a laboratory amplifier chain. We found the equivalent current and voltage noise of the LNA to be 5.4pA/Hz and 315pV/Hz, respectively, which are low enough to read out SAFARI’s TES arrays.QN/Gao La
Fatigue behaviour of FDM-3D printed polymers, polymeric composites and architected cellular materials
No full textPolymer-based materials are increasingly produced through fused deposition modelling (FDM) – an additive manufacturing process, due to its intrinsic advantages in manufacturing complex shapes and structures at low overhead costs. The versatility of this technology has attracted several industries to print complex geometrical structures. This underlines the importance of studying the mechanical strength of FDM printed polymeric materials, especially their fatigue behaviour in cyclic loading conditions. Conventionally manufactured polymeric materials (e.g. injection moulding) have superior fatigue performance than FDM printed materials. Unlike conventionally manufactured polymers, FDM-made polymers have layer by layer adhesion and the influence of printing parameters make fatigue analysis complex and critical. The influences of printing parameters and printing material characteristics have a significant impact on the fatigue behaviour of these materials. The underlying mechanism behind the fatigue of FDM printed polymers is crucial for the assessment of these materials in structural applications. However, the fatigue behaviour of FDM printed polymeric materials has not been reviewed in detail. Therefore, this article aims to evaluate 3D printed polymeric materials’ fatigue properties. The importance of fatigue in the FDM printed biomedical materials is also reviewed, and more importantly, the novel FDM printed architected cellular material fatigue properties are also introduced. © 2020 The Author(s
Economic evaluation of FDM 3D printing technology in elektrotechnical industry
No full textTato bakalářská práce se zabývá 3D tiskem FDM metodou, porovnáním vlastností jednotlivých materiálů a komplexním ekonomickým zhodnocením provozu 3D tiskárny. Nejprve jsou probrány principy FDM metody, spolu s rešerší její historie. Dále se práce zaměřuje na porovnání důležitých vlastností vybraných materiálů používaných pro 3D tisk. Autor provedl měření a vyhodnocení důležitých fyzikálních vlastností vybraných materiálů s příměsí mědi. Jedná se konkrétně o tepelné, elektrické a mechanické vlastnosti. Práce popisuje způsob a metody použité při měření a výpočtu těchto veličin s pomocí podpůrných programů měřicích zařízení. V posledních kapitolách autor analyzuje výdaje spojené s investičními a provozními náklady 3D tiskárny Prusa i3 MK3S a provádí kalkulaci nákladů pro tisk konkrétního výrobku používaného v elektronice. Výsledky kalkulace jsou porovnány s tradiční výrobou vstřikolisovou metodou.This bachelor thesis deals with 3D printing by FDM method, properties comparison of individual materials and complex economic evaluation of 3D printer operation. Firstly, the principles of the FDM method are discussed, alongside with a review of its history. Furthermore, the work focuses on the comparison of important properties of selected materials used for printing. The author made measurements and evaluates important physical properties of selected materials with admixture of copper. Specifically, these are thermal, electrical and mechanical properties. The work describes methods used in the measurement and calculation of these variables with the aid of measuring devices support programs. In the last chapters, the author analyses the costs associated with the investment and operating costs of the Prusa i3 MK3S 3D printer and performs cost calculations for printing a product used in electronics, along with the comparison sold by the press of the manufactured product
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