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fused-deposition-modeling
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An Estimation Model for Computation and Control of Trajectory Coverage Error in Additive Manufacturing
, M.Sc. Thesis Sharif University of Technology ; Houshmand, Mahmood (Supervisor)
Abstract
During 1980s Additive Manufacturing technologies for the purpose of prototyping with fast and less expensive, under the name of Rapid Prototyping was invented. But nowadays under the vast progress made in this field, it possesses a notable place in different industries such as automobile manufacturing, aerospace, architecture, medicine and so on for part manufacturing. In all AM machines, the CAD model design part is manufactured by adding layered to each other. In this research, at first by explaining manufacturing process and current different technologies, the place of this manufacturing process in today and future industry, is analyzed. For discussing replacement of this method instead...
Fabrication of Micron Resolution Polymer Structures with Electrohydrodynamic Printing
, M.Sc. Thesis Sharif University of Technology ; Movahedi, Mohammad Reza (Supervisor)
Abstract
In recent years, additive manufacturing has been widely used in prototyping and production of industrial-commercial pieces. Additive manufacturing or three-dimensional (3D) printing is able to easily produce any piece for initial prototyping, no matter how complex it is. The fused deposition modeling (FDM) is a type of additive manufacturing process that produces the piece with the mechanism of feeding the PLA filament, then the molten polymer extrusion and depositing the fluid layer by layer with a high viscosity. Since the thickness of the layers is directly proportional to the diameter of the nozzle and the diameter of the used nozzles cannot be in the micron range (lower than 100...
Plasticity in polymeric honeycombs made by photo-polymerization and nozzle based 3D-printing
, Article Polymer Testing ; Volume 63 , 2017 , Pages 163-167 ; 01429418 (ISSN) ; Bagheri, R ; Avila Gray, L ; Altstädt, V ; Drechsler, K ; Sharif University of Technology
Abstract
Study of the plastic deformation in polymeric honeycombs can pave the way for understanding the deformation localization in more complex cellular structures, which have received progressive attention in the past few years. This study compares the strain localization in deforming honeycombs made by two cost-effective 3D-printing technologies. Hexagonal honeycombs and their unit cell models were 3D-printed by both PolyJet™, using a photo-crosslinkable polymer, and fused deposition modeling (FDM) using a thermoplastic material. The state of the art digital image correlation (DIC) technique was employed as the experimental route in order to calculate the strain field during the deformation of...
Experimental and Numerical Investigation on Mechanical Properties of Continuous Fiber Reinforced Parts Fabricated with FDM Additive Manufacturing Method
, M.Sc. Thesis Sharif University of Technology ; Yousefi, Reza (Supervisor) ; Kouchakzadeh, Mohammad Ali (Supervisor)
Abstract
With advancement of science of aircraft design and limitations of traditional manufacturing methods, using new ones in order to improve efficiency is needed. Among those methods to improve structure efficiency are weight reduction or increase in strength. Increasing strength-to-weight ratio and reduction of weight could be achieved by using composite materials and topology optimization respectively. Manufacturing such parts with efficient design using traditional methods is hard or impossible. Additive manufacturing as a new technology which is being developed every day, can be a big help to aerospace industry. Considering the importance of strength-to-weight ratio in aerospace industry and...
Fabrication and Characterization of Polylactic Acid-Mg Composites by 3d Printing Method for Biomedical Applications
, M.Sc. Thesis Sharif University of Technology ; Alizadeh, Reza (Supervisor) ; Abachi, Parvin (Supervisor)
Abstract
Polylactic acid (PLA) is considered as a great option to be employed as 3D porous scaffold in tissue engineering applications owing to its excellent biocompatibility and processability. However, relatively weak mechanical properties, low degradation rate and inappropriate biodegradability limit its extensive usage. In order to overcome the mentioned challenges, micrometric magnesium (Mg) particles were incorporated into the PLA matrix by the fused deposition modeling (FDM) technique. The effects of various Mg contents (i.e., 2, 4, 6, 8 and 10 wt%) on the mechanical, thermal, structural, wettability, rheological, biodegradability characteristics and cellular behavior of the 3D porous PLA-Mg...
Shear band propagation in honeycombs: numerical and experimental
, Article Rapid Prototyping Journal ; Volume 24, Issue 2 , 2018 , Pages 477-484 ; 13552546 (ISSN) ; Bagheri, R ; Altstadt, V ; Sharif University of Technology
Emerald Group Publishing Ltd
2018
Abstract
Purpose: Hexagonal honeycombs with meso-metric cell size show excellent load bearing and energy absorption potential, which make them attractive in many applications. However, owing to their bend-dominated structure, honeycombs are susceptible to deformation localization. The purpose of this study is to provide insight about shear band propagation in struts of 3D-printed honeycombs and its relation to the achieved macroscopic mechanical behavior. Design/methodology/approach: Hexagonal honeycombs and unit cell models are 3D-printed by fused deposition modeling (FDM). The samples are exposed to compression loading and digital image correlation technique and finite element analyses are...
An alternative additive manufacturing-based joining method to make Metal/Polymer hybrid structures
, Article Journal of Manufacturing Processes ; Volume 45 , 2019 , Pages 217-226 ; 15266125 (ISSN) ; Movahedi, M ; Tamizi, M ; Tartifzadeh, Z ; Alipour, S ; https://www.sciencedirect.com/science/article/abs/pii/S1526612519302087
Elsevier Ltd
2019
Abstract
Fused Deposition Modeling with Polypropylene filament was employed to make a lap joint between Polypropylene and pre-punched Al-Mg alloy sheets, in the form of bonds between the polymeric substrate and the additive part and mechanical lock between the additive part and aluminum base sheet. Effects of the joint interface area (hole diameter of 5–13 mm) and preheating of the substrates (room temperature, 50 and 90℃) were investigated on the mechanical properties of the joints. Peak load in the tensile-shear and cross-tension tests increased with enhancement of the joint interface area (up to ˜280 N and ˜160 N, respectively). Higher joint strength in the tensile-shear test compared to the...
Developing a novel technique for the fabrication of PLA-graphite composite filaments using FDM 3D printing process
, Article Ceramics International ; Volume 48, Issue 21 , 2022 , Pages 31850-31858 ; 02728842 (ISSN) ; Sayedain, S. S ; Tavangarifard, M ; Alizadeh, R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Developing a uniform polymer-based composite filament is a critical factor for a successful 3D printing process. In this regard, a novel technique for the fabrication of PLA-graphite filament with the potential to be applied to other PLA-based composite filaments was proposed and compared to the solvent casting method. This modified mixing technique involves partial dissolution of the PLA pellets surface by dichloromethane (DCM), which creates a sticky surface for the strong adhesion of reinforcement powders. The manufactured composite filament by this method exhibited excellent structural features, while the solvent casting method yielded a heterogeneous filament with a non-uniform diameter...
Additive manufacturing of bioactive glass biomaterials
, Article Methods ; Volume 208 , 2022 , Pages 75-91 ; 10462023 (ISSN) ; Alasvand, N ; Khodadadi, M ; Ghobadi, F ; Malekzadeh Kebria, M ; Brouki Milan, P ; Kargozar, S ; Baino, F ; Mobasheri, A ; Mozafari, M ; Sharif University of Technology
Academic Press Inc
2022
Abstract
Tissue engineering (TE) and regenerative medicine have held great promises for the repair and regeneration of damaged tissues and organs. Additive manufacturing has recently appeared as a versatile technology in TE strategies that enables the production of objects through layered printing. By applying 3D printing and bioprinting, it is now possible to make tissue-engineered constructs according to desired thickness, shape, and size that resemble the native structure of lost tissues. Up to now, several organic and inorganic materials were used as raw materials for 3D printing; bioactive glasses (BGs) are among the most hopeful substances regarding their excellent properties (e.g., bioactivity...
Improving mechanical properties and biocompatibility of 3D printed PLA by the addition of PEG and titanium particles, using a novel incorporation method
, Article Bioprinting ; Volume 27 , 2022 ; 24058866 (ISSN) ; Gerashi, E ; Zohrevand, M ; Zarei, M ; Sayedain, S. S ; Alizadeh, R ; Labbaf, S ; Atari, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Polylactic acid (PLA) scaffolds produced by the fused deposition modeling (FDM) method have biocompatibility, close Young's modulus to that of bone, and the ability to make complex shapes. However, PLA has some drawbacks like brittleness, inappropriate mechanical strength and hydrophobicity, and a low degradation rate. In this study, polyethylene glycol (PEG) (5 and 10 wt%) by solving method and titanium (Ti) particles (5 wt%) by two different methods were mixed with PLA to address the mentioned problems. Extruded filaments were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and fourier transform infrared (FTIR). Surface morphology of the produced filaments...