scholarly journals Investigation of Compressive Behavior of Pre-folded Thin-walled Column Fabricated by 3D Printing

2021 ◽  
Vol 6 (3) ◽  
pp. 543-560
Author(s):  
Farid Triawan ◽  
Elin Rachmawati ◽  
Bentang Arief Budiman ◽  
Djati Wibowo Djamari ◽  
Andy Saputro ◽  
...  
Keyword(s):  
3D Printing ◽  
Mechanical Behavior ◽  
Cross Section ◽  
Fused Deposition Modeling ◽  
Compressive Loading ◽  
Local Deformation ◽  
Element Analysis ◽  
Prosthetic Devices ◽  
Fused Deposition ◽  
Thin Walled

This paper reveals the mechanical behavior of thin-walled columns with pre-folded patterns subjected to compressive loading. The column specimens (Polylactic Acid) are fabricated using Fused Deposition Modeling 3D printer and subjected to quasi-static compressive loading to investigate their mechanical behavior (by modifying the specimens' cross-section patterns and folding angles). The column specimens are simulated by finite element analysis to understand how the stress distribution and local deformation affecting the stiffness, strength, and overall deformation. The experiments showed that introducing the pre-folded pattern in a thin-walled column with different cross-sections can dramatically lower its structural stiffness (85%) and compressive strength (69%), but increase its deformability (115%), which is good agreement with numerical simulation. The variation of cross-section patterns and pre-folding angle could effectively modify the compressive mechanical behavior. Moreover, the results demonstrate how the FDM 3D Printing method can be used in fabricating a thin-walled column with irregular shapes and then to modify its deformability. This finding can be useful for designing any complex structures requiring specific stiffness and deformation such as suspension devices, prosthetic devices in biomechanics, and robotic structures.

scholarly journals Mechanical behavior of beams with variable stiffness obtained by 3D printing

2021 ◽  
Vol 343 ◽  
pp. 08014
Author(s):  
Laszlo Racz ◽  
Mircea Cristian Dudescu
Keyword(s):  
3D Printing ◽  
Mechanical Behavior ◽  
Cross Section ◽  
Process Parameters ◽  
Fused Deposition Modeling ◽  
Cost Effective ◽  
Variable Stiffness ◽  
Constant Cross Section ◽  
Printing Process ◽  
Fused Deposition

Additive manufacturing or 3D printing gained a widespread popularity in recent years due to the ability of the method to manufacture components with high geometrical complexity. The most cost-effective process to manufacture plastic parts using 3D printing is the fused deposition modeling (FDM) method. Process parameters as the infill rates but also the printed pattern of different layers and their orientation have a significant influence on the mechanical properties of specimens fabricated by FDM. Controlling the process parameters is possible to generate materials with variable mechanical proprieties. The paper presents the analysis of a beam with constant cross-section but variable stiffness. Variable stiffness is achieved by changes in different cross-sections of the beam of the infill rates of the printing process. The mechanical behavior consisting of force-displacements curves is analyzed by three-point bending tests of variable stiffness samples and comparison with similar beams having constant infill rate. The results consist of E-modulus variation, maximum force and deflection curve. Analytical calculations and finite element analyses are employed to predict the mechanical behavior of the specimens printed with variable infill rate. The obtained results proved the concept of equal stress-beam with constant cross-section obtained by 3D printing process parameters variation.

Switchable Bistability in 3D Printed Shells With Bio-Inspired Architectures and Spatially Distributed Pre-Stress

2018 ◽  
Author(s):  
Karl Jin Ang ◽  
Katherine S. Riley ◽  
Jakob Faber ◽  
Andres F. Arrieta
Keyword(s):  
3D Printing ◽  
Room Temperature ◽  
Fused Deposition Modeling ◽  
Element Analysis ◽  
Fused Deposition ◽  
Spatially Distributed ◽  
Deposition Modeling ◽  
3D Printed ◽  
And Control ◽  
Careful Design

Using fused deposition modeling (FDM) 3D printing, we combine a bio-inspired bilayer architecture with distributed pre-stress and the shape memory behavior of polylactic acid (PLA) to manufacture shells with switchable bistability. These shells are stiff and monostable at room temperature, but become elastic and bistable with fast morphing when heated above their glass transition temperature. When cooled back down, the shells retain the configuration they were in at the elevated temperature and return to being stiff and monostable. These programmed deformations result from the careful design and control of how the filament is extruded by the printer and therefore, the resulting directional pre-stress. Parameter studies are presented on how to maximize the pre-stress for this application. The shells are analyzed using nonlinear finite element analysis. By leveraging the vast array of geometries accessible with 3D printing, this method can be extended to complex, multi-domain shells, including bio-inspired designs.

scholarly journals Research on improving the accuracy of FDM 3D printing process by using a new designed calibrating part

2019 ◽  
Vol 299 ◽  
pp. 01007
Author(s):  
Răzvan Păcurar ◽  
Valentin Buzilă ◽  
Ancuţa Păcurar ◽  
Eugen Guţiu ◽  
Sergiu Dan Stan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Analysis Method ◽  
Element Analysis ◽  
Printing Process ◽  
Software Application ◽  
Fused Deposition ◽  
Finite Element Analysis Method ◽  
Deposition Modeling

The article presents theoretical and experimental research methods that were used at the Technical University of Cluj-Napoca (TUCN) to improve the accuracy of Fused Deposition Modeling (FDM) 3D printing process. Finite element analysis method was successfully used for estimating the shrinkages of an original calibrating part that has been originally conceived for this purpose, this part being finally made using an original software application and FDM 3D printing equipment at TUC-N.

scholarly journals A Bio-Hygromorph Fabricated with Fish Swim Bladder Hydrogel and Wood Flour-Filled Polylactic Acid Scaffold by 3D Printing

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2896 ◽  
Author(s):  
Peng Li ◽  
Ling Pan ◽  
Dexi Liu ◽  
Yubo Tao ◽  
Sheldon Q. Shi
Keyword(s):  
3D Printing ◽  
Moisture Content ◽  
Polylactic Acid ◽  
Adaptive Systems ◽  
Fused Deposition Modeling ◽  
Moisture Absorption ◽  
Wood Flour ◽  
Swim Bladder ◽  
Element Analysis ◽  
Fused Deposition

Non-powered adaptive systems are attractive in the construction of environment actuators, meteorosensitive architectures, biomedical devices, and soft robotics. Combining hydrophilic materials and anisotropic structures to mimic self-morphing plant structures has been demonstrated as an effective approach to creating artificial hygromorphs. The convenience of 3D printing technologies in shaping programmable complex structures facilitates the imitation of complex anisotropic plant structures. In this research, we constructed a bio-hygromorph using fish swim bladder hydrogel as the hydrophilic material and wood flour-filled polylactic acid (WPLA) scaffold, which was printed with fused deposition modeling (FDM) 3D printing technology (3DP). The environmental benign bio-hygromorph displayed morphing abilities triggered by moisture content changes, as the fish swim bladder hydrogel swelled and shrunk during absorption and desorption cycles. The strain disproportion of the two-layered composite structure in the bio-hygromorph drove the bending deformation. Stress analyses performed with finite element analysis (FEA) also revealed the mechanism behind the moisture content driven morphing of the bio-hygromorph. Notably, the bio-hygromorph exhibited faster response times to moisture absorption than desorption, which may donate actuators’ different attributes in distinct moisture conditions.

scholarly journals Enhancing Structural Performance of Short Fiber Reinforced Objects through Customized Tool-Path

2020 ◽  
Vol 10 (22) ◽  
pp. 8168
Author(s):  
Jaeyoon Kim ◽  
Bruce S. Kang
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Behavior ◽  
Case Studies ◽  
Fused Deposition Modeling ◽  
Tool Path ◽  
Spur Gear ◽  
Fiber Reinforced ◽  
Printing Process ◽  
Fused Deposition

Fused deposition modeling (FDM) is one of the most common additive manufacturing (AM) technologies for thermoplastic materials. With the development of carbon fiber-reinforced polymer (CFRP) filament for FDM, AM parts with improved strength and functionality can be realized. CFRP is anisotropic material and its mechanical properties have been well studied, however, AM printing strategy for CFRP parts has not been developed. This paper proposes a systematic optimization of the FDM 3D printing process for CFRP. Starting with standard coupon specimen tests to obtain mechanical properties of CFRP, finite element analyses (FEA) were conducted to find principal directions of the AM part and utilized to determine fiber orientations. A specific tool-path algorithm has been developed to distribute fibers with the desired orientations. To predict/assess the mechanical behavior of the AM part, the 3D printing process was simulated to obtain the anisotropic mechanical behavior induced by the customized tool-path printing. Bolt hole plate and spur gear were selected as case studies. FE simulations and associated experiments were conducted to assess their performance. CFRP parts printed by the optimized tool-path shows about 8% higher stiffness than those printed at regular infill patterns. In summary, assisted by FEA, a customized 3D printing tool-path for CFRP has been developed with case studies to verify the proposed AM design optimization methodology for FDM.

Finite Element Simulation, Analysis and Research on the Influence of 3D Printing Parameters on Forming Precision

2019 ◽  
Vol 13 (4) ◽  
pp. 448-454
Author(s):  
Zhang Baoqing ◽  
Mohammad Imran Farid ◽  
Yu Shuo ◽  
Cao Cong ◽  
Shaoze Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Great Influence ◽  
Practical Significance ◽  
Element Analysis ◽  
Fused Deposition ◽  
Forming Precision ◽  
Printing Speed

Background: 3D printing technology is an emerging technology based on additive ideas. Desktop-level 3D printers molded by Fused Deposition Modeling (FDM) are widely used. However, their printing accuracy is relatively low accompanied by severe warpage, which limits its application scope and fields. Therefore, analysis of the cause of warpage in the printing process and optimization, has important practical significance for promoting the application of FDM printers. Methods: The goal of this work is to improve the forming precision of 3D prints, through the finite element analysis software ANSYS, utilizing the life and death component innovation and coupling the temperature field and stress field of printing speed, one of the key factors affecting the forming precision. After the calculation and analysis, the following conclusions can be drawn: In testing with other conditions unchanged, when the printing speed is gradually increased, the accuracy of the print is improved first and then decreased. This method provides a new way to analyze the influence of other factors on the forming accuracy and also provides a new way to get the best print parameters under the combined action of many factors. We reviewed several patents related to 3D printing, its optimization, formulations, precision and accuracy in respective field. Results: So, to achieve the best results, layer thickness has great influence on the molding precision. Finally, the results were obtained by finite element analysis, finding the best printing accuracy of the print parameters and verifying them by conducting actual printing. Conclusion: The research shows that the thickness of the layer has the greatest influence on the printing accuracy in the process parameters studied.

Biodegradable 3D Printed Polymer Microneedles for Transdermal Drug Delivery

2018 ◽  
Author(s):  
Michael A. Luzuriaga ◽  
Danielle R. Berry ◽  
John C. Reagan ◽  
Ronald A. Smaldone ◽  
Jeremiah J. Gassensmith
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Transdermal Drug Delivery ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Modeling Software ◽  
Deposition Modeling ◽  
3D Printed ◽  
Microfabrication Technique ◽  
Mechanical Strengths

Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers. We improved the feature size of the printed parts significantly by developing a post fabrication chemical etching protocol, which allowed us to access tip sizes as small as 1 μm. With 3D modeling software, various MN shapes were designed and printed rapidly with custom needle density, length, and shape. Scanning electron microscopy confirmed that our method resulted in needle tip sizes in the range of 1 – 55 µm, which could successfully penetrate and break off into porcine skin. We have also shown that these MNs have comparable mechanical strengths to currently fabricated MNs and we further demonstrated how the swellability of PLA can be exploited to load small molecule drugs and how its degradability in skin can release those small molecules over time.

scholarly journals 3D Printing of Mini Tablets for Pediatric Use

2021 ◽  
Vol 14 (2) ◽  
pp. 143
Author(s):  
Julius Krause ◽  
Laura Müller ◽  
Dorota Sarwinska ◽  
Anne Seidlitz ◽  
Malgorzata Sznitowska ◽  
...  
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Dosage Forms ◽  
Small Scale ◽  
Fused Deposition ◽  
On Demand ◽  
Pediatric Diseases ◽  
Deposition Modeling ◽  
Manufacturing Techniques ◽  
Pediatric Use

In the treatment of pediatric diseases, suitable dosages and dosage forms are often not available for an adequate therapy. The use of innovative additive manufacturing techniques offers the possibility of producing pediatric dosage forms. In this study, the production of mini tablets using fused deposition modeling (FDM)-based 3D printing was investigated. Two pediatric drugs, caffeine and propranolol hydrochloride, were successfully processed into filaments using hyprolose and hypromellose as polymers. Subsequently, mini tablets with diameters between 1.5 and 4.0 mm were printed and characterized using optical and thermal analysis methods. By varying the number of mini tablets applied and by varying the diameter, we were able to achieve different release behaviors. This work highlights the potential value of FDM 3D printing for the on-demand production of patient individualized, small-scale batches of pediatric dosage forms.

scholarly journals Mechanical Characterization and Thermodynamic Analysis of Laser-Polished Landscape Design Products Using 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2601
Author(s):  
Yue Ba ◽  
Yu Wen ◽  
Shibin Wu
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
High Surface ◽  
Landscape Design ◽  
Laser Polishing ◽  
Fused Deposition ◽  
Design Structure ◽  
3D Printed ◽  
Stability And Accuracy

Recent innovations in 3D printing technologies and processes have influenced how landscape products are designed, built, and developed. In landscape architecture, reduced-size models are 3D-printed to replicate full-size structures. However, high surface roughness usually occurs on the surfaces of such 3D-printed components, which requires additional post-treatment. In this work, we develop a new type of landscape design structure based on the fused deposition modeling (FDM) technique and present a laser polishing method for FDM-fabricated polylactic acid (PLA) mechanical components, whereby the surface roughness of the laser-polished surfaces is reduced from over Ra 15 µm to less than 0.25 µm. The detailed results of thermodynamics and microstructure evolution are further analyzed during laser polishing. The stability and accuracy of the results are evaluated based on the standard deviation. Additionally, the superior tensile and flexural properties are examined in the laser-polished layer, in which the ultimate tensile strength (UTS) is increased by up to 46.6% and the flexural strength is increased by up to 74.5% compared with the as-fabricated components. Finally, a real polished landscape model is simulated and optimized using a series of scales.

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