Balancing flexural strength and porosity in DLP-3D printing Al2O3 cores for hollow turbine blades

Abstract Traditionally, the technology used in the production of gas turbine blade castings characterized by a large number of technological conversions, high labor costs with a large amount of manual labor and the need to produce various types of complex and expensive equipment at different stages of production. This work aims to reduce the time and money spent on the manufacturing of ceramic shell shapes — a form suitable for the standard methods of precision casting by traditional heat-resistant nickel alloys. The proposed approached involves obtaining a shell shape with an internal core as a single, non-assembled product, without lengthy and time-consuming design and manufacturing processes involved in forming equipment for the production of castings based on smelted models. The proposed method is based on the use of 3D printing with refractory ceramic pastes. Using both uncooled and cooled blades as examples, models of casting molds were designed, technological processes were developed, and ceramic shell molds were manufactured. Experimental casting into a manufactured ceramic shell mold for an uncooled blade with a bandage shelf was performed and showed satisfactory results.

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Flexural strength of the various materials fabricated with 3d printing for implant 3unit bridges

Clinical Oral Implants Research ◽

10.1111/clr.222_13358 ◽

2018 ◽

Vol 29 ◽

pp. 337-337

Author(s):

Seong Kyun Kim ◽

Gangseok Park Park ◽

Joo-Hee Lee ◽

Seong Joo Heo ◽

Jai Young Koak

Keyword(s):

3D Printing ◽

Flexural Strength

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Hybrid Polymer Additive Manufacturing of a Darrieus Type Vertical Axis Wind Turbine Design to Improve Power Generation Efficiency

Volume 2: Advanced Manufacturing ◽

10.1115/imece2016-65910 ◽

2016 ◽

Author(s):

Sourabh Deshpande ◽

Nithin Rao ◽

Nitin Pradhan ◽

John L. Irwin

Keyword(s):

Power Generation ◽

Additive Manufacturing ◽

3D Printing ◽

Wind Turbine ◽

Turbine Blades ◽

Vertical Axis ◽

Blade Design ◽

Vertical Axis Wind Turbine ◽

Wind Turbine Blades ◽

3D Printed

Utilizing the advantages of additive manufacturing methods, redesigning, building and testing of an existing integral Savonius / Darrieus “Lenz2 Wing” style vertical axis wind turbine is predicted to improve power generation efficiency. The current wind turbine blades and supports made from aluminum plate and sheet are limiting the power generation due to the overall weight. The new design is predicted to increase power generation when compared to the current design due to the lightweight spiral Darrieus shaped hollow blade made possible by 3D printing, along with an internal Savonius blade made from aluminum sheet and traditional manufacturing techniques. The design constraints include 3D printing the turbine blades in a 0.4 × 0.4 × 0.3 m work envelope while using a Stratasys Fortus 400mc and thus the wind turbine blades are split into multiple parts with dovetail joint features, when bonded together result in a 1.2 m tall working prototype. Appropriate allowance in the mating dovetail joints are considered to facilitate the fit and bonding, as well as angle, size and placement of the dovetail to maximize strength. The spiral shape and Darrieus style cross section of the blade that provides the required lift enabling it to rotate from the static condition are oriented laterally for 3D printing to maximize strength. The bonding of the dovetail joints is carried out effectively using an acetone solution dip. The auxiliary components of the wind turbine which include the center support pole, top and bottom support, and center Savonius blades are manufactured using lightweight aluminum. Design features are included in the 3D printed blade parts so that they can be assembled with the aluminum parts in bolted connections. Analysis of the 3D CAD models show that the hybrid aluminum and hollow 3D printed blade construction provides a 50% cost savings over a 3D printed fully solid blade design while minimizing weight and maximizing the strength where necessary. Analysis of the redesign includes a detailed weight comparison, structural strength and the cost of production. Results include linear static finite element analysis for the strength in dovetail joint bonding and the aluminum to 3D printed connections. Additional data reported are the time frame for the design and manufacturing of the system, budget, and an operational analysis of the wind turbine with concern for safety. Results are analyzed to determine the advantages in utilizing a hybrid additive manufacturing and aluminum construction for producing a more efficient vertical axis wind turbine. Techniques used in the production of this type of wind turbine blade are planned to be utilized in similar applications such as a lightweight hovercraft propeller blade design to be tested in future research projects.

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Recycled Glass Fiber Composites from Wind Turbine Waste for 3D Printing Feedstock: Effects of Fiber Content and Interface on Mechanical Performance

Materials ◽

10.3390/ma12233929 ◽

2019 ◽

Vol 12 (23) ◽

pp. 3929 ◽

Cited By ~ 6

Author(s):

Amirmohammad Rahimizadeh ◽

Jordan Kalman ◽

Rodolphe Henri ◽

Kazem Fayazbakhsh ◽

Larry Lessard

Keyword(s):

Tensile Strength ◽

3D Printing ◽

Wind Turbine ◽

Glass Fiber ◽

Mechanical Performance ◽

Glass Fibers ◽

Turbine Blades ◽

3D Print ◽

Recycled Glass ◽

Recycled Fibers

This research validates the viability of a recycling and reusing process for end-of-life glass fiber reinforced wind turbine blades. Short glass fibers from scrap turbine blades are reclaimed and mixed with polylactic acid (PLA) through a double extrusion process to produce composite feedstock with recycled glass fibers for fused filament fabrication (FFF) 3D printing. Reinforced filaments with different fiber contents, as high as 25% by weight, are extruded and used to 3D print tensile specimens per ASTM D638-14. For 25 wt% reinforcement, the samples showed up to 74% increase in specific stiffness compared to pure PLA samples, while there was a reduction of 42% and 65% in specific tensile strength and failure strain, respectively. To capture the level of impregnation of the non-pyrolyzed recycled fibers and PLA, samples made from reinforced filaments with virgin and recycled fibers are fabricated and assessed in terms of mechanical properties and interface. For the composite specimens out of reinforced PLA with recycled glass fibers, it was found that the specific modulus and tensile strength are respectively 18% and 19% higher than those of samples reinforced with virgin glass fibers. The cause for this observation is mainly attributed to the fact that the surface of recycled fibers is partially covered with epoxy particles, a phenomenon that allows for favorable interactions between the molecules of PLA and epoxy, thus improving the interface bonding between the fibers and PLA.

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3D Printing Custom Bioactive and Absorbable Surgical Screws, Pins, and Bone Plates for Localized Drug Delivery

Journal of Functional Biomaterials ◽

10.3390/jfb10020017 ◽

2019 ◽

Vol 10 (2) ◽

pp. 17 ◽

Cited By ~ 15

Author(s):

Karthik Tappa ◽

Udayabhanu Jammalamadaka ◽

Jeffery Weisman ◽

David Ballard ◽

Dallas Wolford ◽

...

Keyword(s):

Drug Delivery ◽

3D Printing ◽

Flexural Strength ◽

Bone Plates ◽

Patient Specific ◽

Fixation Devices ◽

Significant Difference ◽

3D Printed ◽

Localized Drug Delivery ◽

Orthopedic Applications

Additive manufacturing has great potential for personalized medicine in osseous fixation surgery, including maxillofacial and orthopedic applications. The purpose of this study was to demonstrate 3D printing methods for the fabrication of patient-specific fixation implants that allow for localized drug delivery. 3D printing was used to fabricate gentamicin (GS) and methotrexate (MTX)-loaded fixation devices, including screws, pins, and bone plates. Scaffolds with different infill ratios of polylactic acid (PLA), both without drugs and impregnated with GS and MTX, were printed into cylindrical and rectangular-shaped constructs for compressive and flexural strength mechanical testing, respectively. Bland PLA constructs showed significantly higher flexural strength when printed in a Y axis at 100% infill compared to other axes and infill ratios; however, there was no significant difference in flexural strength between other axes and infill ratios. GS and MTX-impregnated constructs had significantly lower flexural and compressive strength as compared to the bland PLA constructs. GS-impregnated implants demonstrated bacterial inhibition in plate cultures. Similarly, MTX-impregnated implants demonstrated a cytotoxic effect in osteosarcoma assays. This proof of concept work shows the potential of developing 3D printed screws and plating materials with the requisite mechanical properties and orientations. Drug-impregnated implants were technically successful and had an anti-bacterial and chemotherapeutic effect, but drug addition significantly decreased the flexural and compressive strengths of the custom implants.

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Pembuatan dan Pengujian Panel Honeycomb Sandwich dengan Inti Berbentuk Gelombang Berbahan Komposit Serat Bambu

Jurnal Rekayasa Hijau ◽

10.26760/jrh.v5i2.165-177 ◽

2021 ◽

Vol 5 (2) ◽

pp. 165-177

Author(s):

Marsono Marsono ◽

Sarah Fauziyyah Hanifa ◽

Faizal Akbar

Keyword(s):

Flexural Strength ◽

Fiber Composite ◽

Turbine Blades ◽

Bamboo Fiber ◽

Bending Test ◽

Honeycomb Core ◽

Vertical Axis Wind Turbine ◽

Honeycomb Sandwich ◽

Core Height ◽

Strength And Stiffness

ABSTRAKDalam penelitian ini, komposit serat bambu dibuat menjadi panel struktur honeycomb sandwich dan diuji untuk mengukur kemungkinan pemanfaatannya sebagai bahan untuk membuat sudu turbin angin sumbu vertical. Honeycomb sanwich serat bambu yang dibuat memiliki inti (core) yang berbentuk gelombang sinus pada arah memanjang panel. Sebagai pengikat pada komposit ini digunakan resin polyester. Panel honeycomb sandwich yang dibuat memiliki panjang 500mm dan lebar 200mm, sedangkan tebal panel dibuat dengan dua variasi, yaitu dengan tinggi inti honeycomb 12mm dan 17mm. Panel honeycomb sandwich ini diuji dengan uji bending untuk mendapatkan angka kekuatan lentur (flexural strength) dan angka kekakuan (stiffness). Dari tiga panel yang dibuat identik untuk masih-masing ketinggian inti honeycomb, diperoleh angka kekuatan lentur dan kekakuan terbesar pada panel dengan ketinggian inti honeycomb17mm, yaitu dengan angka kekuatan lentur 0,91kg/mm2 dan angka kekakuan 11,35kg/mmKata kunci: honeycomb sandwich, komposit serat bambu,gelombang sinus,kekuatan lentur, kekakuan. ABSTRACTIn this research, bamboo fiber composite are made into honeycomb sandwich structure panel and to be tested for its ability as a material for vertical axis wind turbine blades. Bamboo fiber honeycomb sandwich had a sinusoidal-shaped core in the longitudinal direction of the panel. Polyester resin was used as a binder on this composite. The honeycomb panels that have been made have a length of 500mm and a width of 200mm. The thickness of the panels was made of two variations, which was has 12mm and 17mm honeycomb core-height. The honeycomb sandwich panel was tested by bending test to obtain flexural strength and stiffness. From the three panels that have been made in identical dimension for each honeycomb core-height, the highest flexural strength and stiffness was obtained in the specimen with the honeycomb core-height of 17mm, with a flexural strength of 0,91kg/mm2 and astiffness of 11,35kg/mm. Keywords: honeycomb sandwich, bamboo fiber composite, sinusoidal wave, flexurall strength, stiffness.

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Hardware Factors Influencing Interlayer Bonding Strength of Parts Obtained by Fused Filament Fabrication

10.20944/preprints201905.0108.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Vladimir E. Kuznetsov ◽

Azamat G. Tavitov ◽

Oleg D. Urzhumtcev

Keyword(s):

3D Printing ◽

Flexural Strength ◽

Layer Thickness ◽

Bonding Strength ◽

Cad Model ◽

Fused Filament Fabrication ◽

Three Point Bending ◽

Factors Influencing ◽

3D Printers ◽

Interlayer Bonding

Current paper investigates the influence of hardware setup and parameters of a 3D printing process based on fused filament fabrication (FFF) technology on resulting sample strength. Three-point bending of samples printed with long side oriented along Z axis was used as a measure of the interlayer bonding strength. The same CAD model was converted into NC-programs through same slicing software to be run on four different desktop FFF 3D printers, out of filament of same brand and color. Within all the printers same ranges of layer thickness values from 0.1 to 0.3 mm and feed rates from 25 to 75 mm/s were planned to be varied. All the machines demonstrated statistically almost identical values of maximum flexural strength, however the different machines exhibited maximum sample strength with different combinations of varied parameters. Among all the hardware factors observed, the most important was proved to be extruder type, direct or Bowden. This feature fundamentally changes the nature of studied parameters influence onto the resulting strength of the FFF process. For the extruders of Bowden type the length of flexible guiding tube is of great importance.All the machines demonstrated statistically almost identical values of maximum flexural strength, however the different machines exhibited maximum sample strength with different combinations of varied parameters. Among all the hardware factors observed, the most important was proved to be extruder type, direct or Bowden. This feature fundamentally changes the nature of studied parameters influence onto the resulting strength of the FFF process. For the extruders of Bowden type the length of flexible guiding tube is of great importance.

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Flexural strength of various kinds of the resin bridges fabricated with 3D printing

Journal of Dental Rehabilitation and Applied Science ◽

10.14368/jdras.2017.33.4.260 ◽

2017 ◽

Vol 33 (4) ◽

pp. 260-268 ◽

Cited By ~ 1

Author(s):

Sang-Mo Park ◽

Seong-Kyun Kim ◽

Ji-Man Park ◽

Jang-Hyun Kim ◽

Yoon-Tae Jeon ◽

...

Keyword(s):

3D Printing ◽

Flexural Strength

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Development of Dental Poly(methyl methacrylate)-Based Resin for Stereolithography Additive Manufacturing

Polymers ◽

10.3390/polym13244435 ◽

2021 ◽

Vol 13 (24) ◽

pp. 4435

Author(s):

Kentaro Hata ◽

Hiroshi Ikeda ◽

Yuki Nagamatsu ◽

Chihiro Masaki ◽

Ryuji Hosokawa ◽

...

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Flexural Strength ◽

Bond Strength ◽

Methyl Methacrylate ◽

Vickers Hardness ◽

Water Sorption ◽

Shear Bond Strength ◽

Dental Applications

Poly(methyl methacrylate) (PMMA) is widely used in dental applications. However, PMMA specialized for stereolithography (SLA) additive manufacturing (3D-printing) has not been developed yet. This study aims to develop a novel PMMA-based resin for SLA 3D-printing by mixing methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDMA), and PMMA powder in various mixing ratios. The printability and the viscosity of the PMMA-based resins were examined to determine their suitability for 3D-printing. The mechanical properties (flexural strength and Vickers hardness), shear bond strength, degree of conversion, physicochemical properties (water sorption and solubility), and cytotoxicity for L929 cells of the resulting resins were compared with those of three commercial resins: one self-cured resin and two 3D-print resins. EGDMA and PMMA were found to be essential components for SLA 3D-printing. The viscosity increased with PMMA content, while the mechanical properties improved as EGDMA content increased. The shear bond strength tended to decrease as EGDMA increased. Based on these characteristics, the optimal composition was determined to be 30% PMMA, 56% EGDMA, 14% MMA with flexural strength (84.6 ± 7.1 MPa), Vickers hardness (21.6 ± 1.9), and shear bond strength (10.5 ± 1.8 MPa) which were comparable to or higher than those of commercial resins. The resin’s degree of conversion (71.5 ± 0.7%), water sorption (19.7 ± 0.6 μg/mm3), solubility (below detection limit), and cell viability (80.7 ± 6.2% at day 10) were all acceptable for use in an oral environment. The printable PMMA-based resin is a potential candidate material for dental applications.

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Effect of Hybridization on Flexural Performance of Unidirectional and Bidirectional Composite Laminates under Ambient Temperature

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.56.16 ◽

2021 ◽

Vol 56 ◽

pp. 16-33

Author(s):

Getahun Aklilu ◽

Sarp Adali ◽

Glen Bright

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Carbon Fibre ◽

Composite Laminates ◽

Hybrid Composites ◽

Flexural Modulus ◽

Turbine Blades ◽

Carbon Fibres ◽

Wind Turbine Blades ◽

Flexural Performance

Abstract. Fibre Reinforced Plastic (FRP) materials are widely used in several key engineering applications such as ships, aircraft, wind turbine blades, helicopter blade, automobiles, and other transportation vehicles because of their mechanical properties and tailoring capabilities.Carbon and glass fibres are the most popular fibre reinforcements used for composite components. In the present study, two different stacking sequences, (0 degrees) and (0/90 degrees), are selected to study effect of fibre hybridization on flexural performance using three-point bending tests. Materials used are E-glass and T-300 carbon fibres in an epoxy matrix and the laminates were produced by resin transfer moulding methods. Fracture surfaces of composite laminates were examined using a scanning electron microscope. The results showed that the flexural strength, modulus and strain at failure of unidirectional and bidirectional composite laminates were strongly influenced by stacking sequences, fibre orientation and the hybrid ratio of the fibres. A higher flexural modulus was achieved when carbon fibres were placed on the compressive side. Hybrid specimens showed higher flexural strength and modulus by 21.08% and 145.39%, respectively, compared to the pure glass fibre reinforced laminates. On the other hand, flexural strength and modulus of hybrid specimen were less by 6.50% and 8.20%, respectively, as compared to carbon fibre reinforced specimens. Stacking sequences and hybrid ratio of glass/carbon fibre reinforced specimens were investigated with a view towards improving the mechanical properties of hybrid composites.

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