Experimental investigation and prediction model for mechanical properties of copper-reinforced polylactic acid composites (Cu-PLA) using FDM-based 3D printing technique

The spokes of airless tire or non-pneumatic tire (NPT) are normally made with thermoplastic polyurethane (TPU), which is highly elastic material, to replace inflation pressure in conventional pneumatic tire. However there are limitation in designing of complex spoke geometries due to difficulty in manufacturing process, which normally involve molding process. Recently, the 3D printing technique has been improved and can be used to create highly complex geometries with wide range of materials. However the mechanical properties of printed spoke structure using 3D printing technique are still required to design and development of NPT. This research aim to study the mechanical properties of TPU while varying in printing conditions. The specimens were prepared from actual NPT spoke using waterjet cutting technique and 3D printing technique according to the testing standard ASTM D412 and D638, respectively. The tensile tests were performed on the specimens with corresponding crosshead speed. The testing speed of 3D printed specimen were also varied to 100 and 200 mm/min to study the effects of strain rate on mechanical properties. The stress-strain relationships were obtained from tensile testing and the important mechanical properties were then evaluated. The mechanical properties of specimens prepared from actual NPT spokes and 3D printed specimens were then compared. The ultimate stress of specimens prepared from actual NPT spokes in radial direction and 3D printed specimens with 100% infill were found to be 32.92 and 25.47 MPa, respectively, while the breaking strain were found to be 12.98 and 10.87, respectively. Thus, the information obtained from this research can be used to ensure the possibility in creating NPT spoke using 3D printing technique based on elastic material such as TPU.

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STRUCTURAL APPLICATION OF 3D PRINTING TECHNOLOGIES: MECHANICAL PROPERTIES OF PRINTED POLYMERIC MATERIALS / KONSTRUKCINIS 3D SPAUSDINIMO TECHNOLOGIJŲ TAIKYMAS: SPAUSDINTŲ POLIMERINIŲ MEDŽIAGŲ MECHANINĖS SAVYBĖS

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2018.6250 ◽

2018 ◽

Vol 10 (0) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Olena Shkundalova ◽

Arvydas Rimkus ◽

Viktor Gribniak

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Polymeric Materials ◽

Acrylonitrile Butadiene Styrene ◽

Tensile Tests ◽

Building Structures ◽

Printing Technique ◽

Printed Materials ◽

Printing Direction ◽

3D Printing Technique

Additive manufacturing and modern printing technologies using polymeric materials extend the limits of industrial production and encourage applying 3D printing technique in many fields. An item of any shape and size limited only by the printing pad of particular equipment can be reproduced from a variety of materials. Polymers is the object of this research. It is known that mechanical properties of the printed elements are closely related with the manufacturing technology and vary significantly depending on the chosen production parameters such as printing temperature, velocity, and infill density. Depending on the purpose, a particular type of polymer can be used in structural analysis. This work considers mechanical properties of four thermoplastic polymeric materials widely used for prototyping: polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), and polyethylene terephthalate (PETG). The study is focused on two fundamental mechanical characteristics, tensile strength and modulus of elasticity, of the printed material. Dumbbell-shaped samples were made of the PLA, ABS, HIPS and PETG polymers using 3D printing technique with the same filling density (≈ 20%) of the entry level. The tensile tests were carried out in Laboratory of Innovative Building Structures at Vilnius Gediminas Technical University. The predominant effect of the printing direction on the mechanical properties of the printed materials was demonstrated in this study. The corresponding experimental characteristics are presented in the manuscript. Santrauka Modernūs gamybos procesai ir spausdinimo technologijos, naudojant polimerines medžiagas, plečia pramoninės gamybos ribas bei skatina taikyti 3D spausdinimo technologijas daugelyje sričių. Tokios technologijos leidžia gaminti bet kokios formos elementus iš įvairių medžiagų, o jų dydį lemia tik naudojamos spausdinimo įrangos galimybės. Pagrindinis šio tyrimo objektas – polimerinės medžiagos. Spausdintų elementų iš polimerinių medžiagų mechaninės savybės glaudžiai siejamos su gamybos technologija ir gali stipriai varijuoti keičiant gamybos proceso parametrus – spausdinimo temperatūrą, greitį, užpildo tankį. Polimero tipas kartu su jo mechaninėmis savybėmis parenkamas atsižvelgiant į konstrukcinį uždavinį. Šiame darbe nagrinėjamos plačiai prototipų gamyboje taikomų termoplastinių polimerinių medžiagų – polietileno rūgšties (PLA), akrilonitrilo butadieno stireno (ABS), polistireno (HIPS) ir polietileno tereftalato (PETG) – mechaninės savybės. Tyrime dėmesys skiriamas dviem pagrindinėms mechaninėms medžiagų charakteristikoms – tempiamajam stipriui ir tamprumo moduliui. Taikant 3D spausdinimo technologiją buvo pagaminti kaulo formos bandiniai iš PLA, ABS, HIPS ir PETG medžiagų. Bandinių užpildo tankis siekė ≈ 20 % paviršiaus spausdinimo sluoksnio tankio. Elementų tempimo bandymai atlikti Inovatyvių statybinių konstrukcijų laboratorijoje Vilniaus Gedimino technikos universitete. Šiame tyrime buvo parodyta spausdinimo krypties įtaka spausdintų medžiagų mechaninėms savybėms. Taip pat pateiktos eksperimentiškai nustatytos polimerinių medžiagų mechaninės savybės.

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NUMERICAL AND MECHANICAL ANALYSES OF A 3D-PRINTED TITANIUM TRABECULAR DENTAL IMPLANT

Acta Polytechnica ◽

10.14311/ap.2017.57.0218 ◽

2017 ◽

Vol 57 (3) ◽

pp. 218-228

Author(s):

Luboš Řehounek ◽

Aleš Jíra

Keyword(s):

Mechanical Properties ◽

Numerical Model ◽

3D Printing ◽

Prostheses And Implants ◽

Trabecular Structure ◽

Compression Tests ◽

A Value ◽

Printing Technique ◽

3D Printed ◽

3D Printing Technique

The main focus of this paper is to investigate and describe a novel biomaterial structure. The trabecular structure has only recently been recognized as a viable alternative for prostheses and implants and seems to have very promising biocompatibility and mechanical properties. The 3D printing technique was used to create test specimens. These specimens were then tested by nanoindentation and tensile and compression tests. A numerical model was created and curve-fitted to represent the mechanical behavior of the trabecular structure. A significant reduction in the values of Young’s modulus <em>E</em> was observed. The values of <em>E</em> for conventional implant materials are approximately 110–120GPa and the trabecular structure reached a value just below 1GPa. The next effort will be to apply the model onto a real implant. It is the “four leaf clover” implant variant by authors F. Denk Jr., A. Jíra and F. Denk Sr.

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A New Polymer-Based Mechanical Metamaterial with Tailorable Large Negative Poisson’s Ratios

Polymers ◽

10.3390/polym12071492 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1492 ◽

Cited By ~ 1

Author(s):

Shanshi Gao ◽

Weidong Liu ◽

Liangchi Zhang ◽

Asit Kumar Gain

Keyword(s):

Mechanical Properties ◽

Cylindrical Shell ◽

Stress Concentration ◽

3D Printing ◽

Mechanical Metamaterials ◽

Printing Technique ◽

Poisson's Ratios ◽

Poisson’S Ratios ◽

3D Printing Technique ◽

Significant Attention

Mechanical metamaterials have attracted significant attention due to their programmable internal structure and extraordinary mechanical properties. However, most of them are still in their prototype stage without direct applications. This research developed an easy-to-use mechanical metamaterial with tailorable large negative Poisson’s ratios. This metamaterial was microstructural, with cylindrical-shell-based units and was manufactured by the 3D-printing technique. It was found numerically that the present metamaterial could achieve large negative Poisson’s ratios up to −1.618 under uniaxial tension and −1.657 under uniaxial compression, and the results of the following verification tests agreed with simulation findings. Moreover, stress concentration in this new metamaterial is much smaller than that in most of existing re-entrance metamaterials.

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Investigation of mechanical and fracture behavior of pure and carbon fiber reinforced ABS samples processed by fused filament fabrication process

Rapid Prototyping Journal ◽

10.1108/rpj-11-2020-0296 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Cem Boğa

Keyword(s):

Mechanical Properties ◽

Carbon Fiber ◽

3D Printing ◽

Mixed Mode ◽

Fracture Behavior ◽

Production Method ◽

Fused Filament Fabrication ◽

Content Type ◽

Printing Technique ◽

3D Printing Technique

Purpose Acrylonitrile butadiene styrene (ABS), as a light and high strength thermoplastic polymer, has found extensive applications in different industries. Fused filament fabrication, known as three-dimensional (3D) printing technique is considered a rapid prototyping technique that is frequently applied for production of samples of ABS material. Therefore, the purpose of this study is to investigate the mechanical and fracture behavior of such materials and the techniques to improve such properties. Design/methodology/approach Experimental and numerical analyses have been conducted to investigate the effects of internal architecture and chopped carbon fiber (CF) fillers on the mechanical properties and mixed mode fracture behavior of the ABS samples made by 3D printing technique. Four different filling types at 70% filling ratios have been used to produce tensile and special fracture test samples with pure and CF filled ABS filaments (CF-ABS) using 3D process. A special fixture has been developed to apply mixed mode loading on fracture samples, and finite element analyses have been conducted to determine the geometric function of such samples at different loading angles. Findings It has been determined that the printing pattern has a significant effect on the mechanical properties of the sample. The addition of 15% CF to pure ABS resulted in a significant increase in tensile strength of 46.02% for line filling type and 15.04% for hexagon filling type. It has been determined that as the loading angle increases from 0° to 90°, the KIC value decreases. The addition of 15% CF increased the KIC values for hexagonal and line filling type by 64.14% and 12.5%, respectively. Originality/value The damage that will occur in ABS samples produced in 3D printers depends on the type, amount, filling speed, filling type, filling ratio, filling direction and mechanical properties of the additives. All these features are clearly dependent on the production method. Even if the same additive is used, the production method difference shows different microstructural parameters, especially different mechanical properties.

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