Search

Structural change can alter the energy absorption ability of constituent materials. Carbon organic framework (COF)-inspired structures printed with fusion deposition modeling (FDM) using polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) polymers are used to analyze the structural effect. Structures were characterized for specific energy absorption under static compression. The best structures from the static testing results were further characterized for dynamic compression using sinusoidal displacement to calculate the dynamic elastic recovery (DER), hysteresis work, and tan δ. Based on the results, the bending-dominated structure absorbed the highest energy, and the surface structure provided the best DER. The structure which failed by the pure collapsing of the layer showed the best specific values. The delamination of printed layers during loading reduced the performance of structures despite of the materials.

Structural change can alter the energy absorption ability of constituent materials. Carbon organic framework (COF)-inspired structures printed with fusion deposition modeling (FDM) using polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) polymers are used to analyze the structural effect. Structures were characterized for specific energy absorption under static compression. The best structures from the static testing results were further characterized for dynamic compression using sinusoidal displacement to calculate the dynamic elastic recovery (DER), hysteresis work, and tan δ. Based on the results, the bending-dominated structure absorbed the highest energy, and the surface structure provided the best DER. The structure which failed by the pure collapsing of the layer showed the best specific values. The delamination of printed layers during loading reduced the performance of structures despite of the materials. [ABSTRACT FROM AUTHOR]

This paper presents the design, development, and optimization of a 3D printed micro horizontal axis wind turbine blade made of PLA material. The objective of the study was to produce 100 watts of power for low-wind-speed applications. The design process involved the selection of SD7080 airfoil and the determination of the material properties of PLA and ABS. A structural analysis of the blade was carried out using ANSYS software under different wind speeds, and Taguchi's L16 orthogonal array was used for the experiments. The deformation and equivalent stress of the PLA material were identified, and the infill percentage and wind speed velocity were optimized using the moth-flame optimization (MFO) algorithm. The results demonstrate that PLA material has better structural characteristics compared to ABS material. The optimized parameters were used to fabricate the turbine blades using the fusion deposition modeling (FDM) technique, and they were tested in a wind tunnel. [ABSTRACT FROM AUTHOR]

Fused deposition modelling is a rapidly growing additive manufacturing technology due to its ability to build functional parts with complex geometries. The mechanical properties of a built part depend on several process parameters. The effect of wood content on the properties of 3D printed parts has been studied. Four types of filaments using poly(butylene succinate-co-adipate) (PBSA) with different reinforcement levels of Typha stem powder 0%, 5%, 10%, and 15% by weight were used for 3D printing. The density of the filaments and parts printed in this study increased with the Typha stem powder content. The thermal stability, mechanical performance, and viscoelastic properties of the different biocomposite filaments and 3D printed objects were analysed. The results show an increase in the crystallisation kinetics and a slight decrease in the thermal stability of the biomaterials. Compared to virgin PBSA FDM filaments, the PBSA biocomposite filament filled with Typha stem powder showed an increase in the tensile strength of the parts and specimens from 2.5 MPa to 8 MPa and in the modulus of elasticity from 160 MPa to 375 MPa, respectively, with additions of 5%, 10%, and 15% by mass. The addition of Typha stem fibres generated an increase in the elastic behaviour and relaxation time of the biomaterial structure, visualised by increases in the values of the viscosity components. The surface morphology reveals a decrease in the porosity of the printed samples. [ABSTRACT FROM AUTHOR]

The advancement of 3D-printing technology has ushered in a new era in the production of machine components, building materials, prototypes, and so on. In 3D-printing techniques, the infill reduces the amount of material used, thereby reducing the printing time and sustaining the aesthetics of the products. Infill patterns play a significant role in the property of the material. In this research, the mechanical properties of specimens are investigated for gyroid, rhombile, circular, truncated octahedron, and honeycomb infill structures (hexagonal). Additionally, the tensile properties of PLA 3D-printed objects concerning their infill pattern are demonstrated. The specimens were prepared with various infill patterns to determine the tensile properties. The fracture of the specimen was simulated and the maximum yield strengths for different infill structures and infill densities were determined. The results show the hexagonal pattern of infill holds remarkable mechanical properties compared with the other infill structures. Through the variation of infill density, the desired tensile strength of PLA can be obtained based on the applications and the optimal weight of the printed parts. [ABSTRACT FROM AUTHOR]

This paper presents the design, development, and optimization of a 3D printed micro horizontal axis wind turbine blade made of PLA material. The objective of the study was to produce 100 watts of power for low-wind-speed applications. The design process involved the selection of SD7080 airfoil and the determination of the material properties of PLA and ABS. A structural analysis of the blade was carried out using ANSYS software under different wind speeds, and Taguchi’s L16 orthogonal array was used for the experiments. The deformation and equivalent stress of the PLA material were identified, and the infill percentage and wind speed velocity were optimized using the moth-flame optimization (MFO) algorithm. The results demonstrate that PLA material has better structural characteristics compared to ABS material. The optimized parameters were used to fabricate the turbine blades using the fusion deposition modeling (FDM) technique, and they were tested in a wind tunnel.

Fused deposition modelling is a rapidly growing additive manufacturing technology due to its ability to build functional parts with complex geometries. The mechanical properties of a built part depend on several process parameters. The effect of wood content on the properties of 3D printed parts has been studied. Four types of filaments using poly(butylene succinate-co-adipate) (PBSA) with different reinforcement levels of Typha stem powder 0%, 5%, 10%, and 15% by weight were used for 3D printing. The density of the filaments and parts printed in this study increased with the Typha stem powder content. The thermal stability, mechanical performance, and viscoelastic properties of the different biocomposite filaments and 3D printed objects were analysed. The results show an increase in the crystallisation kinetics and a slight decrease in the thermal stability of the biomaterials. Compared to virgin PBSA FDM filaments, the PBSA biocomposite filament filled with Typha stem powder showed an increase in the tensile strength of the parts and specimens from 2.5 MPa to 8 MPa and in the modulus of elasticity from 160 MPa to 375 MPa, respectively, with additions of 5%, 10%, and 15% by mass. The addition of Typha stem fibres generated an increase in the elastic behaviour and relaxation time of the biomaterial structure, visualised by increases in the values of the viscosity components. The surface morphology reveals a decrease in the porosity of the printed samples.

The main goal of the present work was to investigate the influence of infill density (ID) on microstructure and flexural behavior of 3D printed parts by conducting three points bending test (3PBT). Flexural behavior of 3D printed parts is mainly dependent on ID which applied during printing. A thermoplastic of poly-lactic acid (PLA) was selected as material which can be best suitable for artificial tissue/bone engineering applications. Further, most of the artificial bones/tissues are subjected to fail due to bending load. Therefore, the effect of ID on the flexural strength of PLA (Bio-degradable) materials is important; which was addressed through this research work. Here, the PLA material was printed using fusion deposition modeling (FDM) by varying ID (40, 60, 80, and 100%). The 3D printed cylindrical specimen of 15 mm in diameter and 30 mm span was used. The bending responses in terms of bending stress-strain and bending force-deflection at each ID were investigated and reported. Furthermore, the fracture bending stress, fracture bending strain, flexural modulus, and stiffness of the printed sample were measured and correlated to the ID. The experimental result has shown that the bending characteristics influenced a strong correlation with ID percentage. The result suggested that the 80% ID was the optimum percentage which possessed considerable strength and toughness. Besides, the specimen surface morphology and the fracture topography were investigated and reported.

The advancement of 3D-printing technology has ushered in a new era in the production of machine components, building materials, prototypes, and so on. In 3D-printing techniques, the infill reduces the amount of material used, thereby reducing the printing time and sustaining the aesthetics of the products. Infill patterns play a significant role in the property of the material. In this research, the mechanical properties of specimens are investigated for gyroid, rhombile, circular, truncated octahedron, and honeycomb infill structures (hexagonal). Additionally, the tensile properties of PLA 3D-printed objects concerning their infill pattern are demonstrated. The specimens were prepared with various infill patterns to determine the tensile properties. The fracture of the specimen was simulated and the maximum yield strengths for different infill structures and infill densities were determined. The results show the hexagonal pattern of infill holds remarkable mechanical properties compared with the other infill structures. Through the variation of infill density, the desired tensile strength of PLA can be obtained based on the applications and the optimal weight of the printed parts.

3D printing, also known as additive manufacturing, is the process of creating a solid product by depositing layerby-layer a molten material in accordance with the parameters of the digitized model. The idea of 3D printing has come at the end of the 20th century. In the 1980s, it has started to compete with conventional manufacturing methods because of the extraordinary material efficiency, excellent surface finish, and one-step manufacturing provided. This technique has gradually been introduced to the fields of biomedicine, electronics, self-regeneration and biomimetics. However, it cannot control the dimensional changes caused by the deformation and the anisotropic behavior of the material. These difficulties are overcome by the 4D printing, which allows dynamic changes in the structures. The fourth parameter provides the products flexibility because, through an external stimulation, the smart materials used for the production can change the size, the properties and other parameters of the product. The smart or environmentally sensitive materials (metal alloys, polymers, ceramics, composites) can be activated by changes in the temperature, the water absorption, the electromagnetic and infrared radiation, the magnetic field, the current, the voltage, the changes of pH, etc. This smart behavior of the materials is important for the delivery of drugs, for sensors, in mobile electronics, for fashion products and other engineering objects. The unusual features of the 4D printing are based on the material shape memory effect and the ability of the materials to respond to external stimuli. [ABSTRACT FROM AUTHOR]

The main goal of the present work was to investigate the influence of infill density (ID) on microstructure and flexural behavior of 3D printed parts by conducting three points bending test (3PBT). Flexural behavior of 3D printed parts is mainly dependent on ID which applied during printing. A thermoplastic of poly-lactic acid (PLA) was selected as material which can be best suitable for artificial tissue/bone engineering applications. Further, most of the artificial bones/tissues are subjected to fail due to bending load. Therefore, the effect of ID on the flexural strength of PLA (Bio-degradable) materials is important; which was addressed through this research work. Here, the PLA material was printed using fusion deposition modeling (FDM) by varying ID (40, 60, 80, and 100%). The 3D printed cylindrical specimen of 15 mm in diameter and 30 mm span was used. The bending responses in terms of bending stress-strain and bending force-deflection at each ID were investigated and reported. Furthermore, the fracture bending stress, fracture bending strain, flexural modulus, and stiffness of the printed sample were measured and correlated to the ID. The experimental result has shown that the bending characteristics influenced a strong correlation with ID percentage. The result suggested that the 80% ID was the optimum percentage which possessed considerable strength and toughness. Besides, the specimen surface morphology and the fracture topography were investigated and reported. [ABSTRACT FROM AUTHOR]

Coronary artery abnormalities are described sporadically in dogs, most commonly with pulmonic stenosis. Computed tomographic angiography (CTA) allows non-invasive assessment of coronary anatomy. Three-dimensional (3D) models improve the understanding and visualization of spatially complex anatomy. The study objective was to evaluate coronary artery anomalies using CTA imaging and using rapid prototyping technology to create life-sized coronary artery models of these studies. Combined retrospective case and prospective pilot study. Inclusion criteria were dogs with reported coronary artery anomalies. The CTA data sets were imported into a medical imaging framework for the analysis of the coronary arteries and into a 3D-planning and printing software for creating printable 3D models. The 3D models were printed using fusion deposition modeling technology. Six male dogs with an R2A coronary artery anomaly and pulmonic stenosis diagnosed by CTA were included. Electrocardiogram (ECG)-gated CTA allowed better identification of anomalous coronary arteries than non-gated CTA. In all dogs, the right coronary artery had a smaller diameter than the left and the left coronary artery or its branch had a prepulmonic course. All ECG-gated studies were 3D printed while non-gated studies were not printable due to CTA artifacts. In dogs, CTA is effective for diagnosis of coronary artery anomalies. Printed 3D models of ECG-gated CTA studies were of excellent quality and allowed direct visualization of abnormal coronary artery anatomy. The usefulness of these models to improve the understanding of anomalous coronary artery anatomy could be evaluated in future studies. [ABSTRACT FROM AUTHOR]

Thermoplastic blends of polycaprolactone (PCL) and hydrolyzed collagen (HC) derived from the tannery industry were investigated to assess the feasibility of producing by conventional melting-based procedures biodegradable items for applications in agriculture and plant nurseries. The used HC was obtained by alkaline hydrolysis of the shavings of the tanning process. PCL/HC blends, with 10, 20 and 30 wt.% of HC, were processed by extrusion and compression molding, and characterized in terms of thermal, rheological, morphological and mechanical properties. In view of their possible applications in agriculture, phytotoxicity assays were carried out by using cress ( Lepidium sativum L.) germination test and growth analyses of lettuce plants ( Lactuca sativa L., cv Canasta), used as reference. Small pots were produced by fused deposition modeling (FDM) and their compostability was evaluated by the standard disintegration test UNI EN ISO 14045. The ultimate aerobic biodegradability of the blends was assessed by the standard UNI EN ISO 14855-1. PCL/HC blends were successfully processed by extrusion providing cohesive and flexible filaments suitable for the FMD 3D-printing. A decrease in the melt viscosity was observed with the addition of HC due to its plasticizing effect. The addition of HC led to a clear decrease of the tensile modulus and, with 30 wt.% HC, a break elongation higher than 600% as pure PCL. Despite the release in water of soluble salts, responsible of a moderate phytotoxicity assessed by L. sativum germination test, PCL/HC blends were not phytotoxic to the lettuce growth. Moreover, PCL/HC blends showed very high biodegradation rates in compost, even higher than cellulose. Composting trial performed under real conditions also confirmed the biodegradability of these blends, showing complete disintegration of the produced 3D printed pots in just 30 days. [ABSTRACT FROM AUTHOR]