scholarly journals Influence of Geometric and Manufacturing Parameters on the Compressive Behavior of 3D Printed Polymer Lattice Structures

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1462
Author(s):  
Rafael Guerra Silva ◽  
Cristóbal Salinas Estay ◽  
Gustavo Morales Pavez ◽  
Jorge Zahr Viñuela ◽  
María Josefina Torres
Keyword(s):  
Mechanical Properties ◽  
Factorial Design ◽  
Fused Deposition Modeling ◽  
Digital Design ◽  
Fractional Factorial ◽  
Lattice Structures ◽  
Compressive Behavior ◽  
Fused Deposition ◽  
Custom Made ◽  
Manufacturing Parameters

Fused deposition modeling represents a flexible and relatively inexpensive alternative for the production of custom-made polymer lattices. However, its limited accuracy and resolution lead to geometric irregularities and poor mechanical properties when compared with the digital design. Although the link between geometric features and mechanical properties of lattices has been studied extensively, the role of manufacturing parameters has received little attention. Additionally, as the size of cells/struts nears the accuracy limit of the manufacturing process, the interaction between geometry and manufacturing parameters could be decisive. Hence, the influence of three geometric and two manufacturing parameters on the mechanical behavior was evaluated using a fractional factorial design of experiments. The compressive behavior of two miniature lattice structures, the truncated octahedron and cubic diamond, was evaluated, and multilinear regression models for the elastic modulus and plateau stress were developed. Cell size, unit cell type, and strut diameter had the largest impact on the mechanical properties, while the influence of feedstock material and layer thickness was very limited. Models based on factorial design, although limited in scope, could be an effective tool for the design of customized lattice structures.

Additive manufacturing and mechanical properties of lattice-curved structures

2019 ◽  
Vol 25 (5) ◽  
pp. 895-903 ◽  
Author(s):  
Enrique Cuan-Urquizo ◽  
Mario Martínez-Magallanes ◽  
Saúl E. Crespo-Sánchez ◽  
Alfonso Gómez-Espinosa ◽  
Oscar Olvera-Silva ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Structural Parameters ◽  
Structural Response ◽  
Layered Structures ◽  
Lattice Structures ◽  
Structure Property ◽  
Content Type ◽  
Fused Deposition ◽  
Curved Structures

Purpose The purpose of this paper is to study the feasibility of the fabrication of circle arc curved-layered structures via conventional fused deposition modeling (FDM) with three-axis machines and to identify the main structural parameters that have an influence on their mechanical properties. Design/methodology/approach Customized G-codes were generated via a script developed in MATLAB. The G-codes contain nozzle trajectories with displacements in the three axes simultaneously. Using these, the samples were fabricated with different porosities, and their influence on the mechanical responses evaluated via tensile testing. The load-displacement curves were analyzed to understand the structure-property relationship. Findings Circled arc curved-layered structures were successfully fabricated with conventional three-axis FDM machines. The response of these curved lattice structures under tensile loads was mapped to three main stages and deformation mechanisms, namely, straightening, stretching and fracture. The micro-structure formed by the transverse filaments affect the first stage significantly and the other two minimally. The main parameters that affect the structural response were found to be the transverse filaments, as these could behave as hinges, allowing the slide/rotation of adjacent layers and making the structure more shear sensitive. Research limitations/implications This paper was restricted to arc-curved samples fabricated with conventional three-axis FDM machines. Originality/value The FDM fabrication of curved-structures with controlled porosity and their relation to the resulting mechanical properties is presented here for the first time. The study of curved-lattice structures is of great relevance in various areas, such as biomedical, architecture and aerospace.

Multi-material, multi-technology FDM: exploring build process variations

2014 ◽  
Vol 20 (3) ◽  
pp. 236-244 ◽  
Author(s):  
David Espalin ◽  
Jorge Alberto Ramirez ◽  
Francisco Medina ◽  
Ryan Wicker
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Fused Deposition Modeling ◽  
Process Variation ◽  
Content Type ◽  
Layer Height ◽  
Fused Deposition ◽  
Custom Made ◽  
Road Width ◽  
Multiple Materials

Purpose – The purpose of this paper is to investigate a build process variation for fused deposition modeling (FDM) in which contours and rasters (also referred to as internal fill patterns) are built using different layer thicknesses and road widths. In particular, the paper examines the effect of the build process variation on surface roughness, production times and mechanical properties. Additionally, a unique FDM process was developed that enabled the deposition of discrete multiple materials at different layers and regions within layers. Design/methodology/approach – A multi-material, multi-technology FDM system was developed and constructed to enable the production of parts using either discrete multi-materials or the build process variation (variable layer thickness and road width). Two legacy FDM machines were modified and installed onto a single manufacturing system to allow the strategic, spatially controlled thermoplastic deposition with multiple extrusion nozzles of multiple materials during the same build. This automated process was enabled by the use of a build platform attached to a pneumatic slide that moved the platform between the two FDM systems, an overall control system, a central PC and a custom-made program (FDMotion) and graphic user interface. The term multi-technology FDM system used here implies the two FDM systems and the integration of these systems into a single manufacturing environment using the movable platform and associated hardware and software. Future work will integrate additional technologies within this system. Parts produced using the build process variation utilized internal roads with 1,524 μm road width and 508 μm layer height, while the contours used 254 μm road width and 127 μm layer height. Measurements were performed and compared to standard FDM parts that included surface roughness of planes at different inclinations, tensile testing and fabrication times. Findings – Results showed that when compared to the standard FDM process, the parts produced using the build process variation exhibited the same tensile properties as determined by a student's t-test (p-values > 0.05, μ1-μ2 = 0, n = 5). Surface roughness measurements revealed that the process variation resulted in surface roughness (Ra) improvements of 55, 43, 44 and 38 per cent for respective planes inclined at 10, 15, 30 and 45° from vertical. In addition, for a 50.8 × 50.8 mm square section (25.4 mm tall), the build process variation required a minimum of 2.8 hours to build, while the standard FDM process required 6.0 hours constituting a 53 per cent reduction in build time. Finally, several manufacturing demonstrations were performed including the fabrication of a discrete PC-ABS sandwich structure containing tetragonal truss core elements. Originality/value – This paper demonstrates a build strategy that varies contour and raster widths and layer thicknesses for FDM that can be used to improve surface roughness – a characteristic that has historically been in need of improvement – and reduce fabrication time while retaining mechanical properties.

scholarly journals FDM Layering Deposition Effects on Mechanical Response of TPU Lattice Structures

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5645
Author(s):  
Chiara Ursini ◽  
Luca Collini
Keyword(s):  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Mechanical Response ◽  
Lattice Structures ◽  
Fused Deposition ◽  
Functional Behavior ◽  
Unit Cells ◽  
Best Parameter ◽  
Materials Used ◽  
Parts Manufacturing

Nowadays, fused deposition modeling additive technology is becoming more and more popular in parts manufacturing due to its ability to reproduce complex geometries with many different thermoplastic materials, such as the TPU. On the other hand, objects obtained through this technology are mainly used for prototyping activities. For this reason, analyzing the functional behavior of FDM parts is still a topic of great interest. Many studies are conducted to broaden the spectrum of materials used to ensure an ever-increasing use of FDM in various production scenarios. In this study, the effects of several phenomena that influence the mechanical properties of printed lattice structures additively obtained by FDM are evaluated. Three different configurations of lattice structures with designs developed from unit cells were analyzed both experimentally and numerically. As the main result of the study, several parameters of the FDM process and their correlation were identified as possible detrimental factors of the mechanical properties by about 50% of the same parts used as isotropic cell solids. The best parameter configurations in terms of mechanical response were then highlighted by numerical analysis.

Mechanical characterization and finite element modeling of polylactic acid BCC-Z cellular lattice structures fabricated by fused deposition modeling

2016 ◽  
Vol 231 (11) ◽  
pp. 1995-2004 ◽  
Author(s):  
R Rezaei ◽  
MR Karamooz Ravari ◽  
M Badrossamay ◽  
M Kadkhodaei
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Polylactic Acid ◽  
Fused Deposition Modeling ◽  
Material Behavior ◽  
Lattice Structures ◽  
Stress Strain ◽  
Fused Deposition ◽  
Tension And Compression ◽  
Deposition Modeling

In recent years, cellular lattice structures are of interest due to their high strength in combination with low weight. They may be used in various areas such as aerospace and automotive industries. Accordingly, assessment of their manufacturability, repeatability and mechanical properties is very important. In this paper, these issues are investigated for Polylactic Acid cellular lattice structures fabricated by fused deposition modeling. To do so, some benchmarks are designed and fabricated to find suitable processing parameters as well as the structural dimensions. In addition, to evaluate the mechanical properties of the lattice’s material, a number of tension and compression specimens are fabricated and tested. The material’s stress–strain curves reveal non-linear behaviors. These curves are not coincided in tension and compression which shows an asymmetric material behavior. To characterize the fabricated cellular lattices, they are tested in compression, and the deformation mechanisms of the structures are analyzed. To investigate the correlation between the bulk material and the material of the ligaments, a solid finite element model is developed to predict the stress–strain response of the lattice. The obtained result shows a reasonably good correlation between the model and experiments.

scholarly journals The Influence of Raster Angle and Moisture Content on the Mechanical Properties of PLA Parts Produced by Fused Deposition Modeling

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 237
Author(s):  
Mohammed Algarni
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Fused Deposition ◽  
Raster Angle ◽  
Deposition Modeling ◽  
3D Printed ◽  
Printed Materials ◽  
Manufacturing Parameters

The additive manufacturing (AM) processes and technologies of 3D-printed materials and components using fused deposition modeling (FDM) are currently very popular and widely used for building parts and prototypes. Many manufacturing parameters can affect the strength and strain of the manufactured parts. The manufacturing parameters may be altered to reach an optimum setting for highly effective parts or components. This research studies the influence of the raster angle and the moisture content percentages on the mechanical properties of 3D printed polylactic acid (PLA) material. The three raster angles tested in this research were 0°, 45°, and 90°. The moisture content of the PLA material was altered to verify its effect on the mechanical properties. Twenty-seven specimens were subjected to tensile tests to examine the effect of different manufacturing parameters. The results show the specimens with a 90° raster angle and 10% moisture content have the optimum strength and strain mechanical properties.

scholarly journals 3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

2021 ◽  
Vol 11 (6) ◽  
pp. 2563
Author(s):  
Ivan Grgić ◽  
Vjekoslav Wertheimer ◽  
Mirko Karakašić ◽  
Željko Ivandić
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Biomechanical Properties ◽  
Testing Procedure ◽  
Laboratory Equipment ◽  
Fused Deposition ◽  
Custom Made ◽  
3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

scholarly journals Development of patient specific, realistic, and reusable video assisted thoracoscopic surgery simulator using 3D printing and pediatric computed tomography images

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dayeong Hong ◽  
HaeKang Kim ◽  
Taehun Kim ◽  
Yong-Hee Kim ◽  
Namkug Kim
Keyword(s):  
Computed Tomography ◽  
Mechanical Properties ◽  
Fused Deposition Modeling ◽  
Thoracoscopic Surgery ◽  
Clinical Situation ◽  
Patient Specific ◽  
Fused Deposition ◽  
Video Assisted ◽  
Computed Tomography Images ◽  
Video Assisted Thoracoscopic Surgery

AbstractHerein, realistic and reusable phantoms for simulation of pediatric lung video-assisted thoracoscopic surgery (VATS) were proposed and evaluated. 3D-printed phantoms for VATS were designed based on chest computed tomography (CT) data of a pediatric patient with esophageal atresia and tracheoesophageal fistula. Models reflecting the patient-specific structure were fabricated based on the CT images. Appropriate reusable design, realistic mechanical properties with various material types, and 3D printers (fused deposition modeling (FDM) and PolyJet printers) were used to represent the realistic anatomical structures. As a result, the phantom printed by PolyJet reflected closer mechanical properties than those of the FDM phantom. Accuracies (mean difference ± 95 confidence interval) of phantoms by FDM and PolyJet were 0.53 ± 0.46 and 0.98 ± 0.55 mm, respectively. Phantoms were used by surgeons for VATS training, which is considered more reflective of the clinical situation than the conventional simulation phantom. In conclusion, the patient-specific, realistic, and reusable VATS phantom provides a better understanding the complex anatomical structure of a patient and could be used as an educational phantom for esophageal structure replacement in VATS.

Physical property of 3D-printed sinusoidal pattern using shape memory TPU filament

2020 ◽  
Vol 90 (21-22) ◽  
pp. 2399-2410 ◽  
Author(s):  
Shahbaj Kabir ◽  
Hyelim Kim ◽  
Sunhee Lee
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Shape Memory ◽  
Fused Deposition Modeling ◽  
Loss Modulus ◽  
Thermoplastic Polyurethane ◽  
Heating Process ◽  
Fused Deposition ◽  
3D Printed ◽  
Sinusoidal Pattern

This study has investigated the physical properties of 3D-printable shape memory thermoplastic polyurethane (SMTPU) filament and its 3D-printed sinusoidal pattern obtained by fused deposition modeling (FDM) technology. To investigate 3D filaments, thermoplastic polyurethane (TPU) and SMTPU filament were examined by conducting infrared spectroscopy, x-ray diffraction (XRD), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC) and a tensile test. Then, to examine the 3D-printed sinusoidal samples, a sinusoidal pattern was developed and 3D-printed. Those samples went through a three-step heating process: (a) untreated state; (b) 5 min heating at 70°C, cooling for 30 min at room temperature; and (c) a repeat of step 2. The results obtained by the three different heating processes of the 3D-printed sinusoidal samples were examined by XRD, DMTA, DSC and the tensile test to obtain the effect of heating or annealing on the structural and mechanical properties. The results show significant changes in structure, crystallinity and thermal and mechanical properties of SMTPU 3D-printed samples due to the heating steps. XRD showed the increase in crystallinity with heating. In DMTA, storage modulus, loss modulus and the tan σ peak position also changed for various heating steps. The DSC result showed that the Tg for different steps of the SMTPU 3D-printed sample remained almost the same at around 51°C. The tensile property of the TPU 3D-printed sinusoidal sample decreased in terms of both load and elongation with increased heating processes, while for the SMTPU 3D-printed sinusoidal sample, the load decreased but elongation increased about 2.5 times.

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