A Customer-to-Manufacturer Design Model for Custom Compression Casts

2019 ◽  
Author(s):  
Yunbo Zhang ◽  
Tsz-Ho Kwok
Keyword(s):  
Optimization Problem ◽  
Three Dimensional ◽  
Human Model ◽  
Solid Model ◽  
3D Printer ◽  
Computational Framework ◽  
Mesh Surface ◽  
Interactive Tools ◽  
3D Printed ◽  
The Given

Abstract This paper presents a computational framework for designing and optimizing custom compression casts/braces. Different from the conventional cast/brace design, our framework generates custom casts/braces with fitness, lightweight, and good ventilation. The computational pipeline is an end-to-end solution, directly from customer to the manufacturer, which starts from a 3D scanned human model represented by mesh and ends with the 3D printed cast/brace. Our interactive tools allows users to define and edit the 3D curves on the mesh surface, and trim the mesh surface to form the cast/brace shape using the curves. These tools are efficient and simple to use, and also they enable designing the custom casts/braces fitting to the given human body. In order to reduce the weight and improve the ventilation, we adopt the topology optimization (TO) method to optimize the cast/brace design. We extend the existing three-dimensional (3D) TO method to the mesh surface by simplifying the optimization problem to a 2D problem. Therefore, the efficiency of the TO computation is improved significantly. After the optimized cast/brace design is obtained on the mesh surface, a solid model is generated by our design interface and then sent to a 3D printer for fabrication. Simulation results show that our method can better re-disturb the stresses compared with the conventional 3D TO.

scholarly journals Typography-Like 3D-Printed Templates for the Lithography-Free Fabrication of Microfluidic Chips

2019 ◽  
Vol 25 (1) ◽  
pp. 82-87
Author(s):  
Wenqiong Su ◽  
Yulong Li ◽  
Lulu Zhang ◽  
Jiahui Sun ◽  
Shuopeng Liu ◽  
...  
Keyword(s):  
Processing Time ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Cost Effective ◽  
Microfluidic Channels ◽  
3D Printer ◽  
Microfluidic Chips ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
3D Printed

Typography-like templates for polydimethylsiloxane (PDMS) microfluidic chips using a fused deposition modeling (FDM) three-dimensional (3D) printer are presented. This rapid and fast proposed scheme did not require complicated photolithographic fabrication facilities and could deliver resolutions of ~100 μm. Polylactic acid (PLA) was adopted as the material to generate the 3D-printed units, which were then carefully assembled on a glass substrate using a heat-melt-curd strategy. This craft of bonding offers a cost-effective way to design and modify the templates of microfluidic channels, thus reducing the processing time of microfluidic chips. Finally, a flexible microfluidic chip to be employed for cell-based drug screening was developed based on the modularized 3D-printed templates. The lithography-free, typography-like, 3D-printed templates create a modularized fabrication process and promote the prevalence of integrated microfluidic systems with minimal requirements and improved efficiency.

Assembly and Motion Simulation of Turntable of Drilling Rig Based on SolidWorks

2011 ◽  
Vol 474-476 ◽  
pp. 2253-2257
Author(s):  
Jiang Ping Wang ◽  
Qi Shang ◽  
Ze Fu Bao
Keyword(s):  
Three Dimensional ◽  
Solid Model ◽  
Motion Simulation ◽  
Assembly Sequence ◽  
Design Efficiency ◽  
Engineering Software ◽  
Overall Design ◽  
Drilling Rig ◽  
The Given ◽  
Dynamic Interference

Three-dimensional solid model of a turntable of a drilling rig is built utilizing the modeling functions of an engineering software SolidWorks. The virtual assembly for every components of the turntable is accomplished with the given assembly sequence in SolidWorks environment. The motion simulation and animation of simulation processes for the turntable under given conditions are carried out with module SOSMOSMotion of SolidWorks, and the dynamic interference check is also completed, so as to guarantee the correctness of the part design and improve the overall design efficiency, accuracy and intuitiveness. The study of assembly and motion simulation of the turntable based on SolidWorks can lay the foundation for communication and evaluation of design process as well as the manufacturing of the overall drilling rig.

scholarly journals Three-dimensional Printing Versus Conventional Machining in the Creation of a Meatal Urethral Dilator: a Cost and Mechanical Strength Analysis

2020 ◽  
Author(s):  
Michael Yue-Cheng Chen ◽  
Jacob Skewes ◽  
Ryan Daley ◽  
Maria Ann Woodruff ◽  
Nicholas John Rukin
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Strength Analysis ◽  
Fused Deposition Modelling ◽  
3D Printer ◽  
Current Time ◽  
Fused Deposition ◽  
3D Printed ◽  
Conventional Machining

Abstract BackgroundThree-dimensional (3D) printing is a promising technology but the limitations are often poorly understood. We compare different 3D printingmethods with conventional machining techniques in manufacturing meatal urethral dilators which were recently removed from the Australian market. MethodsA prototype dilator was 3D printed vertically orientated on a low cost fused deposition modelling (FDM) 3D printer in polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). It was also 3D printed horizontally orientated in ABS on a high-end FDM 3D printer with soluble support material, as well as on a SLS 3D printer in medical nylon. The dilator was also machined in stainless steel using a lathe. All dilators were tested mechanically in a custom rig by hanging calibrated weights from the handle until the dilator snapped. ResultsThe horizontally printed ABS dilator experienced failure at a greater load than the vertically printed PLA and ABS dilators respectively (503g vs 283g vs 163g, p < 0.001). The SLS nylon dilator and machined steel dilator did not fail. The steel dilator is most expensive with a quantity of five at 98 USD each, but this decreases to 30 USD each for a quantity of 1000. In contrast, the cost for the SLS dilator is 33 USD each for five and 27 USD each for 1000. ConclusionsAt the current time 3D printing is not a replacement for conventional manufacturing. 3D printing is best used for patient-specific parts, prototyping or manufacturing complex parts that have additional functionality that cannot otherwise beachieved.

Optimization-Based Prediction of Aiming and Kneeling Military Tasks Performed by a Soldier

2012 ◽  
Author(s):  
Mahdiar Hariri ◽  
Jasbir Arora ◽  
Karim Abdel-Malek
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Human Model ◽  
Ground Reaction Forces ◽  
Optimization Approach ◽  
Ground Contact ◽  
Digital Human Model ◽  
Reaction Forces ◽  
Digital Human ◽  
The Given

The objective of this study is to predict the “Aiming While Standing” and “Aiming While Kneeling” motion tasks for a soldier (human) using a full-body, three dimensional digital human model. The digital human is modeled as a 55 degree of freedom branched mechanism. Six degrees of freedom specify the global position and orientation of the coordinate frame attached to the pelvis of the digital human and 49 degrees of freedom represent the revolute joints which model the human joints and determine the kinematics of the entire digital human. Motion is generated by a multi-objective optimization approach minimizing the mechanical energy and joint discomfort simultaneously. A sequential quadratic programming (SQP) algorithm in SNOPT is used to solve the nonlinear optimization problem. The optimization problem is subject to constraints which represent the limitations of the environment, the digital human model and the motion task. Design variables are the joint angle profiles. All the forces, inertial, gravitational as well as external, are known, except the ground reaction forces. The feasibility of the generation of that arbitrary motion by using the given ground contact areas is ensured by using the well known Zero Moment Point (ZMP) constraint. During the kneeling motion, different parts of the body come in contact and lose contact with the ground which is modeled using a general approach. The ground reaction force on each transient ground contact area is determined using the equations of motion. It is assumed that enough friction exists that allow the human to generate reaction forces as determined by the ZMP constraint. Using these ground reaction forces, the required torques at all joints are calculated by the recursive Lagrangian formulation. Using the given method, we can predict realistic motions for the “Aiming While Standing” and “Aiming While Kneeling” tasks. The optimization approach is able to very well predict the “Natural Point of Aim” which is a well known concept for soldiers. In other words, the approach is able to predict the most comfortable final orientation of the feet on the ground for engaging a specific target. We also predict cases where the orientation of the soldier’s feet are enforced. Many virtual experiments have been conducted by changing the target location in the 3D space, changing the anthropometry of the soldier, adding armor to different joints, changing the variable parameters of the rifle, adding backpack and using different weapons.

scholarly journals Effect of infill density and pattern on the specific load capacity of FDM 3D-printed PLA multi-layer sandwich

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
József Dobos ◽  
Muammel M. Hanon ◽  
István Oldal
Keyword(s):  
Load Capacity ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Bending Test ◽  
Material Structure ◽  
Specific Load ◽  
3D Printed ◽  
Plastic Parts ◽  
The Given ◽  
Manufacturing Time

Abstract Three-dimensional (3D) printing settings allow the existence of differently filled sections together within a piece. That means the use of inhomogeneous internal material structure. Knowing the load capacity that 3D printed plastic parts can withstand leads to the reduction of the filling degree, thus the amount of the used material in certain places. This approach has two advantages during production: (i) less material use and (ii) reduced manufacturing time, both being cost-reducing factors. The present research aims to find the optimal proportions for fabricating a bending test piece with varying filling degrees. To achieve this goal, experimental tests were performed for obtaining tensile strength and modulus of elasticity using different pairs of infill density and pattern. This provided a basis for creating a working mechanical model based on accurate and realistic material properties. Hence, a series of virtual bending test experiments were conducted on a sandwich structure specimen employing Ansys Workbench software. By doing so, the optimal thickness (of the sandwich’s inner layer) with the highest specific load capacity for the given filling patterns and densities were determined. To the best of our knowledge, the current procedure of experiments and method of settings optimization were not discussed elsewhere.

scholarly journals Properties of 3D-printed wood sawdust-reinforced PLA composites

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5467-5480
Author(s):  
Nasir Narlıoğlu ◽  
Tufan Salan ◽  
Mehmet Hakkı Alma
Keyword(s):  
Mechanical Properties ◽  
Mechanical Test ◽  
Three Dimensional ◽  
Value Added ◽  
Polymeric Materials ◽  
Mechanical Tests ◽  
3D Printer ◽  
Pine Sawdust ◽  
Wood Sawdust ◽  
3D Printed

Thermal, morphological, and mechanical properties of three-dimensional (3D) printed polylactic acid (PLA) composites reinforced with different amounts of waste pine sawdust were investigated. To determine the mechanical properties of the obtained filaments, test samples were produced using a 3D printer according to the mechanical test standards. The filaments that were produced from blends that contained the wood sawdust at the highest level (20%) could be printed via a 3D printer without any problems. According to the results obtained from the mechanical tests, a decrease in the tensile strength values of the composites was observed with the addition of wood sawdust into the neat PLA polymer. On the other hand, it was determined that the flexural strength values of the wood sawdust/PLA composites significantly increased with the addition of the wood sawdust. It was concluded that the waste pine sawdust is a reasonable reinforcement material for the production of composite filament for 3D printing applications and it can be compatibly extruded with PLA polymer. Thus, sawdust can be used as a value-added waste source for the production of high-quality 3D polymeric materials.

scholarly journals Three-dimensional printing versus conventional machining in the creation of a meatal urethral dilator: a cost and mechanical strength analysis

2020 ◽  
Author(s):  
Michael Yue-Cheng Chen ◽  
Jacob Skewes ◽  
Ryan Daley ◽  
Maria Ann Woodruff ◽  
Nicholas John Rukin
Keyword(s):  
3D Printing ◽  
Low Cost ◽  
Three Dimensional ◽  
Patient Specific ◽  
Strength Analysis ◽  
3D Printer ◽  
Fused Deposition ◽  
3D Printed ◽  
The Cost ◽  
Conventional Machining

Abstract Background Three-dimensional (3D) printing is a promising technology in medicine. Low-cost 3D printing options are accessible but the limitations are often poorly understood. We aim to compare fused deposition modelling (FDM), the most common and low cost 3D printing technique, with selective laser sintering (SLS) and conventional machining techniques in manufacturing meatal urethral dilators which were recently removed from the Australian market.Methods A meatal urethral dilator was designed using computer-aided design (CAD). The dilator was 3D printed vertically orientated on a low cost FDM 3D printer in polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). It was also 3D printed horizontally orientated in ABS on a high-end FDM 3D printer with soluble support material, as well as on a SLS 3D printer in medical nylon. The dilator was also machined in medical stainless steel using a lathe. All dilators were tested mechanically in a custom rig by hanging calibrated weights from the handle until the dilator snapped.Results The horizontally printed ABS dilator experienced failure at a greater load than the vertically printed PLA and ABS dilators respectively (503g vs 283g vs 163g, p < 0.001). The SLS nylon dilator did not fail but began to bend and deformed at around 5,000g of pressure. The steel dilator did not bend even at 10,000g of pressure. The cost per dilator is highest for the steel dilator if assuming a low quantity of five at 98 USD, but this decreases to 30 USD for a quantity of 1000. In contrast, the cost for the SLS dilator is 33 USD for a quantity of five but relatively unchanged at 27 for a quantity of 1000.Conclusions SLS and conventional machining created clinically functional meatal dilators but low-cost FDM printing could not. We suggest that at the current time 3D printing is not a replacement for conventional manufacturing techniques which are still the most reliable way to produce large quantities of parts with a simple geometry such as the meatal dilator. 3D printing is best used for patient-specific parts, prototyping or manufacturing complex parts that have additional functionality that cannot be achieved with conventional machining methods.

Additive-Manufactured Organic Interposers

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
A. Roshanghias ◽  
M. Krivec ◽  
J. Bardong ◽  
A. Binder
Keyword(s):  
Flip Chip ◽  
Three Dimensional ◽  
Heterogeneous Integration ◽  
3D Printer ◽  
3D Integration ◽  
Wire Bond ◽  
3D Printers ◽  
Additional Costs ◽  
3D Printed ◽  
Flexible Die

Abstract The trend toward heterogeneous integration of optoelectronic, electronic, and micromechanical components favors three-dimensional (3D) integration in which the components are not arranged side-by-side but rather in vertical stacks. This presents a particular challenge due to the fact that the stacked components have different geometric dimensions, and their contact surfaces are also dissimilar. Therefore, an intermediate substrate, the so-called interposer, with different formats (i.e., flip-chip, wire-bond, and hybrid flip-chip/wire bond) comes into play. Currently, the interposers are mainly made of silicon or glass, which incur huge additional costs to the packaged components. In this study, the unique advantages of additive manufacturing (AM) are exploited to realize organic interposers. The proposed interposers provide easy signal probing and flexible die-to-board integration in lower costs without any lithography process, drilling, plating, or any waste. Accordingly, the two state-of-the-art 3D printers (i.e., a monomaterial 3D printer and a bimaterial 3D printer) were utilized for the manufacturing of the interposer parts. The complementary circuitry for vias and through-holes was facilitated by also additive technologies, i.e., 2D-inkjet printing and microdispensing. Moreover, and to manifest the unique possibilities within AM for the next generation of interposers, two examples for 3D-printed interposers with incorporated added-features, i.e., pillars for flip-chip bonding and cavities for face-up die-attachment were realized. The assemblies were consequently assessed by electrical examinations. Conclusively, the main opportunities and challenges toward the full implementation of AM technology for the fabrication of organic interposers with added-features such as integrated multipurpose vias were discussed. Based on the results obtained from this study, it was found that bimaterial 3D printer was more efficient and powerful for the construction of interposers.

scholarly journals Accuracy and Internal Fit of 3D printed Occlusal Splint, according to the printing position

2018 ◽  
Author(s):  
Mayra Torres Vasques ◽  
Dalva Cruz Laganá
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Digital Technologies ◽  
3D Printer ◽  
Occlusal Splint ◽  
Three Dimensional Printing ◽  
Dimensional Measurement ◽  
3D Printed ◽  
Internal Fit ◽  
Dimensional Printing

Understanding the importance of 3D printing strategies is a key to obtain predictable, optimized and consistent dental appliances using digital technologies. This study aims to present the influence of printing orientation on the intraoral fit of full arch coverage splints. Splints were designed for two patients using the CAD software and printed in a SLA 3D printer with different orientations (0, 30, and 90 degrees), and the internal fit was checked on patients’ mouth. Differen­ces between the fit of the splints were verified, with the worst results for 90º oriented splints, although more detailed studies are recommended by the authors. DESCRIPTORS | Three-Dimensional Printing; Accuracy; Dimensional Measurement; Occlusal Splint; Print Orientation.

scholarly journals Three-Dimensional Printing of Continuous Flax Fiber-Reinforced Thermoplastic Composites by Five-Axis Machine

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1678 ◽  
Author(s):  
Haiguang Zhang ◽  
Di Liu ◽  
Tinglong Huang ◽  
Qingxi Hu ◽  
Herfried Lammer
Keyword(s):  
Natural Fiber ◽  
Three Dimensional ◽  
Flax Fiber ◽  
Thermoplastic Composites ◽  
3D Printer ◽  
Fiber Reinforced ◽  
Fused Filament Fabrication ◽  
Reinforced Plastic ◽  
3D Printed ◽  
Five Axis

A method for printing continuous flax fiber-reinforced plastic (CFFRP) composite parts by five-axis three-dimensional (3D) printer, based on fused filament fabrication (FFF) technology, has been developed. FFF printed parts usually need supporting structures, have a stair step effect, and unfavorable mechanical properties. In order to address these deficiencies, continuous natural fiber prepreg filaments were first manufactured, followed by curved path planning for the model for generation of the G-code, and finally printed by a five-axis 3D printer. The surface quality of printed parts was greatly improved. The tensile strength and modulus of CFFRP increased by 89% and 73%, respectively, compared with polylactic acid (PLA) filaments. The flexural strength and modulus of the 3D-printed CFFRP specimens increased by 211% and 224%, respectively, compared with PLA specimens. The maximal curved bending force load and stiffness of the 3D-printed CFFRP specimens increased by 39% and 115%, respectively, compared with the flat slicing method. Advanced light structures, such as leaf springs, can be designed and manufactured by taking advantage of the favorable properties of these composites, which endow them with significant potential for application in the field of automobiles.

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