scholarly journals Predicting precision grip grasp locations on three-dimensional objects

2018 ◽  
Author(s):  
Lina K. Klein ◽  
Guido Maiello ◽  
Vivian C. Paulun ◽  
Roland W. Fleming
Keyword(s):  
Mass Distribution ◽  
Precision Grip ◽  
Three Dimensional ◽  
Behavioral Data ◽  
Three Dimensional Objects ◽  
3D Objects ◽  
Contact Points ◽  
Potential Contact ◽  
3D Printed ◽  
Precision Grasping

AbstractWe rarely experience difficulty picking up objects, yet of all potential contact points on the surface, only a small proportion yield effective grasps. Here, we present extensive behavioral data alongside a normative model that correctly predicts human precision grasping of unfamiliar 3D objects. We tracked participants’ forefinger and thumb as they picked up objects of 10 wood and brass cubes configured to tease apart effects of shape, weight, orientation, and mass distribution. Grasps were highly systematic and consistent across repetitions and participants. We employed these data to construct a model which combines five cost functions related to force closure, torque, natural grasp axis, grasp aperture, and visibility. Even without free parameters, the model predicts individual grasps almost as well as different individuals predict one another’s, but fitting weights reveals the relative importance of the different constraints. The model also accurately predicts human grasps on novel 3D-printed objects with more naturalistic geometries and is robust to perturbations in its key parameters. Together, the findings provide a unified account of how we successfully grasp objects of different 3D shape, orientation, mass, and mass distribution.Author SummaryA model based on extensive behavioral data unifies the varied and fragmented literature on human grasp selection by correctly predicting human grasps across a wide variety of conditions.

Welding Technology in Additive Manufacturing Processes of 3D Objects

2017 ◽  
Vol 906 ◽  
pp. 121-130 ◽  
Author(s):  
V. Korzhyk ◽  
V. Khaskin ◽  
O. Voitenko ◽  
Volodymyr Sydorets ◽  
O. Dolianovskaia
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Simultaneous Increase ◽  
Manufacturing Cost ◽  
Three Dimensional Objects ◽  
3D Objects ◽  
Input Quality ◽  
Welding Technology ◽  
Metal Volume ◽  
Increase In Productivity

Using of welding technologies to produce metal volume objects allows considerable lowering of their manufacturing cost at simultaneous increase in productivity, compared to SLS-and SLM-processes. The most perspective welding technology of additive manufacturing of three-dimensional objects is plasma-arc technology with application of wires or powders. It allows creating at comparatively low heat input quality volumetric products with wall thickness from 3 to 50 mm from alloys based on Fe, Ni, Co, Cu, Ti, Al, as well as composite materials, containing refractory components.

scholarly journals Research and development of decision-making methods for creating 3d objects in mechanical engineering

2018 ◽  
Vol 224 ◽  
pp. 02002
Author(s):  
Alan Kumaritov ◽  
Ekaterina Sokolova
Keyword(s):  
Decision Making ◽  
Research And Development ◽  
Mechanical Engineering ◽  
Three Dimensional ◽  
Absolute Truth ◽  
Three Dimensional Objects ◽  
3D Objects ◽  
Truth Value

The analysis of the criterion of integral proximity of a clear / fuzzy truth value to the value of absolute truth is carried out in this work. Confirmation of the possibility of using algorithms to create three-dimensional objects in engineering.

scholarly journals Predicting precision grip grasp locations on three-dimensional objects

2020 ◽  
Vol 16 (8) ◽  
pp. e1008081 ◽  
Author(s):  
Lina K. Klein ◽  
Guido Maiello ◽  
Vivian C. Paulun ◽  
Roland W. Fleming
Keyword(s):  
Precision Grip ◽  
Three Dimensional ◽  
Three Dimensional Objects

A Three-Dimensional Printed, Nonassembly, Passive Dynamic Walking Toy: Design and Analysis

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Christian L. Treviño ◽  
Joseph D. Galloway ◽  
Pranav A. Bhounsule
Keyword(s):  
3D Printing ◽  
Mass Distribution ◽  
Three Dimensional ◽  
Mass Distributions ◽  
Wide Range ◽  
Walking Motion ◽  
Wood Carving ◽  
3D Printed ◽  
Kinematic Mechanisms ◽  
Toy Design

In this paper, we present the redesign and analysis of a century old walking toy. Historically, the toy is made up of two wooden pieces including a rear leg and a front leg and body (as a single piece) that are attached to each other by means of a pin joint. When the toy is placed on a ramp and given a slight perturbation, it ambles downhill powered only by gravity. Before the toy can walk successfully, it needs careful tuning of its geometry and mass distribution. The traditional technique of manual wood carving offers very limited flexibility to tune the mass distribution and geometry. We have re-engineered the toy to be three-dimensional (3D) printed as a single integrated assembly that includes a pin joint and the two legs. After 3D printing, we have to manually break-off the weakly held support material to allow movement of the pin joint. It took us 6 iterations to progressively tune the leg geometry, mass distribution, and hinge joint tolerances to create our most successful working prototype. The final 3D printed toy needs minimal postprocessing and walks reliably on a 7.87 deg downhill ramp. Next, we created a computer model of the toy to explain its motion and stability. Parameter studies reveal that the toy exhibits stable walking motion for a fairly wide range of mass distributions. Although 3D printing has been used to create nonassembly articulated kinematic mechanisms, this is the first study that shows that it is possible to create dynamics-based nonassembly mechanisms such as walking toys.

scholarly journals Conventional Construction and 3D Printing: A Comparison Study on Material Cost in Jordan

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Rawan Allouzi ◽  
Wael Al-Azhari ◽  
Rabab Allouzi
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Environmental Parameters ◽  
Structural Features ◽  
Precise Description ◽  
3D Objects ◽  
3D Printed ◽  
Computer Controlled ◽  
Printing Processes ◽  
The Impact

Three-dimensional (3D) printing is a procedure used to create 3D objects in which consecutive layers of a material are computer-controlled produced. Such objects can be constructed in any shape using digital model data. First, this paper presents a state-of-the-art review of the advances in 3D printing processes of construction. Then, the architectural, economical, environmental, and structural features of 3D printing are introduced. Examples of 3D printed structures are presented, and the construction challenges facing Jordan, that encouraged this study, are stated. Finally, a precise description regarding the impact of 3D printing is provided by comparing conventional construction data of Ras Alain Multipurpose Hall in Jordan and the expected data if the same building has been built using 3D printing. The suggested model is generated using Revit software. As a result of this study, an understanding of 3D printing procedure, mechanism of action, and its impact on the future of construction and architecture through economical, structural, and environmental parameters is achieved. This leads to encourage engineers and contractors to take this subject into account for construction in Jordan.

scholarly journals Optimization of placement in the tasks of rapid prototyping and manufacturing of volumetric parts based on additive technologies

2020 ◽  
Author(s):  
M.A. Verkhoturov ◽  
G.N. Verkhoturova ◽  
R.R. Yagudin ◽  
K.V. Danilov ◽  
R.R. Karimov ◽  
...  
Keyword(s):  
Synthesis Method ◽  
Three Dimensional ◽  
Additive Technologies ◽  
Small Scale ◽  
Scale Production ◽  
Three Dimensional Objects ◽  
3D Objects ◽  
Algorithmic Solution ◽  
Rapid Prototyping And Manufacturing ◽  
Modelling Problems

The problem of optimizing the life cycle of complex three-dimensional objects in small-scale production is considered. Additive technologies and optimization algorithms for the placement of three-dimensional objects are considered as technologies to solve this problem. Using the multilevel synthesis method can significantly reduce the time for prototyping new products. It should be noted that since several independent parts can be manufactured at the same time, this problem belongs to the class of optimization geometric modelling problems, namely, the problem of three-dimensional irregular placement. An algorithmic solution is proposed for the most complex task - placing 3D objects in a container. The results of the analysis of the effectiveness of the proposed algorithms are discussed.

scholarly journals APPLICATIONS OF 3D PRINTING TECHNOLOGIES IN THE GARMENT INDUSTRY

2018 ◽  
Vol 16 (2) ◽  
pp. 104-107
Author(s):  
Veronica Verlan ◽  
Marcela Irovan
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Manufacturing Process ◽  
New Technology ◽  
Three Dimensional ◽  
Advanced Technology ◽  
Innovative Technologies ◽  
Three Dimensional Objects ◽  
Aesthetic Appearance ◽  
3D Printed

The usage of innovative technologies has become one of the most widespread ways of diversifying the current supply of clothing and footwear products. Therefore, using the 3D printing technologies in the garment production is a remarkable example of the symbiosis of creativity and technology, which creates unusual and fashionable clothing pieces. Although the 3D printing technology is a relatively new technology and allows creating unique garments it must not neglect important features of clothing products such as cost-accessibility, comfort and aesthetic appearance. The research on these aspects is prior to implement this technology in the manufacturing process. The study includes the analysis of the current 3D printing technologies which are used for obtaining three-dimensional objects, the current directions of implementing this technology in the industry, as well as the opportunities of applying this technology in the process of clothing’s creation. Therefore, this paper concludes the study with the creation of a clothing product – a blouse for women, which is including a 3D printed part confirming this way the possibility of creation of clothing products, which would integrate innovative elements which were obtained by implementing the advanced technology of additive manufacturing.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Use of Three-dimensional Printing in the Development of Optimal Cardiac CT Scanning Protocols

2020 ◽  
Vol 16 (8) ◽  
pp. 967-977
Author(s):  
Zhonghua Sun
Keyword(s):  
Cardiovascular Disease ◽  
Cardiac Computed Tomography ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Aortic Diseases ◽  
Clinical Value ◽  
Three Dimensional Printing ◽  
Doctor Patient Communication ◽  
Medical Education And Training ◽  
3D Printed

Three-dimensional (3D) printing is increasingly used in medical applications with most of the studies focusing on its applications in medical education and training, pre-surgical planning and simulation, and doctor-patient communication. An emerging area of utilising 3D printed models lies in the development of cardiac computed tomography (CT) protocols for visualisation and detection of cardiovascular disease. Specifically, 3D printed heart and cardiovascular models have shown potential value in the evaluation of coronary plaques and coronary stents, aortic diseases and detection of pulmonary embolism. This review article provides an overview of the clinical value of 3D printed models in these areas with regard to the development of optimal CT scanning protocols for both diagnostic evaluation of cardiovascular disease and reduction of radiation dose. The expected outcomes are to encourage further research towards this direction.

Investigation of the Static Behavior and Failure Mechanisms of a 3D Printed Bio-Based Sandwich with Auxetic Core

2020 ◽  
Vol 12 (05) ◽  
pp. 2050051
Author(s):  
Khawla Essassi ◽  
Jean-Luc Rebiere ◽  
Abderrahim El Mahi ◽  
Mohamed Amine Ben Souf ◽  
Anas Bouguecha ◽  
...  
Keyword(s):  
Failure Mechanisms ◽  
Three Dimensional ◽  
Acoustic Emissions ◽  
Shear Stiffness ◽  
Tensile Tests ◽  
Sandwich Composite ◽  
Static Behavior ◽  
Flax Fibers ◽  
Data Points ◽  
3D Printed

In this research contribution, the static behavior and failure mechanisms are developed for a three-dimensional (3D) printed dogbone, auxetic structure and sandwich composite using acoustic emissions (AEs). The skins, core and whole sandwich are manufactured using the same bio-based material which is polylactic acid reinforced with micro-flax fibers. Tensile tests are conducted on the skins and the core while bending tests are conducted on the sandwich composite. Those tests are carried out on four different auxetic densities in order to investigate their effect on the mechanical and damage properties of the materials. To monitor the invisible damage and damage propagation, a highly sensitive AE testing method is used. It is found that the sandwich with high core density displays advanced mechanical properties in terms of bending stiffness, shear stiffness, facing bending stress and core shear stress. In addition, the AE data points during testing present an amplitude range of 40–85[Formula: see text]dB that characterizes visible and invisible damage up to failure.

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