scholarly journals Review of Peridynamics: Theory, Applications, and Future Perspectives

2021 ◽  
Vol 67 (12) ◽  
pp. 666-681
Author(s):  
Gábor Ladányi ◽  
Viktor Gonda
Keyword(s):  
Time Scales ◽  
Large Deformations ◽  
High Efficiency ◽  
Research Work ◽  
Modelling And Simulation ◽  
Future Perspectives ◽  
Local Method ◽  
Key Concepts ◽  
Non Local ◽  
Number Of Publications

The modelling and simulation of material degradations, particularly fractures in solids of different lengths and time scales, remains challenging despite the numerous approaches that have been developed. In this review, the focus is set on research work concerned with a very promising non-local method: peridynamic modelling. With this approach, continuous phenomena may be described, and the complete evolution (i.e., initiation, propagation, branching, or coalescence) of cracks and other discontinuities can be followed in solids in an integrated framework. Evaluating the large number of publications on this topic, the authors chose to present concisely the key concepts, applications, and results in identifying possible future paths: the incorporation of mechanics of large deformations and material nonlinearities, and the development of high-efficiency peridynamic solvers. This review does not intersect with recent relevant reviews, which reflects its significance to readers.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

scholarly journals Friction-Induced Recycling Process for User-Specific Semi-Finished Product Production

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 663
Author(s):  
Thomas Borgert ◽  
Werner Homberg
Keyword(s):  
High Efficiency ◽  
Research Work ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Efficient Production ◽  
Secondary Aluminum ◽  
Shape Accuracy ◽  
Aluminum Chips ◽  
Spinning Process ◽  
Complex Parts

Modern forming processes often allow today the efficient production of complex parts. In order to increase the sustainability of forming processes it would be favorable if the forming of workpieces becomes possible using production waste. At the Chair of Forming and Machining Technology of the Paderborn University (LUF) research is presently conducted with the overall goal to produce workpieces directly from secondary aluminum (e.g., powder and chips). Therefore, friction-based forming processes like friction spinning (or cognate processes) are used due to their high efficiency. As a pre-step, the production of semi-finished parts was the subject of accorded research work at the LUF. Therefore, a friction-based hot extrusion process was used for the full recycling or rework of aluminum chips into profiles. Investigations of the recycled semi-finished products show that they are comparable to conventionally produced semi-finished products in terms of dimensional stability and shape accuracy. An analysis of the mechanical properties of hardness and tensile strength shows that a final product with good and homogeneously distributed properties can be produced. Furthermore, significant correlations to the friction spinning process could be found that are useful for the above-mentioned direct part production from secondary aluminum.

scholarly journals Heating an electric car with a biofuel operated heater during cold seasons – design, application and test

ACTA IMEKO ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 48 ◽  
Author(s):  
Christian Riess ◽  
Michael Simon Josef Walter ◽  
Stefan Weiherer ◽  
Tiffany Haas ◽  
Sebastian Haas ◽  
...  
Keyword(s):  
Structural Changes ◽  
High Efficiency ◽  
Technological Development ◽  
Research Work ◽  
Heating System ◽  
Passenger Compartment ◽  
External Energy ◽  
Cold Temperatures ◽  
Electric Car ◽  
Drive Systems

The automotive industry is currently undergoing far-reaching structural changes. Automobile manufacturers are pursuing intensive scientific research and technological development in the field of alternative drive systems, such as electric powertrains. If electric car batteries are charged with regenerative generated electricity, their emission output is zero (from a well-to-wheel view). Furthermore, electric drives have very high efficiency. At cold temperatures, however, the battery power drops due to energy-intensive loads, such as the heating of the passenger compartment, and this consequently reduces the range dramatically. Therefore, the focus of this research work is external energy supply for the required heat capacity. The auxiliary energy may be generated by renewable energy technologies in order to further improve the CO<sub>2</sub> balance of electric vehicles. The paper deals with the design, application, and testing of a biofuel-operated heater to heat the passenger compartment of a battery-powered electric car (a Renault ZOE R240). The practical use of the heating system is analyzed in several test drives, performed during winter 2018. The results as well as the range extension of the electric car that can be achieved by substituting the on-board heating system by the fuel-operated heater are quantified herein.

Role of Artificial Intelligence (AI) in Surgery: Introduction, General Principles, and Potential Applications

2020 ◽  
Author(s):  
Alberto Mangano ◽  
Valentina Valle ◽  
Nicolas Dreifuss ◽  
Gabriela Aguiluz ◽  
Mario Masrur
Keyword(s):  
Artificial Intelligence ◽  
Cognitive Tasks ◽  
Future Perspectives ◽  
General Introduction ◽  
Computing Power ◽  
Interdisciplinary Field ◽  
Potential Applications ◽  
Number Of Publications ◽  
Surgical Setting

AI (Artificial intelligence) is an interdisciplinary field aimed at the development of algorithms to endow machines with the capability of executing cognitive tasks. The number of publications regarding AI and surgery has increased dramatically over the last two decades. This phenomenon can partly be explained by the exponential growth in computing power available to the largest AI training runs. AI can be classified into different sub-domains with extensive potential clinical applications in the surgical setting. AI will increasingly become a major component of clinical practice in surgery. The aim of the present Narrative Review is to give a general introduction and summarized overview of AI, as well as to present additional remarks on potential surgical applications and future perspectives in surgery.

scholarly journals Inheritance of seed size by hybrid populations of pea (F1, F2)

2020 ◽  
Vol 17 ◽  
pp. 00090
Author(s):  
Firzinat Davletov ◽  
Karina Gainullina ◽  
Fidan Safin
Keyword(s):  
Seed Size ◽  
High Efficiency ◽  
Research Work ◽  
Kernel Weight ◽  
Intraspecific Hybridization ◽  
Filial Generation ◽  
Economically Valuable Traits ◽  
Reciprocal Crossing ◽  
Selection Of ◽  
Parental Cultivar

Pea (Pisum sativum L.) is one of the ancient and valuable high-protein leguminous cultures in the world. Breeding of new high-yielding cultivars is the main reserve to increase production of pea seeds. At the present time, intraspecific hybridization has a great importance in selection of new cultivars of pea. However, consistent patterns of inheritance of a number of economically valuable traits by hybrids are still insufficiently investigated. The objective of this research work was to study inheritance of seed size (1000-kernel weight) by pea hybrids of the first and second filial generations (F1, F2). The crossing and back-crossing (reciprocal crossing) were conducted. In our experiments, the first filial generation hybrids (F1) had a lower 1000-kernel weight than the large-seeded parental cultivars. Herewith the large-seeded genotype of the female parental cultivar had more influence on displaying of this trait in hybrids than of the male parental cultivar. In the second filial generation hybrids (F2) showed intermediate inheritance of seed size. The results of our experiments attest high efficiency of seed size selection in segregating generations of hybrids, obtained from crosses between cultivars carrying genes of seed size.

Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injector: Part 14—Cooling Characteristics of the Particulate Core Material Debris Accumulated in Horizontal Narrow Gap

2006 ◽  
Author(s):  
Y. Hirao ◽  
G. Su ◽  
K. Sugiyama ◽  
T. Narabayashi ◽  
M. Mori ◽  
...  
Keyword(s):  
Heat Supply ◽  
Nuclear Power ◽  
High Efficiency ◽  
Hot Spot ◽  
Research Work ◽  
Lower Surface ◽  
Injection System ◽  
Core Material ◽  
Metal Debris ◽  
The Core

When LOCA occurs in proposed nuclear reactor systems, the coolability of the core would be kept by the SI core injection system and therefore the probability of the core meltdown is negligible small. In this research work, we make it clear that the coolability of the RPV bottom is secured even if a part of the core should melt and a substantial amount of debris should be deposited on the lower plenum. In this report, we examined experimentally the coolability of the RPV bottom that a Zircaloy-based loose debris layer is deposited on. We set up a heat supply section made by SUS304 on the loose debris layer and measured the heat flux released into the loose debris bed and the temperature at the lower surface of the heat supply section. In addition, we measured the temperature distribution at the bottom of the loose debris bed. It became clear in this study that the coolability depends on the amount of coolant supplied, and the hot spot would not occur when coolant is supplied. Even if a hotspot should occur in the oxidization of loose metal debris accompanied with rapid heat generation. It is found that when a small amount of coolant can be supplied, it disappears because of a high capillary force of oxidized loose debris. So it is confirmed that the soundness of RPV is basically maintained.

Research on Electric Linear Compressor for New Energy Vehicles

2011 ◽  
Vol 383-390 ◽  
pp. 5470-5473
Author(s):  
Yan Shi ◽  
Zong Li Li
Keyword(s):  
High Efficiency ◽  
Research Work ◽  
Structure Design ◽  
Low Friction ◽  
Compact Structure ◽  
Linear Compressor ◽  
New Energy ◽  
Air Brake System ◽  
Near Future ◽  
New Energy Vehicles

New energy vehicles have bright prospect in the near future. In new energy vehicles some parts which are driven by engine through transmission will be replaced by electric drive, such as refrigeration compressor used for air conditioning and air compressor used for air brake system. Because of advantages, such as high efficiency, low friction, compact structure, and so on, linear compressor is suitable to solve above problems. In this paper a novel electric linear compressor is presented. Research work, such as simulation, structure design, control design, has been done. Further experiments are being done by my research team. We believe that electric linear compressor is worthy of being researched to popularize new energy vehicles.

3D FE-Based Modelling and Simulation of the Micro Milling Process

2012 ◽  
Vol 516 ◽  
pp. 634-639 ◽  
Author(s):  
Tao Wu ◽  
Kai Cheng
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
Reasonable Agreement ◽  
Large Deformations ◽  
Helix Angle ◽  
Milling Process ◽  
Modelling And Simulation ◽  
Micro Milling ◽  
3D Finite Element ◽  
Milling Performance

Modelling and simulation of the micro milling process has the potential to improve tool design and optimize cutting conditions. This paper presents a novel and effective 3D finite element (FE) based method for simulating the micro milling process under large deformations. A tooling model incorporating a helix angle is developed for cutting forces, tooling temperature and chip formation prediction. The proposed approach is experimentally validated and the simulated micro milling performance such as micro chip formation and cutting forces are in reasonable agreement with the measured results in cutting trials.

Microstructural insights into the compressive failure of snow based on a peridynamic framework

2020 ◽  
Author(s):  
Jonas Ritter ◽  
Henning Löwe ◽  
Michael Zaiser
Keyword(s):  
Computed Tomography ◽  
Failure Modes ◽  
Large Deformations ◽  
Failure Mechanisms ◽  
Elastic Response ◽  
Problem Solution ◽  
Compaction Bands ◽  
Modes Of Failure ◽  
Computed Tomography Images ◽  
Non Local

&lt;p&gt;Highly-porous cohesive granular materials such as snow possess complex modes of failure. Apart from classical failure modes, they show microstructural failure and fragmentation associated with densification within a local, narrow zone. Therefore cracks may form and propagate even under compressive load (&amp;#8216;anticracks&amp;#8217;,&amp;#8217;compaction bands&amp;#8217;). Such failure modes are of importance in a range of geophysical contexts. For instance, they may control the release of snow slab avalanches and influence fracturing of porous rock formations. In the snow context, specific failure mechanisms of the ice matrix and their interplay with the microstructure geometry of snow are still poorly understood. Recently, X-ray computed tomography images have provided insights into snow microstructure and capability of directly simulating its elastic response by the finite element method (FEM). However, apart from thermodynamically driven healing processes the inelastic post-peak behaviour of the microstructure is controlled by localized damage, large deformations and internal contacts. As a result of the well-known limitations of FEM to capture these processes we use Peridynamics (PD) as a non-local continuum method to approach the problem. Due to its formulation, (micro)cracks and damage are emergent features of the problem solution that do not need to be known or located in advance. Furthermore, the Lagrangian character of the governing equations makes the method suitable for simulating large deformations. In this contribution we perform confined uniaxial compression simulations of snow microstructures within a peridynamic framework. Computed tomography images of snow specimen serve as a simulation data base. The obtained results show a novel insight into local failure of snow and allow a better comprehension of the underlying failure mechanisms. This study contributes to improve non-local macroscopic constitutive models for snow for future applications.&lt;/p&gt;

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