Abstraction of Semantic Mid-Surface Based on Rib-Feature Recognition

Author(s):  
Huawei Zhu ◽  
Yusheng Liu

Mid-surface abstraction is an effective simplification method for thin-wall models. The complexity of finite element analysis (FEA) for a mid-surface model can be reduced greatly after abstraction. Although the model decomposition method is adopted for mid-surface extraction, it is hard to obtain the correct mid-surface model for complex models since the existing heuristic rule based methods lack of design intention. In addition, the mid-surface model is not easy to reuse. In this study, a semantic based mid-surface model representation and generation method is proposed. Firstly, a hierarchical semantic mid-surface model based on rib-feature decomposition is proposed. Secondly, based on the reorganization of rib-features and decomposition of the thin-wall model, the rib-features’ semantic information are obtained by the abstraction of the structure and connection in the thin-wall model. Then the hierarchical structure is generated by connection semantics. According to the various structure semantics, different abstraction methods will be employed to get the mid-surface patch for each sub region. Finally, the hierarchical semantic mid-surface model is constructed by the generation of the connection relationship between mid-surface patches based on the connection semantics between the rib-features. This semantic model ensures the high efficiency and accuracy of mid-surface regeneration when local modifications occur to a thin-wall model. A typical example is given to demonstrate the process.

2013 ◽  
Vol 41 (1) ◽  
pp. 60-79 ◽  
Author(s):  
Wei Yintao ◽  
Luo Yiwen ◽  
Miao Yiming ◽  
Chai Delong ◽  
Feng Xijin

ABSTRACT: This article focuses on steel cord deformation and force investigation within heavy-duty radial tires. Typical bending deformation and tension force distributions of steel reinforcement within a truck bus radial (TBR) tire have been obtained, and they provide useful input for the local scale modeling of the steel cord. The three-dimensional carpet plots of the cord force distribution within a TBR tire are presented. The carcass-bending curvature is derived from the deformation of the carcass center line. A high-efficiency modeling approach for layered multistrand cord structures has been developed that uses cord design variables such as lay angle, lay length, and radius of the strand center line as input. Several types of steel cord have been modeled using the developed method as an example. The pure tension for two cords and the combined tension bending under various loading conditions relevant to tire deformation have been simulated by a finite element analysis (FEA). Good agreement has been found between experimental and FEA-determined tension force-displacement curves, and the characteristic structural and plastic deformation phases have been revealed by the FE simulation. Furthermore, some interesting local stress and deformation patterns under combined tension and bending are found that have not been previously reported. In addition, an experimental cord force measurement approach is included in this article.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4407
Author(s):  
Mbika Muteba

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.


2008 ◽  
Vol 575-578 ◽  
pp. 174-179
Author(s):  
Juan Hua Su ◽  
Feng Zhang Ren ◽  
Lei Wang

This paper analyzes the forming process methods of fin used in CPU chip to emit heat. The whole process is blanking, the first forging forming, the second forging (sizing), and trimming. The chamfer design of CPU fin blank is simulated by finite element analysis. The optimized chamfer 1.6 mm is available. Semi-enclosed cold forging of progressive dies is put forward. The newly designed transfer unit is applied, which unifies the merit of high efficiency of the progressive dies and the high material-using ratio of the project die. Quick disassembly structure is designed and pins are used as quick disassembly pins by means of ball bearing bushing. The unique processing of the shearing scrap structure is adopted when designing the inverted trimming dies. Compared with the traditional die, the mechanization and electrization are realized to increase the production efficiency and get highly precise CPU fin.


Author(s):  
Jiaman Hong ◽  
Bo Wang ◽  
Xiaoqing Zhu ◽  
Zhichao Xiong ◽  
Yusen Huang ◽  
...  

In this paper, a novel embedded reflective grating (ERG) is presented to realize bi-function polarization operating at infrared band by finite element analysis (FEM). For transverse electric (TE) polarization, a two-port output (0th and −2nd orders) with an efficiency of more than 47% and excellent uniformity can be obtained. For transverse magnetic (TM) polarization, a high efficiency output of 94.72% can be achieved at the −2th order. The results of the analysis of the electric field intensity distribution, angular and wavelength bandwidths further demonstrate the advantages of the proposed grating. In addition, the tolerance analysis of period and duty cycle prove the feasibility of the grating in practical production.


2021 ◽  
pp. 1-30
Author(s):  
Weijun Shen ◽  
Yang Cao ◽  
Xuepeng Jiang ◽  
Zhan Zhang ◽  
Gül E. Okudan Kremer ◽  
...  

Abstract Origami structures, which were inspired by traditional paper folding arts, have been applied for engineering problems for the last two decades. Origami-based thin-wall tubes have been extensively investigated under axial loadings. However, less has been done with radial stiffness as one of the critical mechanical properties of a tubular structure working under lateral loadings. In this study, the radial stiffness of novel thin-wall tubular structures based on origami patterns have been studied with compression tests and finite element analysis (FEA) simulations. The results show that the radial stiffness of an origami-inspired tube can achieve about 27.1 times that of a circular tube with the same circumcircle diameter (100 mm), height (60 mm), and wall-thickness (2 mm). Yoshimura, Kresling, and modified Yoshimura patterns are selected as the basic frames, upon which the influences of different design parameters are tested and discussed. Given that the weight can vary due to different designs, the stiffness-to-weight ratio is also calculated. The origami-inspired tubular structures with superior stiffness performances are obtained and can be extended to crashworthy structures, functional structures, and stiffness enhancement with low structural weight.


2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Jie Sun ◽  
Ke Chen

Nucleotides play a central role in life-form metabolism, by interacting with proteins and mediating the function of proteins. It is estimated that nucleotides constitute about 15% of the biologically relevant ligands included in PDB. Prediction of binding sites of nucleotides is useful in understanding the function of proteins and can facilitate the in silico design of drugs. In this study, we propose a nucleotide-binding site predictor, namely, NSiteMatch. The NSiteMatch algorithm integrates three different strategies: geometrical analysis, energy calculation, and template comparison. Unlike a traditional template-based predictor, which identifies global similarity between target structure and template, NSiteMatch concerns the local similarity between a surface patch of the target protein and the binding sites of template. To this end, NSiteMatch identifies more templates than traditional template-based predictors. The NSiteMatch predictor is compared with three representative methods, Findsite, Q-SiteFinder, and MetaPocket. An extensive evaluation demonstrates that NSiteMatch achieves higher success rates than Findsite, Q-SiteFinder, and MetaPocket, in prediction of binding sites of ATP, ADP, and AMP.


2021 ◽  
Author(s):  
Kuros Yalpani

An algorithm is proposed that extracts 3D shape from shading information in a digital image. The algorithm assumes that there is only a single source of light producing the image, that the surface of the shape giving rise to the image is Lambertian (matte) and that its shape can be locally approximated by a quadratic function. Previous work shows that under these assumptions, robust shape from shading is possible, though slow for large images because a non-linear optimization method is applied in order to estimate local quadratic surface patches from image intensities. The work presented here shows that local quadratic surface patch estimates can be computed, without prior knowledge of the light source direction, via a linear least squares optimization, thus greatly improving the algebraic complexity and run-time of this existing algorithms.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xiujin Yu ◽  
Shengfu Liu ◽  
Hui Zhang

As one of the oldest languages in the world, Chinese has a long cultural history and unique language charm. The multilayer self-organizing neural network and data mining techniques have been widely used and can achieve high-precision prediction in different fields. However, they are hardly applied to Chinese language feature analysis. In order to accurately analyze the characteristics of Chinese language, this paper uses the multilayer self-organizing neural network and the corresponding data mining technology for feature recognition and then compared it with other different types of neural network algorithms. The results show that the multilayer self-organizing neural network can make the accuracy, recall, and F1 score of feature recognition reach 68.69%, 80.21%, and 70.19%, respectively, when there are many samples. Under the influence of strong noise, it keeps high efficiency of feature analysis. This shows that the multilayer self-organizing neural network has superior performance and can provide strong support for Chinese language feature analysis.


Author(s):  
K R Parker

Particulate control equipment for the larger industrial processes, which can effectively collect particles in the submicrometre range, is limited to the electrostatic precipitator and bag filter as cost effective methods. To meet ever decreasing emission levels, demanded by the Regulatory Agencies, the equipment suppliers and academics are involved in ongoing research and development activities in order to obtain a better understanding of the collection process itself, such as to achieve improved performance and, equally importantly, plant reliability and availability. This paper reviews some of the activities in the electrical, microelectronics, material sciences, fluid flow and finite element analysis fields and indicates how the findings are leading to new designs that are more reliable and also how the improvements are making the equipment more cost effective while operating at a higher performance level. Finally, with the concern over the emission of ‘air toxics’, while both the electrostatic precipitator and bag filter are established technology for effectively removing solid and liquid particulates with sizings well below 1 micrometre there is now an additional requirement for collecting vapour phase materials to meet the latest regulatory emission levels. Some ideas and approaches are examined which can prove effective in collecting the majority of materials classified as ‘air toxics’, such that the equipment will meet the existing and possible future emission standards.


Temperature is not only an important parameter in machining, but also an important basis for process optimization. Accurate prediction and reasonable analysis of grinding temperature is of great and far-reaching significance to the development and promotion of nanofluid micro-lubrication. In this chapter, the mathematical model of finite element simulation of temperature field of high efficiency deep grinding under four kinds of cooling lubrication conditions is established, and the three boundary conditions and the constraints of simulation model are established, and the mesh division and time step algorithm are determined respectively. Using ABAQUS simulation platform and theoretical model to simulate grinding temperature field, the distribution characteristics of grinding temperature field under different working conditions are analyzed from different directions, different grinding depths, and different workpiece materials.


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