scholarly journals КАРКАСНА МОДЕЛЬ РОЗТЯГУВАННЯ КУЛІРНОГО ТРИКОТАЖУ ВЗДОВЖ ПЕТЕЛЬНИХ РЯДІВ

2022 ◽  
pp. 60-69
Author(s):  
SVITLANA BOBROVA ◽  
TETIANA YELINA ◽  
LIUDMYLA HALAVSKA ◽  
VOLODYMYR SHCHERBAN ◽  
OKSANA KOLISKO

Purpose. The purpose of this study is to develop a mathematical description of the transformation of the frame model of weft-knits under the action of tensile forces in the courswise direction for further three-dimensional modeling of the knited structure.Methodology. Methods of theoretical analysis and synthesis, basics of knitting theory, methods of geometric modeling and parameterization were used in the research process.Findings. Considering the knitwear stretching during the use of the clothing is one of the determining factors of the quality of design decisions. When stretching the weft-knitted fabrics in the coursewise direction, the configuration of its individual stitches’ changes, as well as the thread’s cross-section due to the force interaction between the adjacent structure elements. To simulate the physical and mechanical behavior of knitwear under the stretching, it is suggested using a complex model of knitwear deformation, that includes the suggested frame model of uniaxial coursewise stretching of knitted fabrics. An algorithm for constructing a frame model of stretching a sample of knitted fabric in the coursewise direction is described in the paper. The algorithm is based on the structure parameters, including the wale spacing and course spacing in a dry relaxed state, the relative elongation of the sample at the time of modeling, number of wales and courses in the sample, the coefficient of courses narrowing. Scientific novelty. The paper investigates the features of the transformation of the knitting structure during stretching in the coursewise direction and offers algorithmic and mathematical support for the automated generation of the mesh frame in the context of three-dimensional modeling, which provides for the possibility of considering the dynamics of deformation of knitted fabric undergoing tensile deformations.Practical value. Frame model of the weft-knits deformation and algorithm of mesh-frame construction suggested in the paper, form the basis for determination of coordinates of characteristic points of the structural elements of the knit in a state of uniaxial tension for construction of a three-dimensional model of thread a deformed knitted fabric.

2012 ◽  
Vol 546-547 ◽  
pp. 680-685
Author(s):  
Jie Fang ◽  
Xiao Feng Wang

OpenGL is independent of the window system, and did not provide the function to draw complex three-dimensional model, so it is difficult to properly control OpenGL and create complex model .This paper will achieve to build complex three-dimensional model efficiently and take good effect in practice with combining OpenGL and 3Dmax or with the help of functions of VC++ to develop based on applying window frame of Windows powerfully.


Author(s):  
Т. В. Єліна ◽  
Л. Є. Галавська ◽  
В. Ю. Щербань ◽  
О. З. Колиско ◽  
С. Ю. Боброва

The purpose of this study is to develop a frame model for stretching the weft-knits in the wale direction, suitable for further integration into the algorithm for building a three-dimensional knitwear model in a stretched state and modeling of interactive deformation dynamics. Methodology.  Methods  of  theoretical  analysis,  basics  of  knitting  theory,  topological  model  of knitwear, methods of geometric modeling and parameterization were used in the research process. Findings. Modeling the physical and mechanical behavior of knitwear in a computer environment is one of the promising ways to increase the level of conformity of knitted products with the requirements of comfort and functionality. However, the complexity of the internal structure, the anisotropy of properties and the instability of the parameters of the loop structure determine the need to find non-trivial ways to solve the problem of mathematical description of the three-dimensional model of the thread, knitted in the knitwear, considering the stretching deformations. During  the  study,  a  frame  model  of  a  uniaxial  stretching  of  knitwear  in  the  wale  direction  was developed. The basis of the frame model is the idea of a knitted structure, represented as a logically organized set of elements, each of which is interlaces with other elements in accordance with the topology of knit. The frame of the jersey fragment is described as a set of bars and hinges. The hinges are located at the interlacing points of the loop heads and loop feet, and each rod in the model is an imaginary element representing a complex of force factors that prevent the change of distance between the hinges connected to the given rod. In the process of stretching, the geometrical characteristics of the elements change, while the logical connections remain unchanged. The wireframe model allows to define coordinates of interlacement points in the coordinate system of the sample, relative position of coordinate systems of each elementary fragment, which correspond to  given  loops,  coordinates  of  characteristic  points  of  a loop  for  transition  to  a three-dimensional model of a knitted structure. Scientific novelty. For the first time, a frame model of deformation of the knit, suitable for three-dimensional modeling of its structure, considering deformation of the thrust, was developed. Practical value. The developed model can be used as mathematical support of systems of automated designing of knits.


2021 ◽  
Vol 20 (7) ◽  
pp. 48-61
Author(s):  
Pavel V. Chistyakov ◽  
Ekaterina N. Bocharova ◽  
Ksenia A. Kolobova

This article provides a detailed account of the process of scanning, post-processing and further manipulation of three-dimensional models obtained with structured light scanners. Purpose. The purpose of the study is determined by the need for national archaeologists to learn the methods of three-dimensional modeling for the implementation of scientific research corresponding to international standards. Unfortunately, this direction in national archaeology began to develop in a relatively recent time and there is a lag in the application of three-dimensional modeling of national archaeology compared to the world level. Results. Any archaeological, experimental or ethnographic artifact can be used for three-dimensional scanning. To perform post-processing of three-dimensional models it is necessary to carry out primary scanning of an artifact by one of the existing algorithms. The algorithm for creating models, their positioning, simplification, saving in various formats and export is described. The main sequence of 3D models post-processing includes: processing of groups of scanned projections (their cleaning and alignment), creation of artifact model and processing/rectification of the resulting model using special software. Conclusion. As a result of correct implementation of the algorithm, the researcher receives a scaled model completely corresponding to the original artifact. Obtaining a scalable, texture-free three-dimensional model of the artifact, which fully corresponds to the original and exceeds a photograph in the quality of detail transfer, allows a scientist to conduct precise metric measurements and any procedures of non-invasive manipulation of the models. The ability to access a database of three-dimensional models of archaeological collections greatly simplifies the work of archaeologists, especially in situations when country borders are closed.


2014 ◽  
Vol 644-650 ◽  
pp. 2674-2677
Author(s):  
Kun Wang ◽  
Ke Yan Xiao

In order to study the evolution and metallogenic regularity of MVT lead-zinc deposits in western portion of Hunan province (China), two sets of three-dimensional model are established by Minexplorer software: 3D model in typical deposit and 3Dmodel on regional scale. On the basis of synthetic analyses of two sets of models, the further prospecting should be focused on the north part of ore-bearing layer along the Huayuan-Zhangjiajie fault belt. It is effective to observe occurrence and distribution characteristics from the 3D geological model, and to provide the basis for further exploration prospecting of the concealed deposits.


2011 ◽  
Vol 271-273 ◽  
pp. 211-215
Author(s):  
Ming Ming Ji ◽  
Lin Hua Piao ◽  
Bai Hua Li

Using ANSYS program, the finite element simulation based on thermoelectric coupling is conducted by a series of procedures, such as three-dimensional model building of airflow level posture sensor according to the actual size of the proportion, network modifying, loads applying and equation solving. The sensitive mechanism of airflow level posture sensor is explained by finite element method. The numerical results show that compared with two-dimensional modeling, the simulation result of three-dimensional modeling and thermoelectric analysis methods are more comprehensive and accurate, which provides more reliable basis for practical research of the airflow level posture sensor.


2018 ◽  
Vol 7 (1) ◽  
pp. 45
Author(s):  
Zhanghao Ren

In the process of engineering and geological surveys, three-dimensional engineering-geological modeling makes it possible to perform a comprehensive assessment of the state of the territory for making sound-design decisions on the placement of construction sites and their structures. Secondly, a logical conclusion of a detailed study of engineering-geological and geotechnical conditions, which is implemented to use three-dimensional modeling, is a well-grounded design with a reasonable margin of safety, which causes a reduction in the total cost of the erected or reconstructed structure. Thirdly, in comparison with traditional engineering-geological two-dimensional models (cuts, maps, etc.), three-dimensional models give more information. This is especially important, when we think about the scale of the hydraulic structures. According to archival materials, it can be noted that there are many spatial geological heterogeneities in this territory, and the engineering-geological conditions turned out to be complex. Taking into account the advantages of three-dimensional modeling, the creation of a three-dimensional model of a dispersed soil massif is an actual task for solving complex engineering-geological problems. The article analyzes a three-dimensional engineering-geological model of the soil massif under a hydrotechnical building in the Moscow region, and then calculates its stress-strain state and the coefficient of stability of the sides of the ditch.


2019 ◽  
Vol 7 ◽  
pp. 62-66
Author(s):  
Alexandra Zhuravleva

This article demonstrates the possibility of a graphical program Kompas ASCON in the sphere of three-dimensional modeling of engineering and building objects. The created three-dimensional model of the training class for employees of JSC "Russian Railways" to study safety rules can have a real embodiment – all components are built according to catalogs and statements. In the course of work on this project various tools of the program are mastered: models of the room of a class of furniture are created. The basic operations of three-dimensional modeling and methods of creating assembly units are studied. All components of the class are paired. The resulting project has a high visibility and can be used as a presentation as a company that performs class projects, and the customer.


2020 ◽  
Vol 10 (5) ◽  
pp. 1857 ◽  
Author(s):  
José Ignacio Rojas-Sola ◽  
Eduardo De la Morena-De la Fuente

This article shows the geometric modeling and virtual reconstruction of the optical telegraph by Agustín de Betancourt and Abraham Louis Breguet developed at the end of the 18th century. Autodesk Inventor Professional software has been used to obtain the three-dimensional (3D) model of this historical invention and its geometric documentation. The material for the research is available on the website of the Betancourt Project of the Canary Orotava Foundation for the History of Science. Thanks to the three-dimensional modeling performed, it has been possible to explain in detail both its operation and the assembly system of this invention in a coherent way. After carrying out its 3D modeling and functional analysis, it was discovered that the transmissions in the telegraph were not performed by hemp ropes but rather by metal chains with flat links, considerably reducing possible error. Similarly, it has also been found that the use of the gimbal joint facilitated the adaptability of the invention to geographical areas where there was a physical impediment to the alignment of telegraph stations. In addition, it was not now necessary for the telescope frames to be located parallel to the mast frame (frame of the indicator arrow) and therefore they could work in different planes.


2019 ◽  
Author(s):  
Alexander Bashkatov

The tutorial is an introductory course to the study of the basics of geometric modeling for 3D printing using the programming language OpenSCAD and is built on the basis of descriptions of instructions for creating primitives, determining their properties, carrying out transformations and other service operations. It contains a large number of examples with detailed comments and description of the performed actions, which allows you to get basic skills in creating three-dimensional and flat models, exporting and importing graphical data. Meets the requirements of the Federal state educational standards of higher education of the last generation. It can be useful for computer science teachers, students, students and anyone who is interested in three-dimensional modeling and preparation of products for 3D printing.


2013 ◽  
Vol 385-386 ◽  
pp. 1780-1784
Author(s):  
Li Jun Xue ◽  
Li Li Wang

Virtual reality scenes three-dimensional modeling usually is constructed on the basis of learning with virtual data, and learning behavior is too dependent on virtual data.It is difficult to quickly and accurately reflect characteristics of 3D modeling in virtual reality, and learning complexity is higher. In this paper, a method of virtual reality scenes three-dimensional modeling based on semantic was presented on the basis of analysis of the virtual scenes modeling methods. The modeling system architecture using the method is divided into physical model libraries, three-dimensional model semantic knowledge base, semantic-based visual modeling and scene graph automatically generation modules. The experimental results show that the detection performance is better than the results of the three-dimensional modeling based on virtual data, and the system increases flexibility and usability of the three-dimensional modeling,


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