Three-dimensional modeling and simulation of deformation behavior of fancy weft knitted stitch fabric

2016 ◽  
Vol 87 (14) ◽  
pp. 1742-1751 ◽  
Author(s):  
Sha Sha ◽  
Pibo Ma ◽  
Lisa Parrillo Chapman ◽  
Gaoming Jiang ◽  
Aijun Zhang

In order to obtain deformation behavior and volumetric characteristic of fancy weft knitted fabric, loop models are built on improved particle systems in this article. The problem of the non-uniform rational B-splines (NURBS) curves, which cannot pass through all control points, is solved by using an interpolation algorithm which can generate new auxiliary points. To simulate the twist of folded yarns, the NURBS curves are regarded as the geometric center, which is rotated with cylinders whose three relative Euler angles are calculated by the spatial coordinates of adjacent points. By analyzing the relationship between the deformation of the loop and the displacement of the particles, the deformation behavior of fancy weft knitted stitches is simulated. Velocity-Verlet, a numerical integration, is introduced to simulate fancy weft knitted stitches, and stable results are obtained. The results show that these models and algorithm accurately display the deformation behavior of fancy weft knitted stitches, as demonstrated by qualitative comparisons to measure the deformations of actual samples, and the simulator can scale up to animations with complex dynamic motion.

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3325
Author(s):  
Valery Ochkov ◽  
Inna Vasileva ◽  
Ekaterina Borovinskaya ◽  
Wladimir Reschetilowski

This paper considers an approach towards the building of new classes of symmetric closed curves with two or more focal points, which can be obtained by generalizing classical definitions of the ellipse, Cassini, and Cayley ovals. A universal numerical method for creating such curves in mathematical packages is introduced. Specific aspects of the provided numerical data in computer-aided design systems with B-splines for three-dimensional modeling are considered. The applicability of the method is demonstrated, as well as the possibility to provide high smoothness of the curvature profile at the specified accuracy of modeling.


2020 ◽  
Vol 21 (2) ◽  
pp. 105-112
Author(s):  
Dmitry G. Allenov ◽  
Kristina B. Deinova ◽  
Sergey V. Solomatin ◽  
Olga I. Lazarenko

The scientific work represents a research of the cutting process in order to determine the influence of the cutting tool extensions length from the tool holder and the cutting forces that occur during processing and corresponding to different values of the removed layer on the formation of the quality of the surface layer of parts during turning. As a cutting tool, the research used a PCLNR2525M12 straight-turning tool with replaceable T15K6 carbide inserts. Steel cylindrical workpieces with a diameter D = 40 mm (steel grade - 30) were used as workpieces. Cutting was carried out at three different cutting depths: 0.4, 1, 1.5 mm. The feed rate and spindle speed throughout the experiment were constant and were equal to s = 0.1 mm/rev, n = 1000 rpm, respectively. The geometric deviations of the cutter from the theoretical cutting line were determined by mathematical modeling methods. Linear displacements formed due to the stress-strain state of the cutter were used as estimated parameters. The study presents the methodology for preparing and conducting mathematical modeling using the three-dimensional modeling system KOMPAS-3D and APM FEM module. The roughness parameters that occur during turning by cutters with different tool extension with different cutting modes were studied experimentally.


2011 ◽  
Vol 56 (3) ◽  
pp. 766-770 ◽  
Author(s):  
Delphine Tardivo ◽  
Julien Sastre ◽  
Michel Ruquet ◽  
Lionel Thollon ◽  
Pascal Adalian ◽  
...  

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