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3D Simulation of Warp Knitted Structures with a New Algorithm Based on NURBS

Xu H Y, Chen N L, Jiang J H, Jin L X, Wang Z X

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 1 (109)

57--60

EN

In order to obtain a three-dimensional computer simulation of warp knitted structures with more flexibility and realism, a new algorithm using Matlab was developed by NURBS based on empirical geometrical loop models. With the principles of NURBS curves, once the values of data points are known, the control points with two coincidence points at the start and end points can be uncomplicatedly calculated by Matlab. Then the NURBS curve of a single typical stitch can be simulated flexibly by Matlab. A new typical stitch selected from two stitches simulated directly by the new method is redefined to improve the joint of neighboring stitches, and it is found that there are two types of redefined typical warp knitted stitches judged by whether the two under lap on the same side or not. Based on the redefined typical warp knitted stitch, two warp knitted structures are simulated regardless of the loop offset, and all the joints of stitches are smooth.

PL

Przeprowadzono symulację komputerową struktur dzianin w wymiarze 3D, opracowując w tym celu nową procedurę opartą na algorytmie NURBS. Do tego celu wykorzystano oprogramowanie MATLAB. Symulację 3D przeprowadzono w oparciu o procedury numeryczne umożliwiające wykreślenie przestrzennych figur geometrycznych opisujących strukturę dzianin. Symulowano kształt oczek zamkniętych i otwartych podstawowych splotów kolumienkowych trykotu, sukna i aksamitu. W oparciu o 8 punktów referencyjnych zorientowano konfigurację pętli oczka i łącznika w postaci przestrzennej linii eliptycznej. Do zapisu struktury splotu kształtu oczek wykorzystywano aparat matematyczny w postaci macierzy.

2

Computer based real time systems for analyzing cardiovascular response to orthostatic stress

Khan M., Vashisth S., Vijay R., Salhan A. K.

Biocybernetics and Biomedical Engineering

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2015

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Vol. 35, no. 4

232--239

EN

The cardiovascular response to orthostatic (gravitational) stress has been the focus of several researches in the past. Average values of hemodynamic variables, such as arterial pressure or heart rate are recorded during changes in posture for diagnosing orthostatic stress clinically. Different methods based on varied physical principles have been developed to measure these hemodynamic variables. Carotid artery is responsible for direction of blood flow to brain and provides a vital physiological parameter which can be used to construe cardiac information. A noninvasive system has been built in which a piezoelectric sensor is positioned on the carotid artery of the subject and carotid signals of fifteen human subjects are acquired in various body postures using application softwares. RR intervals and pulse amplitudes are computed after filtering and analyzing the carotid signal recordings using these softwares. The developed system is validated by determining the percentage change in RR interval and pulse amplitude of all the subjects which is found almost same. The technique used in the proposed system may be applied to measure and manage the orthostatic stress.

3

Laboratorium Eksperymentów Fizycznych

Spustek H.

Logistyka

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2014

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nr 6

9912--9917

PL

W artykule poruszono problem modelowania zjawisk fizycznych przy użyciu oprogramowania Matlab – Simulink firmy The MathWorks, Inc z siedzibą w USA. Pakiet Matlab – Simulink umożliwia modelowanie, symulację i analizę systemów o zmiennej dynamice. Simulink stanowi kompletne środowisko programistyczne przystosowane do modelowania i implementacji systemów dynamicznych. Otwarta architektura umożliwia wykonanie modelu i zintegrowanie go z innymi środowiskami. Przedmiotem zainteresowania autora jest implementacja komputerowa modelu ruchu jednostajnie przyspieszonego w odniesieniu do wybranego problemu mechaniki klasycznej. Pokazane tutaj zagadnienie wchodzi w zakres Laboratorium Eksperymentów Fizycznych (LEF) budowanego w ramach kierunku studiów inżynieria bezpieczeństwa w Wyższej Szkole Oficerskiej Wojsk Lądowych imienia generała Tadeusza Kościuszki we Wrocławiu.

EN

The paper addresses the issue of modeling of the physical phenomena by using the the software Matlab – Simulink of The MathWorks Inc. Matlab – Simulink to model, simulate and analyze systems with variable dynamics. Simulink provides a complete development environment for modeling and implementation of dynamic systems. Open architecture allows execution model and integrate it with other environments. The focus of the author is to implement a computer uniformly acceleration motion model for selected problem of the classical mechanics. The issue is the subject of exercises of the Laboratory of Physical Experiments (LPE) built under the direction of engineering safety studies at the General Tadeusz Kosciuszko Military Academy of Land Forces in Wroclaw.