Wyniki wyszukiwania - BazTech

1

Numerical Analysis of Large Deflections of a Flat Textile Structure with Variable Bending Rigidity and Verification of Results Using Fem Simulation

Szablewski Piotr

Autex Research Journal

|

2021

|

Vol. 21, no. 1

108--114

EN

The paper presents the numerical modeling of large deflections of a flat textile structure subjected to a constant force acting on the free end. It was assumed that the examined structure is inextensible. The effect of the structure's own weight was also taken into account. In order to solve the problem, the flat textile structure was modeled using the heavy elastica theory. An important element of the analysis involves taking into account the variable bending rigidity of the examined textile structure along its length, which is often found in this type of products. The function of variable bending rigidity was assumed in advance. Numerical calculations were carried out in the Mathematica environment using the shooting method for the boundary value problem. The obtained results were verified using the finite element method.

2

Wpływ struktury tkaniny na jej przepuszczalność promieniowania UV

Dulęba-Majek M.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

|

2006

|

z. 62

27-41

PL

Praca dotyczy badań określających możliwości projektowania przestrzeni międzynitkowych w tkaninie, odpowiedzialnych za przepuszczalność promieniowania ultrafioletowego. Przedmiotem badań były przestrzenne konfiguracje dwóch par nitek osnowy i wątku, zwane modułami strukturalnymi.

EN

The work concerns the research qualifying the possibilites of designing the inter-threads spaces in the fabric, responsible for the transmission of the UV radiation. The subject of the research were the spatial configurations of two pairs warp and weft threads described as structural modules.

3

Nowoczesne metody oceny zmian w strukturach wyrobów włókienniczych powstających w wyniku działania sił

Witkowska B., Kamińska I.

Prace Instytutu Włókiennictwa

|

2006

|

R. 56

59-67

PL

W artykule zaprezentowano niestandardowe metody badań i oceny tekstyliów prowadzone z wykorzystaniem maszyny wytrzymałościowej. Metody te umożliwiają pomiary i ocenę zmian zachodzących w strukturze wybranych asortymentów tekstyliów pod wpływem działania sił, a także przy zastosowaniu dodatkowych elementów jak np. kamera cyfrowa, wizualizację tych zmian. Poniżej opisano metody badawcze dotyczące oceny właściwości sprężystych dzianin dystansowych i tkanin elastycznych oraz metodę umożliwiającą rejestrację przebiegu zmian zachodzących w tkaninach podczas statycznego rozdzierania.

EN

Continuous development of new structures of textile products, a need for extensive knowledge of the phenomena that take place in the structure of these products, and also the application of modern techniques in analysis of these changes, make new requirements for research laboratories. They concern improvement of research methodology and implementation of methods that have not been used so far in laboratory tests. Every textile product during a so called "life cycle" is subjected to multidirectional forces which cause deformations and changes in its structure. These changes are often studied using tension testers CRE (constant rate of specimen extension). Irrespective of their sophistication (either computer-aided or not) these machines can be used to analyze extension, compression and cyclic extension and compression of textile products. For typical structures such as fibers, threads, flat textile products, 3D products, e.g. cellular plastics, the above tests are made most often using standard research methods. Appearance of new 3D structures of textile products such as warp-knitted spacer structures or shaped products requires adjustmen of the tension tester instrumentation and development of new research methods that enable estimation of physico-mechanical properties of these products. In the Institute of The Textile Materials Engineering in Lodz, such methods were developed to determine the resistance to flattening, elasticity during cyclic compression and elasticity under the stress for warp-knitted spacer structures. Another problem is the use of visualization and image analysis techniques to record and estimate destructive tests made using the CRE machine. In our Institute a computer image analysis system was designed and constructed to guarantee continuous recording of changes that take place in the textile structures. This system enabled observation and separation of a so-called tear zone in textiles which contributed to estimation of the zone geometry. Basing on experimental investigations, methods for measurement of the tear zone geometry were developed. An advantage of the computer image analysis system is its multi-functionality. It can be used also to reconstruct and measure changes in textile structures during other tests, e.g. when combustibility or wetting is tested. The program for image analysis facilitates also documentation and presentation of results. The above unconventional research methods developed in the Institute of The Textile Materials Engineering with the use of the CRE machine will be discussed in the paper.