Wyniki wyszukiwania - BazTech

1

Membranowe przekrycia dachowe Część 2 – detale konstrukcyjne

Pańtak M.

Builder

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2016

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R.20, nr 4

75--79

PL

Detale konstrukcyjne stanowią w zadaszeniu elementy kluczowe, niejednokrotnie decydujące o właściwej i bezpiecznej pracy oraz eksploatacji zadaszenia, jego trwałości i kosztach budowy.

EN

The article presents the design process of lightweight membrane roofs made of technical fabrics. Main emphasis in the second part of the article has been put on construction details usually being key in the design, as correct and safe work and use of the roof, as well as the cost and durability depends on them.

2

Economic Analysis of the Modern Textiles & Clothing Market within the Process of Final Completion of the ACT/WTO Agreement

Wysokińska Z.

Fibres & Textiles in Eastern Europe

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2009

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Vol. 17, no. 1 (72)

7--12

EN

The aim of the paper is to present main tendencies in global and European textile and clothing trade and competitive position of different regions and products especially Far East of Asia countries in the context of the liberalization process within the WTO. Dynamic development of constructions, generating needs for functional, comfortable and decorative designs, decorative clothes, textile wallpapers, carpets and textile floor coverings connected with equipment of interiors of companies, houses and flats (decorative textiles examined in the paper). Increasing importance of the quality of action of the specialized rescue service, which is connected with the increase of dangers resulting from higher freedom of movement of people and liberalization of labor market at an international scale – this results in increase of demand for highly specialized technical textiles also detailed examined in the paper.

PL

Celem artykułu jest prezentacja głównych tendencji w globalnym i europejskim handlu towarami tekstylnymi i odzieżowymi oraz pozycji konkurencyjnej różnych regionów i produktów, ze szczególnym uwzględnieniem azjatyckich krajów Dalekiego Wschodu w kontekście procesów liberalizacyjnych w ramach WTO. Dynamiczny rozwój budownictwa i rynku nieruchomości, generował w ostatnich latach wysokie zapotrzebowanie na funkcjonalne wzory i dekoracyjne tkaniny przeznaczone na wyposażenie biur i domów mieszkalnych jak również na tapety i dywany. Z kolei rozwój sektora usług publicznych świadczonych przez różnego rodzaju służby ratownicze, jak również służby ochronne, w związku ze zwiększoną, w dobie globalizacji, swobodą migracji osób w skali międzynarodowej, sprzyjał rozwojowi popytu na wysoko innowacyjne tkaniny techniczne przeznaczone do produkcji odzieży ochronnej. Zarówno tkaniny dekoracyjne jak i techniczne zostały poddane analizie w niniejszym artykule.

3

Rheological Properties of Technical Fabric

Komar W., Kłosowski P., Woźnica K.

Machine Dynamics Problems

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2008

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Vol. 32, No. 2

24-37

EN

This work presents a brief results comparison of two different attempts at the nonlinear characteristics of the same textile "Panama", manufactured by Sattler Company (Germany). On the basis of uniaxial tension and creep-recovery laboratory tests the rheological properties of technical fabric were identified. To describe material's nonlinear behaviour in its inelastic range constitutive relations of viscoplasticity and viscoelasticity were applied. The same procedure of the parameters identification, using the least squares method in the Levenberg-Marquardt variant, was conducted in each theory. Calculations were carried out for warp and weft threads individually, that is in two perpendicular directions of the material's weaving. Identification results were verified and compared to the experiments. Both nonlinear model representations advantageously approximate the tests' data of the examined technical fabric.

4

On Finite Element Modelling of Architectural Fabrics for Ganging Roofs

Ambroziak A., Kłosowski P., Woźnica K.

Machine Dynamics Problems

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2006

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Vol. 30, No. 2

7-17

EN

This paper deals with the constitutive modelling and identification of coated woven fabrics properties. The authors give brief characterization of the constitutive models used for the material modelling and discuss in details the fundamental equations of the dense net model. The special identification method of the non-linear elastic properties of the coated fabric is presented. The material parameters are determined on the base of uniaxial tensile tests in the warp and weft directions. For the identification process, techniques using the least squares method are applied. Additionally, the results of the uniaxial tension tests are compared with biaxial tension tests.

5

Identification of Nonlinear Viscoelastic Properties of the "Panama" Fabric

Komar W., Kłosowski P., Woźnica K.

Machine Dynamics Problems

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2006

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Vol. 30, No. 2

63-70

EN

Technical fabric "Panama", manufactured by Sattler Company (Germany), exhibits some nonlinear behaviour including the viscoelastic effects, during the long-term experiments. On the basis of uniaxial creep-recovery laboratory tests, conducted for five different stress levels from 10% to 50% of the ultimate force declared by the producer, an attempt on the nonlinear viscoelastic identification of the fabric properties was made. The Schapery one-integral model of nonlinear viscoelasticity was applied as the constitutive relation, describing material's behaviour in inelastic range. The power law time function was assumed to represent the transient component of the linear creep compliance. For each stress level the same procedure of the parameters identification was conducted, using the least squares method in the Levenberg-Marquardt variant. As the considered material has two thread families, warp and weft, weaved perpendicularly one to another, calculations were carried out for each thread direction individually. Results of the identification were verified and compared to the experiments' data. Good agreement between the nonlinear model representation and the tests' data of the examined technical fabric was obtained. Some remarks upon further research were included.

6

Charakterystyka tkaniny technicznej "Panama" w zakresie lepkosprężystym

Komar W.

Biuletyn Wojskowej Akademii Technicznej

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2006

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Vol. 55, nr 4

267-281

PL

Niniejszy artykuł zawiera część prac nad pełnym scharakteryzowaniem tkanin technicznych. Obiektem zainteresowania jest tkanina techniczna "Panama" firmy Sattler. Autor postawił sobie za cel zidentyfikowanie parametrów wybranych lepkosprężystych modeli konstytutywnych materiałów oraz ich weryfikację na podstawie prób jednoosiowego rozciągania ze stałą prędkością odkształcenia. Zaprezentowano dwa wybrane do identyfikacji modele lepkosprężyste, z których jeden jest reprezentowany liniowym równaniem różniczkowym, a drugi - nieliniową zależnością całkową. Dokonano zestawienia otrzymanych wyników z przeprowadzonej już części identyfikacji. Zaproponowano metodę ulepszającą proces identyfikacji parametrów modelu standardowego dla materiałów o charakterystykach nieliniowych. Przedstawiono aktualny stan prac nad identyfikacją kierunki dalszych badań.

EN

Technical fabrics are more often used in different industry interests. Mainly in the civil engineering structures like hanging roofs or pneumatic stores, but also as the road structures reinforcement or transporting belts. The subjected textile, considered in this paper is the technical fabric "Panama", manufactured by Sattler company (Germany). It has two identical polyester thread families: warp and weft of P2/2 weaving with double side PVC coating. Despite the anisotropy of that fabric, it has been assumed that its threads were made of the isotropic material. The research presented here is concerned with the identification of the "Panama" fabric behaviour, for each thread family separately, using the constitutive relations of linear and nonlinear viscoelasticity. The research is based on the laboratory tests of uniaxial tension with the constant strain rate. Tests were conducted for five different strain rate levels from 10⁻⁵ ; till 1.67×10⁻³ ; [1/s]. For linear representation of the examined material, the three-parameter model of viscoelastic solid was applied in a form of the differential equation, and the one-integral relation of the Schapery model was assumed to describe the nonlinear viscoelasticity of examined material. Models selected for further examination were presented more precisely. The identification process based on the linear standard model was conducted using the least squares method in the Marquardt-Levenberg variant. The calculated parameters were subsequently verified and the results were compared to the experiments. As it soon turned out, some problems with parameters determination occurred, and it was necessary to modify the linear viscoelastic model, to make it able to describe the "Panama" behaviour with reference to the tension tests. The proposed modification method was presented in the paper and improved results of material's description were compared to the experiments. Some negative aspects of the identification procedure were finally pointed out, and the next steps in the research schedule were suggested, to tend towards the main aim of this investigation, that is the entire viscoelastic characterization of the "Panama" fabric.

7

Analysis of the Mechanical Properties of Woven and Nonwoven Fabrics as an Integral Part of Compound Fabrics

Dubrovski P. D., Čebašek P. F.

Fibres & Textiles in Eastern Europe

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2005

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Vol. 13, no. 3 (51)

50--53

EN

In this paper the difference between the mechanical properties of woven and nonwoven fabrics is presented, and the important role of constructional parameters (particular the cover factor) of reinforcement fabric in the compound fabric is stressed. Some basic mechanical properties, such as tensile strength, elongation at break, work to rupture and the force by 1% of elongation were measured and analysed. The stress/strain diagrams show the differences in the behaviour under defined loads of different woven and nonwoven fabrics. The results show that the fabric with good mechanical properties is not always suitable as reinforcement, where the needle punching is used as a method of linking layers into compound fabric.

PL

W artykule przedstawiono różnice pomiędzy właściwościami mechanicznymi tkanin i włóknin oraz uwypuklono ważną rolę parametrów konstrukcyjnych, szczególnie współczynnika zapełnienia, we wzmacnianiu wyrobów kompozytowych. Podczas badań omówiono wyselekcjonowane parametry mechaniczne, takie jak wytrzymałość na zrywanie, wydłużenie przy zerwaniu, praca zrywania i siła przy jednoprocentowym wydłużeniu. Wyniki testów były przedmiotem dokładnej analizy. Wykresy naprężenia w funkcji odkształcenia obrazują różnice w zachowaniu poszczególnych tkanin i włóknin w warunkach oddziaływania określonych obciążeń. Wyniki badań wykazały, że tekstylia o dobrych właściwościach mechanicznych nie zawsze są najodpowiedniejsze jako wzmocnienie kompozytów, w tym takich w których zastosowano igłowanie jako metodę łączenia poszczególnych warstw.

8

Special model for coated woven fabrics

Ambroziak A.

Zeszyty Naukowe. Budownictwo / Politechnika Śląska

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2004

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z. 102

43-50

EN

The paper discusses the fundamental equations of the dense net model and gives the material parameters for two chosen fabrics. The special finite element procedure in the plane stress state is described to introduce effects typical for woven fabrics. Application of this model will be extended to consider the influence of coating in the proposed layered dense net model.

PL

W pracy przedstawiono podstawowe równania konstytutywne modelu sieci gęstej oraz podano parametry materiałowe dla dwu wybranych tkanin technicznych. Opisano specjalny model elementu skończonego w płaskim stanie naprężenia, który opisuje typowe właściwości tkaniny technicznej. Zastosowanie modelu będzie rozszerzone w celu uwzględnienia wpływu pokrycia w zaproponowanym warstwowym modelu sieci gęstej.

9

Modelling and simulation of the mechanical behaviour of weft-knitted fabrics for technical applications. Part IV: 3D FEA model with a mesh of tetrahedric elements

Araújo M., Fangueiro R., Hong H.

Autex Research Journal

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2004

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Vol. 4, no. 2

72--80

EN

This paper is in four parts. The first is related to general considerations and experimental analyses, and each of the others is related to different approaches to the theoretical analyses of the mechanical behaviour of weft-knitted fabrics and weft-knitted reinforced composites made of glass fibre. The objective is to find ways of improving the mechanical properties and simulating the mechanical behaviour of knitted fabrics and knitted reinforced composites so that the engineering design of such materials and structures may be improved. In Part IV the technologies for weft-knitted 3D complex shape preform development are surveyed and a third model is presented. This a 3D model based on FEA (finite element analyses). A solid representation of a 2D yarn is built up, and an MES (mechanical event simulation) is applied to obtain a 3D-shaped loop. The final knitted fabric geometry is obtained by interacting this loop with the adjacent loops, according to the dimensional properties of the knitted fabrics and using an MES. Finally, the geometry of the reinforcement inside the composite is built up, and the composite material is divided into small tetrahedric elements to obtain a mesh of finite tetrahedric elements (FEA). The average values of the mechanical properties are obtained with FEA and compared with the experimental ones.

10

Modelling and simulation of the mechanical behaviour of weft-knitted fabrics for technical applications. Part III: 2D hexagonal FEA model with non-linear truss elements

Araújo M., Fangueiro R., Hong H.

Autex Research Journal

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2004

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Vol. 4, no. 1

25--32

EN

This paper is in four parts. The first is related to general considerations and experimental analyses, and each of the others is related to different approaches to theoretical analyses of the mechanical behaviour of weft-knitted fabrics and weft-knitted reinforced composites made of glass fibre. The objective is to find ways of improving the mechanical properties and simulating the mechanical behaviour of knitted fabrics and knitted reinforced composites, so that the engineering design of such materials and structures may be improved. In Part III the second model is presented, and this is a 2D model based on FEA (finite element analyses). A plain weft-knitted fabric, based on the simple loop structure, is simplified and represented by a 2D hexagonal structure constructed by non-linear truss elements. The characteristics of the truss elements for FEA simulation are obtained from experimental results through an analytical method when a loop is converted to a FEA model. The elongation deformation is simulated in one, two and multiple directions. The model can also be used to calculate a planar knitted fabric for deformation to fit a 3D spherical mould.

11

Some theoretical models of technical woven fabric and their use in fem

Ambroziak A.

Zeszyty Naukowe. Budownictwo / Politechnika Śląska

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2003

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z. 101

47-54

EN

The paper discusses the fundamental equations describing behaviour of membrane shells used for suspension roofs. An estimation of isotropic model and dense textile net model in the analysis of technical woven fabric is carried out. The results obtained from own finite element method (FEM) code and from commercial MARC software by MSC Company are compared. Good correlation of the results between both approaches has been obtained.

PL

Celem niniejszej pracy jest: przedstawienie niektórych typów równań konstytutywnych opisujących zachowanie powłok membranowych używanych do konstrukcji przekryć wiszących. Oceniono zastosowanie modelu izotropowego i sieci gęstej w analizie tkanin technicznych. Dokonano porównania wyników uzyskanych własnymi algorytmami metody elementów skończonych z powszechnie dostępnym na rynku programem komercyjnym MARC firmy MSC. Uzyskano dobrą zgodność wyników dla obu podejść.

12

Physical parameters' identification for technical fabrics - viscoelastic mode

Komar W.

Zeszyty Naukowe. Budownictwo / Politechnika Śląska

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2003

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z. 101

191-198

EN

Practical application of technical fabrics for construction requires the knowledge of their physical properties. The constitutive models of material, particularly viscoelastic models of solid, have the essential use here. Two models have been selected (the linear standard model and its non-linear variation) and their constitutive equations have been written in one-dimensional case. Laboratory tests of uniaxial tension constant strain rate have been conducted, and the inelastic effect have been observed during them. The least squares method has been chosen for the models' parameters identification and also the fabric model - the dense net model have been chosen for further applications.

PL

Praktyczne wykorzystanie tkanin technicznych w konstruowaniu wymaga znajomości ich własności fizycznych. Konstytutywne modele materiału mają tu zasadnicze zastosowanie, a w szczególności modele lepkosprężyste ciała stałego. Spośród wielu znanych modeli wybrano dwa (liniowy model standardowy i jego wariant nieliniowy) i zapisano ich równania konstytutywne w układzie jednowymiarowym. Przeprowadzono badania laboratoryjne jednoosiowego rozciągania ze stałą prędkością odkształcenia, podczas których zaobserwowano efekt niesprężysty. Do identyfikacji parametrów modeli wybrano metodę najmniejszych kwadratów, a jako model samej tkaniny do dalszych zastosowań - model sieci gęstej.

13

Modelling and simulation of the mechanical behaviour of weft-knitted fabrics for technical applications. Part II: 3D model based on the elastica theory

Araújo M., Fangueiro R., Hong H.

Autex Research Journal

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2003

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Vol. 3, no. 4

166--172

EN

This paper is in four parts. The first is related to general considerations and experimental analyses, and each of the others is related to different approaches to the theoretical analyses of the mechanical behaviour of weft-knitted fabrics and weft-knitted reinforced composites made of glass fibre. The objective is to find ways of improving the mechanical properties and simulating the mechanical behaviour of knitted fabrics and knitted reinforced composites so that the engineering design of such materials and structures may be improved. In Part II the first model is presented, a 3D model based on the classic elastica theory which is used to calculate the load-extension curves of a plain weft-knitted fabric in the coursewise and walewise directions. Good agreement is obtained between theoretical and experimental results.

14

Modelling and simulation of the mechanical behaviour of weft-knitted fabrics for technical applications. Part I: General considerations and experimental analyses

Araújo M., Fangueiro R., Hong H.

Autex Research Journal

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2003

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Vol. 3, no. 3

111--123

EN

This paper is in four parts. The first is related to general considerations and experimental analyses, and each of the successive papers is related to different approaches to theoretical analyses of the mechanical behaviour of weft-knitted fabrics and weft-knitted reinforced composites made of glass fibre. The objective is to find ways of improving the mechanical properties and simulating the mechanical behaviour of knitted fabrics and knitted reinforced composites, so that the engineering design of such materials and structures may be improved. In Part I, general considerations, experimental analyses and ways of improving the mechanical properties of weft-knitted fabrics and knitted reinforced composites are discussed. In Part II the first model is presented, a 3D model based on the classic elastica theory, and it is used to calculate the load-extension curves of a plain weft-knitted fabric in coursewise and walewise directions. Good agreement is obtained between theoretical and experimental results. In Part III the second model is presented, a 2D model based on FEA (finite element analyses). A plain weft knitted fabric, based on the simple loop structure, is simplified and represented by a 2D hexagonal structure constructed by non-linear truss elements. The characteristics of the truss elements for FEA simulation are obtained from experimental results through an analytical method when a loop is converted to a FEA model. The elongation deformation is simulated in one, two and many directions. The model can also be used to calculate a planar knitted fabric to be deformed to fit a 3D spherical mould. In Part IV the technologies for the development of weft-knitted 3D complex shape preforms] are surveyed and a third model is presented, a 3D model based on FEA (finite element analyses). A solid representation of a 2D yarn is built up, and a MES (mechanical event simulation) is applied to obtain a 3D shaped loop. The final knitted fabric geometry is obtained by interacting this loop with the adjacent loops, according to the dimensional properties of the knitted fabrics and by using a MES. Finally, the geometry of the reinforcement inside the composite is built up, and the composite material is divided into small tetrahedric elements to obtain a mesh of finite tetrahedric elements (FEA). The average values of the mechanical properties are obtained with FEA and compared with the experimental ones.

15

Tkaniny techniczne gumowane - przykłady zastosowań

Piecyk L.

Przegląd Włókienniczy + Technik Włókienniczy

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2001

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nr 1

19-21