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1

Decoupled homogenization of hyperelastic composite with carbon black inclusion

Poręba-Sebastjan Martyna, Kuś Wacław

Computer Methods in Materials Science

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2020

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Vol. 20, No. 1

14--21

EN

The goal of the paper is to present the application of decoupled homogenization method to the modeling of hyperelastic composite with inclusions. The method presented in the paper is illustrated by numerical analysis of a trunk door seal. The decoupled homogenization method was used to find macroscale properties of hyperelastic material. The method allows for the determination of the equivalent properties of a composite material based on its structure and the results of numerical experiments. Unlike the coupled method, the results are not transferred in every iteration between scales during computations which leads to lower calculation costs. The analyzed micro model consisted of a hyperelastic matrix and stiff inclusions in the form of spheres of carbon black material. The decoupled procedure uses evolutionary algorithm to obtain macro model material properties. The finite element method is used during analyses of micro scale models.

PL

Celem pracy było zastosowanie metody homogenizacji niesprzężonej do modelowania hipersprężystego kompozytu z wtrąceniami. Metodę przedstawioną w pracy ilustruje analiza numeryczna uszczelki drzwi. Metodę homogenizacji niesprzężonej zastosowano w celu określenia makroskopowych właściwości materiału hipersprężystego. Metoda pozwala wyznaczyć równoważne właściwości materiału kompozytowego na podstawie jego struktury i wyników eksperymentów numerycznych prowadzonych w skali mikro. W przeciwieństwie do metody sprzężonej wyniki nie są przenoszone w każdej iteracji między skalami, co prowadzi do obniżenia kosztów obliczeń. Analizowany mikro model składał się z osnowy z materiału hipersprężystego oraz sztywnych wtrąceń sadzy. Metoda niesprzężona wykorzystuje algorytm ewolucyjny, aby uzyskać właściwości materiału makro. Do analiz numerycznych użyto metody elementów skończonych.

2

Investigation on flexural behaviors of i-shaped jointed composite plates

Altan Gurkan

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 2

65--70

EN

In this study, the flexural behaviors of a composite plate jointed with I profile jointing element have been carried out experimentally and numerically. As a load type, four point flexural tests have been used in order to study performances of jointed composite plates under bending load. The effects of jointing geometry parameters ratio of the width of lock to width of semi-specimen (b/W), lock middle/end width to the width of lock (z/b) and the length of lock to the width of semi-specimen (h/2W) have been investigated. According to the investigation optimum jointing parameters have been found with the h/2w ratio of 0.5, b/w ratio of 0.5 and z/b ratio of 0.5. Abaqus 6.11 finite element program has been used in order to support the results obtained from the experiments. Damages have been mostly seen on jointing lock elements.

3

Repair technology of the composite wing of a light plane damaged during an aircraft crash

Świątoniowski A., Szostak J., Chodorowska D.

Zeszyty Naukowe. Transport / Politechnika Śląska

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2016

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z. 92

149--157

EN

The increasing use of composite structures in aircraft constructions has made it necessary to develop repair methods that will restore the component’s original design strength without compromising its structural integrity. In this paper, the complex repair technology of the composite wing of a light plane, which was damaged during an aircraft crash, is described. The applied repair scheme should meet all the original design requirements for the plane structure.

4

Biological properties of nutshell and microcrystalline cellulose (MCC) filled high density polyethylene composites

Boran S., Dizman Tomak E., Dönmez Çavdar A.

Archives of Materials Science and Engineering

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2016

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Vol. 78, nr 2

71--77

EN

Purpose: The composites based on natural fibre and wood can be destroyed by fungi attack, even the lignocellulosic materials were used as filler in hydrophobic thermoplastic matrix. The aim of this study was to investigate the effect of microcrystalline cellulose (MCC) and nutshell fibre content on decay resistance of natural fibre composites. Design/methodology/approach: Half of the composite samples were immersed in water for 60 days and then incubated by fungi to investigate the leaching effect on biological resistance. Furthermore, water absorption rate and thickness swelling of samples were determined during water immersing. For this purpose, total nine thermoplastic composites filled different MCC rate (5%, 10% and 15%) and nutshell content (30%) were produced. Decay test were conducted by using a white rot fungus–Trametes versicolor, and a brown rot fungus–Tyromyces palustris, according to EN 113 standard. Findings: Based on findings from this study, weight loss, water absorption rate and thickness swelling correlated with lignocellulosic content in composites. Samples exhibited less than 1% weight loss in decay test and excellent biological resistance against testing fungi. Research limitations/implications: Weight loss (%) and moisture content (%) values of MCC-nutshell HDPE composites after Tyromyces palustris and Trametes versicolor attack were found under 3% and 20%, respectively. Low weight loss values obtained in the study are supposed to be related with the low moisture content. Originality/value: There is not a study dealing with the decay resistance of WPCs produced by a combination of nutshell and MCC fibres. In addition, there is not a substantial study on the effects of MCC/plastic ratio for decay performance of WPCs contained nutshell after long-term leaching test.

5

Problematyka oceny niezawodności węzłów tribologicznych obiektów pojedyńczych

Heinrich M., Lenkiewicz W.

Tribologia

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2001

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nr 4

591-598

PL

W opracowaniu przedstawiono metodykę badań i oceny niezawodności węzłów tribologicznych w okresie wstępnej eksploatacji obiektu pojedynczego. Podlegające szybszemu niż prognozowane zużyciu i starzeniu, węzły tarciowe powinny być modernizowane w procesach konstrukcyjno-technologicznych odpowiednio do warunków ich eksploatacji. W wyniku przeprowadzonych badań i wprowadzonych zmian badany obiekt powinien osiągnąć wymagany poziom niezawodności.

EN

In the paper is presented the process of investigation and estimation of tribological pairs reliability in the period of initial operation of a singular object. Those pairs have been frequently wearing and ageing in the shorter time then it was predicted and therefore they should be modernised in design-manufacturing processes following the real operational conditions. As a result of tests and modernisation introduced into design manufacturing solutions the investigated object has to achieve the required reliability level.