Wyniki wyszukiwania - BazTech

1

Influence of drill bit material on the bearing strength of holes in GFRP composite

Galińska Anna

Archive of Mechanical Engineering

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2023

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LXX, nr 2

287--310

EN

The article aims at assessing the influence of the drill bit material on the bearing strength of holes made in glass fabric reinforced epoxy composite. Six twists made of widely used drill materials such as high speed steels and carbides in different configurations were selected to drill holes in the composite. In the first stage of the work, optimum drilling parameters were selected and then used for drilling holes in specimens tested in single lap shear experiments. For each tested specimen two different delamination factors, one based on the delamination area and another - on its diameter, were calculated in order to assess the quality of the holes and then compared to the results of the bearing strength experiments. The results of the bearing tests showed that the highest strength was achieved for the high speed steel drill with titanium coating while the lowest for the cemented carbide drill. This finding is in opposition to the majority of results reported in literature.

2

Influence of surface treatment on the wetting process of jute fibres with thermosetting polyester resin

Bogdan-Włodek A., Kozioł M., Myalski J.

Polish Journal of Chemical Technology

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2012

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Vol. 14, nr 1

21-27

EN

The aim of this study is the evaluation of the effect of chemical treatment of jute fibres on their permeability with polyester resin and determination of optimal treatment parameters. Unmodified jute fabric by LENTEX, Poland and polyester resin ESTROMAL 14 were used in the experiments. NaOH and KOH water solutions (various concentration - from 1 to 15% - and treatment duration - from 0.5 to 6h), vinyl acetate, methanol, toluene diizocyanate were used for the treatment. Determination of the effect of the chemical treatment on fiber-resin interaction was made in: infiltration of resin into reinforcement structure tests and fabric absorbability tests. Three criteria: time of penetration of resin into the reinforcing fabric, fabric absorbability and the area of a part of the specimen cross-section penetrated with the resin were taken into account. The fabrics treated with 1-5% - long-time and 15% short-time NaOH and KOH water solutions showed the best results within the tested criteria. These results do not correspondent directly with the mechanical properties of cured composites manufactured on the base of the treated fabrics. Alkali- and organic treatments significantly improve the mechanical performance of natural fibres reinforced composites, but organic treatments (methanol, toluene diisocyanate) gives better improvement in mechanical properties in comparison with the alkali-treatments. The measurement methods applied in the study may be generally useful in the evaluation of the effect of chemical treatment of natural fibres on their wettability with the liquid matrix.

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Influence of wet chemistry treatment on the mechanical performance of natural fibres

Koziol M., Bogdan-Wlodek A., Myalski J., Wieczorek J.

Polish Journal of Chemical Technology

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2011

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Vol. 13, nr 4

21-27

EN

The paper presents determination of the effect of various chemical treatment on the strength of 288 tex jute yarn arisen from the plain weave fabric produced by LENTEX, Poland. The yarn was put to alternative treatments in: NaOH and KOH water solutions with various concentration (from 1 to 15%) and treatment duration (from 0.5 to 6 hours), vinyl acetate, methanol and toluene diisocyanate. After the treatment it was put to tensile tests. Yarn diameter and elementary fibre twist angle were also measured using MICRO PROF FRT optical profilographometer. The SEM micro-photographs have also been performed in order to evaluate the structural changes of the yarn after the treatment. Optimal conditions of alcali-treatment are: 5% concentration and 2h duration for NaOH, 3% concentration and 4h duration for KOH. Such treatments give a growth in yarn rupture force up to 10% and they are well applicable in composite materials manufacturing. Also interaction with vinyl acetate and toluene diisocyanate has practically not negative influence on the mechanical performance of the yarn. Two effects were observed which can explain the influence of chemical treatment on mechanical performance of jute yarn: swelling and change in the orientation of elementary fibres.

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Kompozyty włókniste - właściwości, zastosowanie, obróbka ubytkowa

Oczoś K. E.

Mechanik

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2008

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R. 81, nr 7

579-592

PL

Budowa kompozytów włóknistych. Kompozyty z osnową polimerową, metalową i ceramiczną. Zastosowanie kompozytów włóknistych w przemyśle lotniczym i samochodowym. Problemy obróbkowe kompozytów włóknistych i sposoby ich przezwyciężania. Narzędzia do skrawania kompozytów włóknistych.

EN

Fiber matrix composites. Composite materials using polymer, metal or ceramic matrices. Application of fiber matrix composite materials in aircraft and in automotive industries. Problems occurring in the fiber matrix composites machining operations and counter-measure methods. Tools used for machining fiber matrix composites.

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Trefftz radial basis functions (TRBF)

Kompiš V., Štiavnicky M., Žmindák M., Murčinková Z.

Computer Assisted Mechanics and Engineering Sciences

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2008

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Vol. 15, No. 3/4

239-249

EN

The TRBF's are radial functions satisfying governing equation in the domain. They can be used as interpolation functions of the field variables especially in boundary methods. In present paper discrete dipoles are used to simulate composite material reinforced by stiff particles using with boundary point collocation method which does not require any meshing and any integration. The better the interpolation (unction satisfies also the boundary conditions, the more efficient it is. In examples it is shown that a triple dipole (which is a TRBK) located into the center of the particle can approximate the inter-domain boundary conditions very good, if the particles are not very close to each other and their size is not very different. In general problem the model can be used as very good start point for international improvements in refined model. (Composite reinforced by short fibres with very large aspect ratio continuous TRBF were developed. They enable to reduce problem considerably and to simulate complicated interactions for investigation such composites.