36 research outputs found

    Evaluation of circumferential properties of Jute/Epoxy tubes manufactured by filament winding based on the fiber orientation.

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    The introduction of bio-composites in the manufacture of tubes by the filament winding technique poses a real challenge for design engineers. This study aims to evaluate the mechanical properties in circumferential traction and in circumferential compression of Jute-Epoxy tubes whose winding angle is considered to be variable. The experimental study is carried out on 6 tube configurations of 92 mm in diameter. The tubes tested are made of 4 layers. The selected Ξ± fiber winding angles are (50 Β°, 55 Β°, 60 Β°, 65 Β°, 75 Β°, and 90 Β°). Circumferential tensile and stiffness tests are established according to the specifications of ASTM D2290 and ASTM D2412 respectively. The results obtained allowed us to analyze the influence of the winding angle on the properties of the tubes

    Evaluation of circumferential properties of Jute/Epoxy tubes manufactured by filament winding based on the fiber orientation.

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    The introduction of bio-composites in the manufacture of tubes by the filament winding technique poses a real challenge for design engineers. This study aims to evaluate the mechanical properties in circumferential traction and in circumferential compression of Jute-Epoxy tubes whose winding angle is considered to be variable. The experimental study is carried out on 6 tube configurations of 92 mm in diameter. The tubes tested are made of 4 layers. The selected Ξ± fiber winding angles are (50 Β°, 55 Β°, 60 Β°, 65 Β°, 75 Β°, and 90 Β°). Circumferential tensile and stiffness tests are established according to the specifications of ASTM D2290 and ASTM D2412 respectively. The results obtained allowed us to analyze the influence of the winding angle on the properties of the tubes

    The physicomechanical and thermal properties of Algerian Aleppo pine (Pinus halepensis) wood as a component of sandwich panels

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    Research ArticleAleppo pine (Pinus halepensis Mill.) is the main forest species of Algeria occupying more than 35% of the total forest area of the country. However, the physicomechanical and thermal characteristics of Algerian P. halepensis wood are not well-known. This research investigates the physical (moisture, density, swelling, and shrinkage), mechanical (bending strength and modulus of elasticity), and thermal (mass loss under combustion and pyrolysis as well as thermal conductivity) properties of P. halepensis wood from the Darguina (Bejaia) forest in Algeria. The results showed that Algerian P. halepensis wood with a mean density of 540 kg m-3 has good dimensional stability in swelling and shrinkage, with 116.43 MPa bending strength and a modulus of elasticity of 17,520 MPa. The wood shows a good thermal resistance under low-temperature range and has a thermal conductivity of 0.21 W m-1 K-1. The overall results indicate that Algerian P. halepensis wood may be commercially exploited for construction and insulation applications, namely in the production of sandwich compositesinfo:eu-repo/semantics/publishedVersio

    Flexural Fatigue Behavior of Cross-Ply Laminates: An Experimental Approach

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    Within an experimental approach we describe the mechanical behavior of different resin-epoxy laminates reinforced with cross-ply Kevlar and glass fibers under the conditions of static and cyclic three-point bending. In static tests, we consider the effect of stacking sequence, the thickness of 90Β°-oriented layers, reinforcement type on the mechanical behavior of laminates under loading and on realization of various damage modes leading to rupture. Cyclic loading studies have been performed in two steps. In the first stage, we inquire into the dependence of the behavior and durability of four glass fiber- reinforced laminate-types on the stacking sequence; the second stage is devoted to studying the dependence of cyclic strength and fatigue behavior of laminates on the reinforcement type. Fatigue tests are carried out in load-control regime for glass and hybrid (Kevlar + glass) fiber laminates. Fatigue curves are constructed in coordinates β€œstress - number of cycles until fracture” from the criteria corresponding to a drop in stiffness by 5 and 10%. Analysis of the results obtained permits evaluation of the effect of the stacking sequence and the reinforcement type on the behavior of cross-ply laminates in cyclic loading. The presence of Kevlar fibers accounts for nonlinear behavior of laminates in static tests and for low cyclic strength in fatigue tests under three-point bending.Π’ Ρ€Π°ΠΌΠΊΠ°Ρ… ΡΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ ΠΏΠΎΠ΄Ρ…ΠΎΠ΄Π° описано мСханичСскоС ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… Π»Π°ΠΌΠΈΠ½Π°Ρ‚ΠΎΠ² с ΠΌΠ°Ρ‚Ρ€ΠΈΡ†Π΅ΠΉ ΠΈΠ· эпоксидной смолы, пСрСкрСстно-Π°Ρ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Ρ… ΠΊΠ΅Π²Π»Π°Ρ€ΠΎΠ²Ρ‹ΠΌΠΈ Π²ΠΎΠ»ΠΎΠΊΠ½Π°ΠΌΠΈ ΠΈ стСкловолокнами, Π² условиях статичСского ΠΈ цикличСского Ρ‚Ρ€Π΅Ρ…Ρ‚ΠΎΡ‡Π΅Ρ‡Π½ΠΎΠ³ΠΎ ΠΈΠ·Π³ΠΈΠ±Π°. ΠŸΡ€ΠΈ статичСских испытаниях Ρ€Π°ΡΡΠΌΠ°Ρ‚Ρ€ΠΈΠ²Π°ΡŽΡ‚ΡΡ ΠΏΠΎΡΠ»Π΅Π΄ΠΎΠ²Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΡŒ ΡƒΠΊΠ»Π°Π΄ΠΊΠΈ слоСв ΠΈ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½, Ρ‚ΠΎΠ»Ρ‰ΠΈΠ½Ρ‹ слоСв, ΠΎΡ€ΠΈΠ΅Π½Ρ‚ΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Ρ… ΠΏΠΎΠ΄ ΡƒΠ³Π»ΠΎΠΌ 90Β° ΠΈ влияниС Ρ‚ΠΈΠΏΠ° армирования Π½Π° мСханичСскоС ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ Π»Π°ΠΌΠΈΠ½Π°Ρ‚ΠΎΠ² Π² процСссС нагруТСния, Π° Ρ‚Π°ΠΊΠΆΠ΅ Π½Π° Ρ€Π΅Π°Π»ΠΈΠ·Π°Ρ†ΠΈΡŽ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… Ρ€Π΅ΠΆΠΈΠΌΠΎΠ² поврСТдСния, приводящих ΠΊ Ρ€Π°Π·Ρ€ΡƒΡˆΠ΅Π½ΠΈΡŽ. ИсслСдования ΠΏΡ€ΠΈ цикличСском Π½Π°Π³Ρ€ΡƒΠΆΠ΅Π½ΠΈΠΈ состоят ΠΈΠ· Π΄Π²ΡƒΡ… этапов. На ΠΏΠ΅Ρ€Π²ΠΎΠΌ этапС изучаСтся влияниС ΠΏΠΎΡΠ»Π΅Π΄ΠΎΠ²Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ ΡƒΠΊΠ»Π°Π΄ΠΊΠΈ слоСв ΠΈ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½ Π½Π° ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΠΈ Π΄ΠΎΠ»Π³ΠΎΠ²Π΅Ρ‡Π½ΠΎΡΡ‚ΡŒ Ρ‡Π΅Ρ‚Ρ‹Ρ€Π΅Ρ… Ρ‚ΠΈΠΏΠΎΠ² Π»Π°ΠΌΠΈΠ½Π°Ρ‚ΠΎΠ², Π°Ρ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Ρ… стСкловолокнами, Π½Π° Π²Ρ‚ΠΎΡ€ΠΎΠΌ этапС - влияниС Ρ‚ΠΈΠΏΠ° армирования Π½Π° Ρ†ΠΈΠΊΠ»ΠΈΡ‡Π΅ΡΠΊΡƒΡŽ ΠΏΡ€ΠΎΡ‡Π½ΠΎΡΡ‚ΡŒ ΠΈ сопротивлСниС Π»Π°ΠΌΠΈΠ½Π°Ρ‚ΠΎΠ² ΠΏΡ€ΠΈ цикличСском Π½Π°Π³Ρ€ΡƒΠΆΠ΅Π½ΠΈΠΈ. УсталостныС испытания Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½Ρ‹ Π² мягком Ρ€Π΅ΠΆΠΈΠΌΠ΅ нагруТСния для Π»Π°ΠΌΠΈΠ½Π°Ρ‚ΠΎΠ², Π°Ρ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Ρ… стСкловолокнами ΠΈ Π³ΠΈΠ±Ρ€ΠΈΠ΄Π½Ρ‹ΠΌΠΈ Π²ΠΎΠ»ΠΎΠΊΠ½Π°ΠΌΠΈ (ΠΊΠ΅Π²Π»Π°Ρ€+стСкло). ΠšΡ€ΠΈΠ²Ρ‹Π΅ усталости Π±Ρ‹Π»ΠΈ построСны Π² ΠΊΠΎΠΎΡ€Π΄ΠΈΠ½Π°Ρ‚Π°Ρ… напряТСниС - число Ρ†ΠΈΠΊΠ»ΠΎΠ² Π΄ΠΎ Ρ€Π°Π·Ρ€ΡƒΡˆΠ΅Π½ΠΈΡ Π½Π° основС ΠΊΡ€ΠΈΡ‚Π΅Ρ€ΠΈΠ΅Π² сниТСния ТСсткости Π½Π° 5 ΠΈ 10%. Анализ ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Π½Ρ‹Ρ… Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚ΠΎΠ² позволяСт ΠΎΡ†Π΅Π½ΠΈΡ‚ΡŒ влияниС ΠΏΠΎΡΠ»Π΅Π΄ΠΎΠ²Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ ΡƒΠΊΠ»Π°Π΄ΠΊΠΈ слоСв ΠΈ Ρ‚ΠΈΠΏΠ° армирования Π½Π° ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ пСрСкрСстно-Π°Ρ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Ρ… Π»Π°ΠΌΠΈΠ½Π°Ρ‚ΠΎΠ² ΠΏΡ€ΠΈ цикличСском Π½Π°Π³Ρ€ΡƒΠΆΠ΅Π½ΠΈΠΈ. НаличиС ΠΊΠ΅Π²Π»Π°Ρ€ΠΎΠ²Ρ‹Ρ… Π²ΠΎΠ»ΠΎΠΊΠΎΠ½ Π² Π»Π°ΠΌΠΈΠ½Π°Ρ‚Π°Ρ… обСспСчиваСт ΠΈΡ… Π½Π΅Π»ΠΈΠ½Π΅ΠΉΠ½ΠΎΠ΅ ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΠΏΡ€ΠΈ статичСских испытаниях ΠΈ Π½ΠΈΠ·ΠΊΡƒΡŽ Ρ†ΠΈΠΊΠ»ΠΈΡ‡Π΅ΡΠΊΡƒΡŽ ΠΏΡ€ΠΎΡ‡Π½ΠΎΡΡ‚ΡŒ ΠΏΡ€ΠΈ усталостных испытаниях Π² условиях Ρ‚Ρ€Π΅Ρ…Ρ‚ΠΎΡ‡Π΅Ρ‡Π½ΠΎΠ³ΠΎ ΠΈΠ·Π³ΠΈΠ±Π°.Π£ Ρ€Π°ΠΌΠΊΠ°Ρ… Π΅ΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ ΠΏΡ–Π΄Ρ…ΠΎΠ΄Ρƒ описано ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½Ρƒ ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ Ρ€Ρ–Π·Π½ΠΈΡ… Π»Π°ΠΌΡ–Π½Π°Ρ‚Ρ–Π² Ρ–Π· ΠΌΠ°Ρ‚Ρ€ΠΈΡ†Π΅ΡŽ Π· Споксидної смоли, Ρ‰ΠΎ пСрСхрСсноармовані ΠΊΠ΅Π²Π»Π°Ρ€ΠΎ- Π²ΠΈΠΌΠΈ Π²ΠΎΠ»ΠΎΠΊΠ½Π°ΠΌΠΈ Ρ– скловолокнами, Π² ΡƒΠΌΠΎΠ²Π°Ρ… статичного Ρ– Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½ΠΎΠ³ΠΎ Ρ‚Ρ€ΠΈ- Ρ‚ΠΎΡ‡ΠΊΠΎΠ²ΠΎΠ³ΠΎ Π·Π³ΠΈΠ½Ρƒ. ΠŸΡ€ΠΈ статичних випробуваннях Ρ€ΠΎΠ·Π³Π»ΡΠ΄Π°ΡŽΡ‚ΡŒΡΡ ΠΏΠΎΡΠ»Ρ–Π΄ΠΎΠ²Π½Ρ–ΡΡ‚ΡŒ укладСння ΡˆΠ°Ρ€Ρ–Π² Ρ– Π²ΠΎΠ»ΠΎΠΊΠΎΠ½, Ρ‚ΠΎΠ²Ρ‰ΠΈΠ½ΠΈ ΠΎΡ€Ρ–Ρ”Π½Ρ‚ΠΎΠ²Π°Π½ΠΈΡ… ΠΏΡ–Π΄ ΠΊΡƒΡ‚ΠΎΠΌ 90Β° ΡˆΠ°Ρ€Ρ–Π² Ρ– Π²ΠΏΠ»ΠΈΠ² Ρ‚ΠΈΠΏΡƒ армування Π½Π° ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½Ρƒ ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ Π»Π°ΠΌΡ–Π½Π°Ρ‚Ρ–Π² Ρƒ процСсі навантаТСння, Π° Ρ‚Π°ΠΊΠΎΠΆ Π½Π° Ρ€Π΅Π°Π»Ρ–Π·Π°Ρ†Ρ–ΡŽ Ρ€Ρ–Π·Π½ΠΈΡ… Ρ€Π΅ΠΆΠΈΠΌΡ–Π² пошкодТСння, Ρ‰ΠΎ ΠΏΡ€ΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚ΡŒ Π΄ΠΎ руйнування. ДослідТСння ΠΏΡ€ΠΈ Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½ΠΎΠΌΡƒ Π½Π°Π²Π°Π½Ρ‚Π°ΠΆΠ΅Π½Π½Ρ– ΡΠΊΠ»Π°Π΄Π°Ρ”Ρ‚ΡŒΡΡ Π· Π΄Π²ΠΎΡ… Π΅Ρ‚Π°ΠΏΡ–Π². На ΠΏΠ΅Ρ€ΡˆΠΎΠΌΡƒ Π΅Ρ‚Π°ΠΏΡ– Ρ€ΠΎΠ·Π³Π»ΡΠ΄Π°Ρ”Ρ‚ΡŒΡΡ Π²ΠΏΠ»ΠΈΠ² послідовності укладСння ΡˆΠ°Ρ€Ρ–Π² Ρ– Π²ΠΎΠ»ΠΎΠΊΠΎΠ½ Π½Π° ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ Ρ– Π΄ΠΎΠ²Π³ΠΎΠ²Ρ–Ρ‡Π½Ρ–ΡΡ‚ΡŒ Ρ‡ΠΎΡ‚ΠΈΡ€ΡŒΠΎΡ… Ρ‚ΠΈΠΏΡ–Π² Π°Ρ€ΠΌΠΎΠ²Π°Π½ΠΈΡ… скловолокнами Π»Π°ΠΌΡ–Π½Π°Ρ‚Ρ–Π², Π½Π° Π΄Ρ€ΡƒΠ³ΠΎΠΌΡƒ Π΅Ρ‚Π°ΠΏΡ– - Π²ΠΏΠ»ΠΈΠ² Ρ‚ΠΈΠΏΡƒ армування Π½Π° Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½Ρƒ ΠΌΡ–Ρ†Π½Ρ–ΡΡ‚ΡŒ Ρ– ΠΎΠΏΡ–Ρ€ Π»Π°ΠΌΡ–Π½Π°Ρ‚Ρ–Π² ΠΏΡ€ΠΈ Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½ΠΎΠΌΡƒ Π½Π°Π²Π°Π½Ρ‚Π°ΠΆΠ΅Π½Π½Ρ–. Випробування Π½Π° Π²Ρ‚ΠΎΠΌΡƒ Π²ΠΈΠΊΠΎΠ½Π°Π½ΠΎ Ρƒ ΠΌ ’якому Ρ€Π΅ΠΆΠΈΠΌΡ– навантаТСння для Π°Ρ€ΠΌΠΎΠ²Π°Π½ΠΈΡ… скловолокнами Ρ– Π³Ρ–Π±Ρ€ΠΈΠ΄Π½ΠΈΠΌΠΈ Π²ΠΎΠ»ΠΎΠΊΠ½Π°ΠΌΠΈ (ΠΊΠ΅Π²Π»Π°Ρ€ + скло) Π»Π°ΠΌΡ–Π½Π°Ρ‚Ρ–Π². На основі ΠΊΡ€ΠΈΡ‚Π΅Ρ€Ρ–Ρ—Π² зниТСння Торсткості Π½Π° 5 Ρ– 10% Π² ΠΊΠΎΠΎΡ€Π΄ΠΈΠ½Π°Ρ‚Π°Ρ… напруТСння - число Ρ†ΠΈΠΊΠ»Ρ–Π² Π΄ΠΎ руйнування ΠΏΠΎΠ±ΡƒΠ΄ΠΎΠ²Π°Π½ΠΎ ΠΊΡ€ΠΈΠ²Ρ– ΡƒΡ‚ΠΎΠΌΠΈ. Аналіз ΠΎΡ‚Ρ€ΠΈΠΌΠ°Π½ΠΈΡ… Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ–Π² дозволяє ΠΎΡ†Ρ–Π½ΠΈΡ‚ΠΈ Π²ΠΏΠ»ΠΈΠ² послідовності укладСння ΡˆΠ°Ρ€Ρ–Π² Ρ– Ρ‚ΠΈΠΏΡƒ армування Π½Π° ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ пСрСхрСсноармованих Π»Π°ΠΌΡ–Π½Π°Ρ‚Ρ–Π² ΠΏΡ€ΠΈ Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½ΠΎΠΌΡƒ Π½Π°Π²Π°Π½Ρ‚Π°ΠΆΠ΅Π½Π½Ρ–. ΠΠ°ΡΠ²Π½Ρ–ΡΡ‚ΡŒ ΠΊΠ΅Π²Π»Π°Ρ€ΠΎΠ²ΠΈΡ… Π²ΠΎΠ»ΠΎΠΊΠΎΠ½ Ρƒ Π»Π°ΠΌΡ–Π½Π°Ρ‚Π°Ρ… Π·Π°ΠΏΠ΅Π·Ρ‡ΡƒΡ” Ρ—Ρ… Π½Π΅Π»Ρ–Π½Ρ–ΠΉΠ½Ρƒ ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ ΠΏΡ€ΠΈ статичних випробуваннях Ρ– Π½ΠΈΠ·ΡŒΠΊΡƒ Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½Ρƒ ΠΌΡ–Ρ†Π½Ρ–ΡΡ‚ΡŒ ΠΏΡ€ΠΈ випробуваннях Π½Π° Π²Ρ‚ΠΎΠΌΡƒ Π² ΡƒΠΌΠΎΠ²Π°Ρ… Ρ‚Ρ€ΠΈΡ‚ΠΎΡ‡ΠΊΠΎΠ²ΠΎΠ³ΠΎ Π·Π³ΠΈΠ½Ρƒ

    Experimental analysis of behavior and damage of sandwich composite materials in three-point bending. Part 1. Static tests and stiffness degradation at failure studies

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    The analysis of stiffness and the identification of rupture mechanisms during and after static tests of sandwich panels and their components have been investigated. The sandwich panels, having cross-ply laminates skins made of glass fibre and epoxy resin were manufactured by vacuum moulding and subjected to three-point bending tests. Two PVC cores of similar type but with differing densities were investigated. The effect of core density and its thickness on the behavior and the damage was highlighted. In terms of stiffness and load at failure, the sandwich structure has better mechanical characteristics compared to its components.Π•ΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½ΠΎ дослідТСно Π·ΠΌΡ–Π½Ρƒ Торсткості Ρ‚Π° ΠΏΡ€ΠΎΠ°Π½Π°Π»Ρ–Π·ΠΎΠ²Π°Π½ΠΎ ΠΌΠ΅Ρ…Π°Π½Ρ–Π·ΠΌΠΈ руйнування ΠΏΡ€ΠΈ статичних випробуваннях Π±Π°Π³Π°Ρ‚ΠΎΡˆΠ°Ρ€ΠΎΠ²ΠΈΡ… ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½ΠΈΡ… пластин Ρ– Ρ—Ρ… ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½Ρ‚Ρ–Π². Π‘Π°Π³Π°Ρ‚ΠΎΡˆΠ°Ρ€ΠΎΠ²Ρ– ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½Ρ– пластини Π· пСрСхрСсними ΡˆΠ°Ρ€Π°ΠΌΠΈ Π·Ρ– скловолокна Ρ‚Π° Споксидної смоли, Ρ‰ΠΎ Π²ΠΈΠ³ΠΎΡ‚ΠΎΠ²Π»Π΅Π½Ρ– ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ Π²Π°ΠΊΡƒΡƒΠΌΠ½ΠΎΡ— Π²Ρ–Π΄Π»ΠΈΠ²ΠΊΠΈ, ΠΏΡ–Π΄Π΄Π°Π²Π°Π»ΠΈ Π½Π°Π²Π°Π½Ρ‚Π°ΠΆΠ΅Π½Π½ΡŽ Ρ‚Ρ€ΠΈΡ‚ΠΎΡ‡ΠΊΠΎΠ²ΠΈΠΌ Π·Π³ΠΈΠ½ΠΎΠΌ. ДослідТували Π΄Π²Π° Π²Π°Ρ€Ρ–Π°Π½Ρ‚ΠΈ пластин Π· ΠΎΠ΄Π½ΠΎΡ‚ΠΈΠΏΠ½ΠΈΠΌΠΈ Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π°ΠΌΠΈ Π· ΠΏΠΎΠ»Ρ–- вінілопласта Ρ€Ρ–Π·Π½ΠΎΡ— Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ–. Розглянуто Π²ΠΏΠ»ΠΈΠ² Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ– Ρ– Ρ‚ΠΎΠ²Ρ‰ΠΈΠ½ΠΈ Π²Π½ΡƒΡ‚Ρ€Ρ–ΡˆΠ½ΡŒΠΎΠ³ΠΎ ΡˆΠ°Ρ€Ρƒ Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π° Π½Π° ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ Ρ‚Π° пошкодТСння ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π°. Показано, Ρ‰ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ Ρ–Π· Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π΅ΠΌ Π²Π΅Π»ΠΈΠΊΠΎΡ— Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ– ΠΌΠ°Ρ” Π±Ρ–Π»ΡŒΡˆ високі характСристики статичної міцності Ρ– стійкості порівняно Π· ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ΠΎΠΌ Ρ–Π· Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π΅ΠΌ ΠΌΠ΅Π½ΡˆΠΎΡ— Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ–.Π­ΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½ΠΎ исслСдовано ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ ТСсткости ΠΈ ΠΏΡ€ΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Π½Ρ‹ ΠΌΠ΅Ρ…Π°Π½ΠΈΠ·ΠΌΡ‹ Ρ€Π°Π·Ρ€ΡƒΡˆΠ΅Π½ΠΈΡ ΠΏΡ€ΠΈ статичСских испытаниях многослойных ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½Ρ‹Ρ… пластин ΠΈ ΠΈΡ… ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½Ρ‚ΠΎΠ². ΠœΠ½ΠΎΠ³ΠΎΡΠ»ΠΎΠΉΠ½Ρ‹Π΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½Ρ‹Π΅ пластины с пСрСкрСстными слоями ΠΈΠ· стСкловолокна ΠΈ эпоксидной смолы, ΠΈΠ·Π³ΠΎΡ‚ΠΎΠ²Π»Π΅Π½Π½Ρ‹Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ Π²Π°ΠΊΡƒΡƒΠΌΠ½ΠΎΠΉ ΠΎΡ‚Π»ΠΈΠ²ΠΊΠΈ, ΠΏΠΎΠ΄Π²Π΅Ρ€Π³Π°Π»ΠΈ Π½Π°Π³Ρ€ΡƒΠΆΠ΅Π½ΠΈΡŽ Ρ‚Ρ€Π΅Ρ…Ρ‚ΠΎΡ‡Π΅Ρ‡Π½Ρ‹ΠΌ ΠΈΠ·Π³ΠΈΠ±ΠΎΠΌ. ИсслСдовали Π΄Π²Π° Π²Π°Ρ€ΠΈΠ°Π½Ρ‚Π° пластин с ΠΎΠ΄Π½ΠΎΡ‚ΠΈΠΏΠ½Ρ‹ΠΌΠΈ наполнитСлями ΠΈΠ· пСновинилопласта Ρ€Π°Π·Π»ΠΈΡ‡Π½ΠΎΠΉ плотности. РассмотрСно влияниС плотности ΠΈ Ρ‚ΠΎΠ»Ρ‰ΠΈΠ½Ρ‹ Π²Π½ΡƒΡ‚Ρ€Π΅Π½Π½Π΅Π³ΠΎ слоя наполнитСля Π½Π° ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΠΈ ΠΏΠΎΠ²Ρ€Π΅ΠΆΠ΄Π΅Π½ΠΈΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π°. Показано, Ρ‡Ρ‚ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ с Π½Π°ΠΏΠΎΠ»Π½ΠΈΡ‚Π΅Π»Π΅ΠΌ большСй плотности ΠΎΠ±Π»Π°Π΄Π°Π΅Ρ‚ Π±ΠΎΠ»Π΅Π΅ высокими характСристиками статичСской прочности ΠΈ устойчивости ΠΏΠΎ ΡΡ€Π°Π²Π½Π΅Π½ΠΈΡŽ с ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ΠΎΠΌ, ΠΈΠΌΠ΅ΡŽΡ‰ΠΈΠΌ Π½Π°ΠΏΠΎΠ»Π½ΠΈΡ‚Π΅Π»ΡŒ мСньшСй плотности

    Experimental Analysis of Behavior and Damage of Sandwich Composite Materials in Three-Point Bending. Part 2. Fatigue Test Results and Damage Mechanisms

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    Π’Ρ‹ΠΏΠΎΠ»Π½Π΅Π½Ρ‹ ΡΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½Ρ‹Π΅ исслСдования измСнСния ТСсткости ΠΈ ΠΌΠ΅Ρ…Π°Π½ΠΈΠ·ΠΌΠΎΠ² поврСТ­дСния ΠΏΡ€ΠΈ усталостных испытаниях многослойных ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½ΠΈΡ… пластин с Π½Π°ΠΏΠΎΠ»Π½ΠΈΡ‚Π΅Π»Π΅ΠΌ ΠΈΠ· пСновинилопласта. ΠœΠ½ΠΎΠ³ΠΎΡΠ»ΠΎΠΈΜ†Π½Ρ‹Π΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½Ρ‹Π΅ пластины с пСрСкрСстными слоями ΠΈΠ· стСкло­ Π²ΠΎΠ»ΠΎΠΊΠ½Π° ΠΈ эпоксидной смолы, ΠΈΠ·Π³ΠΎΡ‚ΠΎΠ²Π»Π΅Π½Π½Ρ‹Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ Π²Π°ΠΊΡƒΡƒΠΌΠ½ΠΎΠΈΜ† ΠΎΡ‚Π»ΠΈΠ²ΠΊΠΈ, ΠΏΠΎΠ΄Π²Π΅Ρ€Π³Π°Π»ΠΈ Π½Π°Π³Ρ€ΡƒΒ­ΠΆΠ΅Π½ΠΈΡŽ Ρ‚Ρ€Π΅Ρ…Ρ‚ΠΎΡ‡Π΅Ρ‡Π½Ρ‹ΠΌ ΠΈΠ·Π³ΠΈΠ±ΠΎΠΌ. ИсслСдовали Π΄Π²Π° Π²Π°Ρ€ΠΈΠ°Π½Ρ‚Π° пластин с ΠΎΠ΄Π½ΠΎΡ‚ΠΈΠΏΠ½Ρ‹ΠΌΠΈ напол­нитСлями ΠΈΠ· пСновинилопласта Ρ€Π°Π·Π»ΠΈΡ‡Π½ΠΎΠΈΜ† плотности. РассмотрСно влияниС плотности ΠΈ Ρ‚ΠΎΠ»Ρ‰ΠΈΠ½Ρ‹ Π²Π½ΡƒΡ‚Ρ€Π΅Π½Π½Π΅Π³ΠΎ слоя наполнитСля Π½Π° ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΠΈ ΠΏΠΎΠ²Ρ€Π΅ΠΆΠ΄Π΅Π½ΠΈΠ΅ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π°. Π‘ исполь­зованиСм Π΄Π²ΡƒΡ…Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… ΠΌΠΎΠ΄Π΅Π»Π΅ΠΈΜ† ΠΈ критСрия цикличСской долговСчности построСны ΠΊΡ€ΠΈΠ²Ρ‹Π΅ усталости ΠΈ Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½ ΠΈΡ… ΡΡ€Π°Π²Π½ΠΈΡ‚Π΅Π»ΡŒΠ½Ρ‹ΠΈΜ† Π°Π½Π°Π»ΠΈΠ· с ΠΈΠΌΠ΅ΡŽΡ‰ΠΈΠΌΠΈΡΡ Π»ΠΈΡ‚Π΅Ρ€Π°Ρ‚ΡƒΡ€Π½Ρ‹ΠΌΠΈ Π΄Π°Π½Π½Ρ‹ΠΌΠΈ. Показано, Ρ‡Ρ‚ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ SD 2 с Π½Π°ΠΏΠΎΠ»Π½ΠΈΡ‚Π΅Π»Π΅ΠΌ Π±ΠΎΠ»ΡŒΡˆΠ΅ΠΈΜ† плотности ΠΎΠ±Π»Π°Π΄Π°Π΅Ρ‚ Π±ΠΎΠ»Π΅Π΅ высокими характСристиками статичСской прочности ΠΈ устойчивости, Π° Ρ‚Π°ΠΊΠΆΠ΅ усталостной проч­ности ΠΏΠΎ ΡΡ€Π°Π²Π½Π΅Π½ΠΈΡŽ с ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ΠΎΠΌ SD 1 с Π½Π°ΠΏΠΎΠ»Π½ΠΈΡ‚Π΅Π»Π΅ΠΌ ΠΌΠ΅Π½ΡŒΡˆΠ΅ΠΈΜ† плотности.ΠŸΡ€ΠΎΠ²Π΅Π΄Π΅Π½ΠΎ Π΅ΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½Ρ– дослідТСння Π·ΠΌΡ–Π½ΠΈ Торсткості Ρ‚Π° ΠΌΠ΅Ρ…Π°Π½Ρ–Π·ΠΌΡ–Π² пошкодТСння ΠΏΡ€ΠΈ випробуваннях Π½Π° Π²Ρ‚ΠΎΠΌΡƒ Π±Π°Π³Π°Ρ‚ΠΎΡˆΠ°Ρ€ΠΎΠ²ΠΈΡ… ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½ΠΈΡ… пластин Ρ–Π· Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π΅ΠΌ Ρ–Π· піновінілопласта. Π‘Π°Π³Π°Ρ‚ΠΎΡˆΠ°Ρ€ΠΎΠ²Ρ– ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π½Ρ– пластини Π· пСрСхрСсними ΡˆΠ°Ρ€Π°ΠΌΠΈ Π·Ρ– скловолокна Ρ‚Π° Споксидної смоли, Π²ΠΈΠ³ΠΎΡ‚ΠΎΠ²Π»Π΅Π½Ρ– ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ Π²Π°ΠΊΡƒΡƒΠΌΠ½ΠΎΠ³ΠΎ Π²Ρ–Π΄Π»ΠΈΠ²Ρƒ, ΠΏΡ–Π΄Π΄Π°Π²Π°Π»ΠΈ Π½Π°Π²Π°Π½Ρ‚Π°ΠΆΠ΅Π½Π½ΡŽ Ρ‚Ρ€ΠΈΡ‚ΠΎΡ‡ΠΊΠΎΠ²ΠΈΠΌ Π·Π³ΠΈΠ½ΠΎΠΌ. ДослідТували Π΄Π²Π° Π²Π°Ρ€Ρ–Π°Π½Ρ‚Π° пластин Π· ΠΎΠ΄Π½ΠΎΡ‚ΠΈΠΏΠ½ΠΈΠΌΠΈ Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π°ΠΌΠΈ Π· піновінілопласта Ρ€Ρ–Π·Π½ΠΎΡ— Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ–. Розглянуто Π²ΠΏΠ»ΠΈΠ² Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ– Ρ– Ρ‚ΠΎΠ²Ρ‰ΠΈΠ½ΠΈ Π²Π½ΡƒΡ‚Ρ€Ρ–ΡˆΠ½ΡŒΠΎΠ³ΠΎ ΡˆΠ°Ρ€Ρƒ Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π° Π½Π° ΠΏΠΎΠ²Π΅Π΄Ρ–Π½ΠΊΡƒ Ρ‚Π° пошкодТСння ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚Π°. Π†Π· використанням Π΄Π²ΠΎΡ… Ρ€Ρ–Π·Π½ΠΈΡ… ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ Ρ‚Π° ΠΊΡ€ΠΈΡ‚Π΅Ρ€Ρ–ΡŽ Ρ†ΠΈΠΊΠ»Ρ–Ρ‡Π½ΠΎΡ— довговічності ΠΏΠΎΠ±ΡƒΠ΄ΠΎΠ²Π°Π½ΠΎ ΠΊΡ€ΠΈΠ²Ρ– втомлСності Ρ– ΠΏΡ€ΠΎΠ²Π΅Π΄Π΅Π½ΠΎ Ρ—Ρ… ΠΏΠΎΡ€Ρ–Π²Π½ΡΠ»ΡŒΠ½ΠΈΠΉ Π°Π½Π°Π»Ρ–Π· Ρ–Π· Π²Ρ–Π΄ΠΎΠΌΠΈΠΌΠΈ Π»Ρ–Ρ‚Π΅Ρ€Π°Ρ‚ΡƒΡ€Π½ΠΈΠΌΠΈ Π΄Π°Π½ΠΈΠΌΠΈ. Показано, Ρ‰ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ SD 2 Π· Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π΅ΠΌ Π²Π΅Π»ΠΈΠΊΠΎΡ— Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ– ΠΌΠ°Ρ” Π±Ρ–Π»ΡŒΡˆ високі характСристики статичної міцності Ρ– стійкості Ρ‚Π° ΡƒΡ‚ΠΎΠΌΠ½ΠΎΡ— міцності порівняно Π· ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡ‚ΠΎΠΌ SD 1 Ρ–Π· Π½Π°ΠΏΠΎΠ²Π½ΡŽΠ²Π°Ρ‡Π΅ΠΌ ΠΌΠ΅Π½ΡˆΠΎΡ— Ρ‰Ρ–Π»ΡŒΠ½ΠΎΡΡ‚Ρ–.The analysis o f stiffness degradation and the identification o f damage mechanisms during and after fatigue tests of sandwich panels with PVC foam cores have been performed. The sandwich panels with cross-ply laminates skins made of glass fiber and epoxy resin were manufactured by vacuum moulding and subjected to three-point bending tests. Two PVC cores of similar type but with differing densities were investigated. The effect o f core density and thickness on the damage behavior was highlighted. Using the cyclic life criterion, fatigue curves were plotted according to two models and compared with those o f the literature. It has been demonstrated that the sandwich SD 2, with the higher core density, withstands a higher load and possesses greater rigidity in static tests, combined with an enhanced fatigue resistance when compared to sandwich SD 1 which has a lower core density

    Heat generation and transfer in automotive dry clutch engagement

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    Dynamic behaviour of automotive dry clutches depends on the frictional characteristics of the contact between the friction lining material, the flywheel, and the pressure plate during the clutch engagement process. During engagement due to high interfacial slip and relatively high contact pressures, generated friction gives rise to contact heat, which affects the material behaviour and the associated frictional characteristics. In practice excess interfacial slipping and generated heat during torque transmission can result in wear of the lining, thermal distortion of the friction disc, and reduced useful life of the clutch. This paper provides measurement of friction lining characteristics for dry clutches for new and worn state under representative operating conditions pertaining to interfacial slipping during clutch engagement, applied contact pressures, and generated temperatures. An analytical thermal partitioning network model of the clutch assembly, incorporating the flywheel, friction lining, and the pressure plate is presented, based upon the principle of conservation of energy. The results of the analysis show a higher coefficient of friction for the new lining material which reduces the extent of interfacial slipping during clutch engagement, thus reducing the frictional power loss and generated interfacial heating. The generated heat is removed less efficiently from worn lining. This might be affected by different factors observed such as the reduced lining thickness and the reduction of density of the material but mainly because of poorer thermal conductivity due to the depletion of copper particles in its microstructure as the result of wear. The study integrates frictional characteristics, microstructural composition, mechanisms of heat generation, effect of lining wear, and heat transfer in a fundamental manner, an approach not hitherto reported in literature
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