Stikla šķiedru adītais stiegrojums kompozītmateriālos

Promocijas darbs veltīts ar trikotāžas audumu stiegrotiem kompozītmateriāliem – ar polimēr- un cementmatricu. Darba ietvaros tika izgatavoti paraugi ar kulirētas (plānas) trikotāžas stiegrojumu, veikti eksperimentāli testi un datormodelēšana, izmantojot GEM ar mērķi noteikt mehāniskās īpašības šāda veida materiāliem. Pirmajā nodaļā ir veikts literatūras apskats par adīta auduma izmantošanu kompozītmateriālu stiegrošanai. Noskaidroti eksistējošie trikotāžas kompozītu stiegrojumu veidi, to modeļi un pētījumu metodes. Otrajā nodaļā ir aprakstīta paraugu izgatavošana un veikti eksperimentālie pētījumi - mikrorentgentomogrāfiskais pētījums reāla auduma struktūras noteikšanai un elastīgu īpašību eksperimentāla noteikšana ar stiepes testiem. Trešajā nodaļā ir aprakstīts teorētisks pētījums par polimerkompozītiem ar trikotāžas stiegrojumu: ir dots ģeometrijas matemātiskais apraksts un modelētas elastīgas īpašības ar galīgo elementu metodi, kā arī piedāvāta metode stiprības prognozēšanai. Ceturtajā nodaļā piedāvāts izmantot plānu trikotāžu fibrobetona stiegrošanai – ir aprakstīts paraugu izgatavošanas process un doti eksperimentāla pētījuma rezultāti, kā arī veikta betona bloku stiprības skaitliskā modelēšana. Izdarīti secinājumi par izmantoto metožu efektivitāti un ar trikotāžu stiegrotu kompozītmateriālu izmantošanas iespējas. Promocijas darba apjoms – 160 lappuses, 8 tabulas, 115 attēli un 4 pielikumi. Literatūras sarakstā ir 192 nosaukumi

Centrifūgas rotācijas analīze

51. RTU Studentu zinātniskās un tehniskās konferences materiāl

Mainīga inerces tenzora sistēmas rotācijas analīze

51. RTU Studentu zinātniskās un tehniskās konferences materiāl

Analysis of Knitted Composite Reinforcement with Variable Cross-Section Shape

Knitted fabrics have high degree of deformability and this property is attractive for use them as reinforcement in polymer composites with complex shape. Mechanical properties of composites are determined by reinforcement structure. Most theoretical models for weft knitted fabric assume that yarn cross-section is circular and constant

Ar trikotāžas audumu pastiprinātu kompozītmateriālu mehānisko īpašību pētījums

51. RTU studentu zinātniskās un tehniskās konferences materiāl

Nesimetrisku slāņainu polimēru kompozītu mehāniskā uzvedība stiepē

50. RTU studentu zinātniskās un tehniskās konferences materiāl

Experimental Investigation of Weft Knitted Fabric Layered Reinforcement Efficiency in Fiberconcrete

Reinforcing cement-based composites with continuous fibers is one of the most efficient ways to obtain high performance materials. This paper studies the application of layers of knitted textiles with relatively simple fabric architecture used to strengthen fiberconcrete beams. The objective of this study was to evaluate glass knitted fabric as reinforcement for fiberconcrete. For this purpose fiberconcrete beams with textile reinforcement in the form of three plies of glass weft knitted fabric (jersey) were produced. Four point bending test was used to experimentally investigate the influence of textile plies on composite flexural strength. The obtained results were compared with the material without textile reinforcement. The fiberconcret

Experimental Investigation of Weft Knitted Fabric Layered Reinforcement Efficiency in Fiberconcrete

Reinforcing cement-based composites with continuous fibers is one of the most efficient ways to obtain high performance materials. In this paper a layers of knitted textiles with relatively simple fabric architecture was used to strengthen fiberconcrete beams. The objective of this study was to evaluate glass knitted fabric as reinforcement for fiberconcrete. For this purpose fiberconcrete beams with textile reinforcement in a form of three plies of glass weft knitted fabric (jersey) were produced. Four point bending test was used to experimentally investigate influence of textile plies on composite flexural strength. Obtained results were compared with material without textile reinforcement. The fiberconcrete reinforced by textile layers showed better flexural performance compared to non-reinforced fiberconcrete samples

Strength of Composite Material Reinforced by 3D Knitted Fabric

Using knitted fabric as composite reinforcement is rising much interest because of its attractive mechanical properties, impact resistance, high dynamic energy absorption, and excellent stretch ability, which allows to be used in any complex shape mould without folds. Yarns curvature in the through thickness direction can be observed as the advantage for the production of 3D fabrics of complex shape

Finite Element Analysis of Weft Knitted Composites

In the present paper mechanical properties of knitted fiber reinforced polymer laminates are investigated experimentally and numerically, using unspecialized FEA. For this purpose the material unit cell was observed and its stress-strain statement was simulated using ANSYS commercial software depending on applied external loads. As example tensile properties (namely elastic modulus) in two principal directions of epoxy matrix E-glass knitted fabric laminated composites were obtained. The numerically predicted composite material mechanical parameters were compared with the experimental results and with the data obtained from previously performed analysis based on FEA software Solid Works.The numerically obtained longitudinal and transverse modulus comparison with the performed experiments has shown the ability to predict the material properties with reasonable accuracy