DEFORMACIJE TKANINA UVJETOVANE ANIZOTROPNOŠĆU

doctoral thesis

• Title (english): WOVEN FABRIC DEFORMATION AS A FUNCTION OF ANISOTROPY
• Author: Snježana Brnada
• Mentor: Stana Kovačević (mentor)
• Committee member: Zlatko Vrljičak (predsjednik povjerenstva)
• Committee member: Željko Šomođi (član povjerenstva)
• Committee member: Polona Dobnik Dubrovski (član povjerenstva); strani drzavljanin: Nije dostupno
• Granter: University of Zagreb; Faculty of Textile Technology; (Department of Projecting and Management of Textiles); Zagreb
• Defense date and country: 2017, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Textile Technology; Textile-Mechanical Engineering
• Universal decimal classification (UDC): 677 - Textile industry

Abstract

U ovom doktorskom radu definirani su parametri tkanina različitih konstrukcijskih karakteristika koji utječu na njihovu anizotropnost. Na različitim uzorcima tkanina istražena je anizotropnost njihovih mehaničkih svojstava kao rezultat sinergije prethodno definiranih strukturnih karakteristika te mogućnost predikcije smjera i količine deformacije nastale kao posljedice različitih količina i smjerova naprezanja u tkanini. Definirani prediktori anizotropije praktično su potvrđeni usporedbom rezultata analize s teorijskim materijalnim modelom. Cilj ovog rada je i istraživanje naprezanja pri vlačnom istezanju, Poissonova omjera, modula elastičnosti i smičnog modula na različitim vrstama tkanina. Vrijednosti ovih veličina odredile su se empirijski, standardnim i nestandardnim metodama. Ova istraživanja provela su se na inovativnom, novo razvijenom uređaju koji je dogradni dio dinamometra za mjerenje prekidnih sila plošnih materijala. Time su istražene bočne sile tkanina za vrijeme vlačnog naprezanja. Istražen je utjecaj anizotropije na deformabilnost tkanina u različitim smjerovima i područjima naprezanja (cijela krivulja naprezanja) do samog prekida. Na temelju toga, rezultati ovog istraživanja daju nove spoznaje o ponašanju tkanina prilikom vlačnog i smičnog naprezanja pri (Poissonov omjer, modul elastičnosti, modul smičnosti) čime je dan određeni doprinos dosadašnjim znanstvenim istraživanjima. U ovoj doktorskoj disertaciji istražena su anizotropna svojstva tkanina pri čemu je utvrđena neortotropna karakteristika dijagonalno strukturiranih tkanina. Utvrđen je utjecaj napetosti i utkanja osnove i potke na deformacijska svojstva tkanine. Izrađen je mehanički model za opis vlačnog testa s bočnom restrikcijom te utvrđen Poissonov omjer, Youngov modul elastičnosti i smični modul po čitavom rasponu krivulje naprezanja.

Abstract (english)

In this thesis dissertation, the parameters of the fabric of different structural characteristics that affect their anisotropy are defined. The anisotropy of mechanical properties was investigated on different fabric samples as a result of the synergy of previously defined structural characteristics and the possibility of predicting the direction and amount of deformation caused by different amounts and strain directions in the fabric. Defined predictors of anisotropy are confirmed by comparing the results of the analysis with the theoretical material model. The aim of this thesis is to investigate the stresses in terms of tensile stretching, Poisson ratio, elastic modulus and shear module on different types of fabric. The values were determined by empirical, standard and non-standard methods. The research has been carried out on an innovative, newly developed device that is an integral part of the dynamometer for measuring the breaking forces of the flat material. Thus, the lateral forces of the fabric were investigated during tensile stress. The influence of anisotropy on fabric deformability in different directions and areas of stress (full stress curve) was investigated until the break. Based on this, the results of this research provided new insights on the behavior of the fabric during tensile and shear stress (Poisson's ratio, modulus of elasticity, shear module), thus giving a certain contribution to previous scientific research. In this doctoral dissertation, anisotropic properties of the fabric were investigated and the deviation of orthotropic behaviour of diagonal structured fabrics was defined. The influence of the tension and crimp on the deformation properties of the fabric was determined. A mechanical model for the description of the tensile test with the side restriction was established and the Poisson ratio, the Youngov modul of elasticity and the shear module were determined throughout the range of stress curves.

• Keywords: Tkanine; anizotropija; mehanika tekstila; deformacije; dijagonalno strukturirane tkanine; Poissonov omjer; modul elastičnosti; kutna deformacija; smični modul
• Keywords (english): Woven fabrics; anisotropy; textile mechanics; deformation; diagonally structured fabrics; Poisson's ratio; elastic modulus; angular deformation; shear module
• Language: croatian
• URN:NBN: urn:nbn:hr:201:390376
• Study programme: Title: Textile Science and Technology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti, polje tekstilna tehnologija (doktor/doktorica znanosti, područje tehničkih znanosti, polje tekstilna tehnologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2021-04-23 12:02:00