Primjena nenewtonskih tekućina u izradi polimernih kompozita

master's thesis

• Title (english): Application of non-Newtonian fluids in the production of polymer composites
• Author: Luka Ivanković
• Mentor: Zdravko Schauperl (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2024-05-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Tekućine kod kojih viskoznost (pri konstantnoj temperaturi) ovisi o uvjetima tečenja (brzini
smicanja, smičnom naprezanju) nazivaju se nenewtonske tekućine. Kad se viskoznost
tekućine povećava s povećanjem smične brzine govori se o posmičnom
zgušnjavanju/zadebljanju. Posmično zgušnjavajuća tekućina (engl. Shear-thickening fluid,
STF) se pod primijenjenim naprezanjem, zbog povećanja viskoznosti, ponaša kao čvrsti
materijali, a kada se opterećenje ukloni iz medija, STF prelazi u početno tekuće stanje. To
jedinstveno svojstvo pobudilo je veliku pozornost znanstvenika fokusiranih na razvoj
pametnih materijala i struktura za zaštitne primjene.
U ovom radu dan je prikaz dosadašnjih istraživanja polimernih kompozitnih materijala
ojačanih tkaninama impregniranim s nenewtonskim (STF) tekućinama, te objašnjeni
mehanizmi zaštite od kinetičkih penetratora.
Nadalje, istraživan je utjecaj impregnacije različitih tkanina (načinjenih od staklenih,
aramidnih, bazaltnih i UHMWPE vlakana) nenewtonskom tekućinom koja pokazuje
posmično zgušnjavanje (na temelju silicijevog dioksida i polietilen glikola) na svojstva
epoksidnih kompozitnih materijala. Mehanička svojstva uzoraka procijenjena su pomoću
vlačnog pokusa i ispitivanja udarnog rada loma.

Abstract (english)

Liquids whose viscosity (at constant temperature) depends on the flow conditions (shear rate,
shear stress) are called non-Newtonian liquids. If the viscosity of the liquid increases with
increasing shear rate, it is called a shear-thickening fluid. Shear-thickening fluid (STF)
behaves like solid materials under applied stress due to the increase in viscosity, and when the
load is removed from the medium, STF changes to the initial liquid state. This unique
property has attracted a lot of attention from scientists focused on the development of smart
materials and structures for protective applications.
In this paper, an overview of the current research on polymer composite materials reinforced
with fabrics impregnated with non-Newtonian (STF) fluids is given, and the mechanisms of
protection against kinetic penetrators are explained.
Furthermore, the influence of impregnation of different fabrics (made of glass, aramid, basalt
and UHMWPE fibers) with a non-Newtonian liquid showing shear thickening (based on silica
and polyethylene glycol) on the properties of epoxy composite materials was investigated.
The mechanical properties of the samples were evaluated using a tensile test and an impact
fracture test

• Keywords: nenewtonska tekućina; silicijev dioksid; polietilen glikol; ojačala; staklena vlakna; aramidna vlakna; bazaltna vlakna; UHMWPE vlakna; epoksidna smola; polimerni kompozit; mehanička svojstva
• Keywords (english): non-Newtonian fluid; silicon dioxide; polyethylene glycol; reinforced; glass fibers; aramid fibers; basalt fibers; UHMWPE fibers; epoxy resin; polymer composite; mechanical properties
• Language: croatian
• URN:NBN: urn:nbn:hr:235:255739
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-05-09 14:39:52