Računska napoved orientacije vlaken v polimernih kompozitih

Urana, Gašper (author), Halilovič, Miroslav (mentor)

Poznavanje orientacije steklenih vlaken nosi pomembno vlogo pri opisu mehanskega odziva kompozitnih izdelkov. Kljub več desetletjem raziskav še vedno ni univerzalno sprejetega modela, ki bi omogočal natančen popis orientacije vlaken. V tem delu smo izdelali program, ki omogoča izračun orientacije steklenih vlaken. Izračun temelji na modelu Folgar-Tuckerja in je primeren za obravnavo izdelkov preprostih geometrij. S pomočjo več analiz smo prikazali težave nekaterih obstoječih pristopov pri napovedovanju orientacije. Med drugim smo analizirali in prikazali vpliv gostote mreže, različnih faktorjev modelov in začetne orientacije vlaken. Izračune smo validirali s primerjavo rezultatov s komercialnim programom Moldflow. Z rezultati smo prikazali, da so za natančno določitev orientacije vlaken pomembne pravilno predpisane začetne orientacije vlaken, natančno poznavanje hitrostnega polja in pravilno nastavljeni prosti parametri.

• Language: Slovenian
• Keywords: steklena vlakna, porazdelitvena funkcija, tenzor orientacije, modeli za napovedovanje orientacije, Folgar-Tucker model, simulacija orientacije vlaken
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [G. Urana]
• Year: 2020
• Number of pages: XXI, 143 str.
• PID: 20.500.12556/RUL-119362
• UDC: 666.189.21:678:519.6(043.2)
• COBISS.SI-ID: 28713987
• Publication date in RUL: 08.09.2020

Secondary language

• Language: English
• Title: Numerical prediction of fiber orientation in polymer composites

Abstract

Knowing the orientation of glass fibers carry an important role in further optimization of composite products. Despite decades of research, there is still no universally developed model that would accurately predict fiber orientation distribution. In this work, we have made a program for determining the orientation of glass fibers. Calculation is based on the Folgar-Tucker model and can be used on simple geometries. With the help of several analyzes, we have shown the difficulties in predicting orientation. We analyzed and showed the influence of mesh density, different model factors and initial orientation of the fibers. The calculations were validated by comparing the results with commercial software Moldflow. The results show that correctly prescribed initial fiber orientations, precise knowledge of the velocity field and accurately set model factors are necessary for accurate determination of fiber orientation.

• Keywords: glass fibers, orientation distribution function, orientation tensor, fiber orientation models, Folgar-Tucker model, fiber orientation simulation