Mehanička karakterizacija 3D ispisanih polimernih materijala

master's thesis

• Title (english): Mechanical characterization of 3D printed polymer materials
• Author: Bartol Filić
• Mentor: Lana Virag (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2024-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Brzim napretkom tehnologija 3D ispisa znatno je ubrzan proces razvoja proizvoda, naročito izrada prototipa. Uz brze prototipe i mogućnost obrade konstrukcija FEM analizom optimizacija konstrukcija poprima novu dimenziju smanjenja troškova izrade i potrebe za predimenzioniranjem. Kako bi se konstrukcije pravilno dimenzionirale za potrebnu svrhu bitno je precizno i detaljno poznavati svojstva korištenih materijala jer se na tome zasniva cijeli proces konstruiranja. Od mehaničke karakterizacije materijala na nižoj razini, odnosno iz jednoosnog vlačnog pokusa, postavljaju se materijalni modeli koji će bolje opisivati svojstava i pri složenijim slučajevima opterećenja.
Ispisom uzoraka za vlačno ispitivanje na PolyJet pisaču znatno boljih performansi od široko dostupnih FDM tipova pisača dovodi se u pitanje anizotropnost materijala s obzirom da su pojedini slojevi ispisa znatno manji, precizniji i polimerizirani uz pomoć fotopolimerizacije. Iz tog se razlog ispituju uzorci dvaju smjerova ispisa, longitudinalnog i transverzalnog pri različitim brzinama ispitivanja.
Očitavanjem podataka uočavaju se potencijalne ovisnosti mehaničkih svojstava o uvjetima ispitivanja i izrade uzoraka, a potom se karakteriziraju, eng. fitting, koristeći programski kod, odnosno prilagođavaju se eksperimentalnim podatcima materijalnih modela i određivanje pripadnih parametara. Takvo prilagođavanje dati će vrijednosti materijalnih konstanti koje se dalje mogu koristiti za računanje naprezanja u drugim slučajevima opterećenja.

Abstract (english)

The rapid progress of 3D printing technology has significantly accelerated the product
development process, especially prototyping. With the ability of making prototypes much faster
and the possibility of processing structures using FEM analysis, the optimization of structures
greatly decreases production costs and the need for overbuilding parts. In order to properly
design constructions for the required purpose, it is essential to know precisely and in detail the
properties of the materials used. The entire construction process is based on this. From the
mechanical characterization of the materials as a base knowledge, for example from the uniaxial
tensile test, material models are established and will better describe the properties even in more
complex load cases.
Printing samples for tensile testing on a PolyJet printer with significantly better performance
than the widely available FDM types of printers questions the anisotropy phenomenon of the
material, given that individual print layers are significantly smaller, more precise and
polymerized by photopolymerization. For this reason samples were printed in two directions,
longitudinal and transverse, in comparison to the axis of tensile testing and are tested at different
test speeds.
By reading the data, the potential dependence of the mechanical properties on the testing and
production conditions are observed, and then they are characterized using a program code that
performs fitting, the adaptation of the experimental data to the material models. Such an
adjustment will provide values of material constants that can further be used to calculate loads
in other load cases.

• Keywords: PolyJet; 3D ispisivanje; anizotropnost; brzina ispitivanja; jednoosni vlačni test; materijalna karakterizacija
• Keywords (english): PolyJet; 3D printing; anisotropy; testing speed; uniaxial tensile test; fitting
• Language: croatian
• URN:NBN: urn:nbn:hr:235:007660
• 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: 2024-07-15 12:39:52