Mehanička karakterizacija 3D ispisanog PLA polimera

undergraduate thesis

• Title (english): Mechanical characterization of 3D printed PLA polymer
• Author: Fran Šklebar
• Mentor: Lana Virag (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2025-02-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Sve lakšim pristupom i češćom upotrebom tehnologije 3D ispisa u procesu razvoja proizvoda,
te izrade prototipa dolazi do smanjenja troškova, ubrzavanja razvoja i testiranja proizvoda.
Kako bi se konstrukcije mogle pravilno dimenzionirati, potrebno je precizno i detaljno
poznavanje svojstava materijala koji se koriste. Mehaničkom karakterizacijom materijala,
koristeći jednoosni vlačni test, moći će se postaviti materijalni modeli koji će bolje opisivati
svojstva i pri složenim slučajevima opterećenja.
Uzorci za vlačno ispitivanje polilaktida ispisani su FDM tipom pisača, široko dostupnog u
industriji i kućnoj primjeni. Mogućnosti promjene raznih parametara ispisa, ispitivanja i
geometrije mogu uvelike utjecati na svojstva koja će materijal nakon ispisa posjedovati. Iz tog
se razloga ispituju uzorci pri dva smjera ispisa, uzdužnog i poprečnog sa različitim debljinama
epruveta, različitim visinama sloja pri različitim brzinama ispitivanja. Koristi se optimizirani
oblik epruvete naspram normiranog, zbog njenog problematičnog oblika koji FEM analizom i
eksperimentalnim ispitivanjem puca izvan ispitnog, homogenog područja.
Nakon obavljenih vlačnih ispitivanja, izvršena je materijalna karakterizacija za svaku
kombinaciju spomenutih parametara koristeći metodu najmanjih kvadrata. Podaci su
uspoređeni s literaturom u kojoj su korištene epruvete po normi, kao i s podacima proizvođača.
Dobivene materijalne konstante mogu se dalje koristiti za računanje naprezanja u različitim
slučajevima opterećenja.

Abstract (english)

With easier access to and more frequent use of 3D printing technology in product development
and prototype manufacturing, there is a reduction in costs and an acceleration of product
development and testing. In order for constructions to be properly dimensioned, precise and
detailed knowledge of the properties of the materials used is necessary. Through mechanical
characterization of the materials, using a uniaxial tensile test, material models can be
established that will better describe their properties even in complex loading scenarios.
Samples for tensile testing of polylactic acid were printed using an FDM-type printer, which is
widely available in both industry and home use. The ability to change various printing
parameters, testing conditions and geometry can significantly affect the properties that the
material will have after printing. For this reason, the samples are tested in two printing
directions, longitudinal and transverse, with different tube thicknesses, different layer heights
and different testing speeds. An optimized tube shape is used instead of the standardized one,
due to its problematic shape, which, through FEM analysis and experimental testing, breaks
outside the test's homogeneous area.
After conducting tensile tests, material characterization was performed for each combination of
the mentioned parameters using the least squares method. The data were compared with
literature where standardized tubes were used, as well as with manufacturer data. The obtained
material constants can be further used to calculate stresses in different loading scenarios.

• Keywords: FDM; 3D ispis; jednoosni vlačni test; materijalna karakterizacija
• Keywords (english): FDM; 3D printing; uniaxial tensile test; mechanical characterization
• Language: croatian
• URN:NBN: urn:nbn:hr:235:032896
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-02-21 12:21:28