Numerička simulacija dvoosnog vlačnog eksperimenta 3D ispisanih polimernih materijala

undergraduate thesis

• Title (english): Numerical simulation of the biaxial tension experiment for 3D printed polymers
• Author: Ana Tomljanović
• Mentor: Igor Karšaj (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2020-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Aditivna proizvodnja je proizvodni proces je koji se počeo razvijati 1980-ih godina, a u sve široj je primjeni zadnjih nekoliko godina. Primjenom procesa aditivne proizvodnje moguće je izraditi modele komplicirane geometrije. Također, primjenom različitih materijala moguće je dobiti konačne proizvode odgovarajućih mehaničkih svojstava. Upravo to su razlozi sve češće primjene 3D ispisa u biomedicinskoj industriji. Budući da se radi o relativno novoj tehnologiji, pri procesu 3D ispisa koriste se i novi materijali čija je svojstva potrebno ispitati. Eksperiment koji se najčešće provodi za ispitivanje mehaničkih svojstava materijala je statički vlačni eksperiment kojim se utvrđuju osnovna mehanička svojstva poput granice razvlačenja, vlačne čvrstoće i modula elastičnosti. Dvoosnim vlačnim testom može se ispitati kompleksnije ponašanje materijala pri složenom stanju naprezanja. Pri provedbi dvoosnog vlačnog eksperimenta na križnom uzorku dolazi do preranog pucanja uzorka zbog njegove geometrije. Kako bi se u homogenom dijelu uzorka postigla željena deformacija potrebno je optimirati uzorak na kojem se vrši ispitivanje. U ovom radu prikazane su različite geometrije križnog uzorka i njihov utjecaj na rezultate eksperimenta. Odabran je uzorak s kojim su dobiveni najbolji rezultati te je detaljno razrađen. Za izradu CAD modela korišten je programski paket Catia V5R21 dok su numeričke analize provedene u programskom paketu Abaqus.

Abstract (english)

Additive manufacturing is a production process which started developing in 1980s but became more popular and common in the last decade. Using computer aided design (CAD) or 3D object scanners, additive manufacturing allows for the creation of objects with precise geometric shapes. Also, by using different materials it is possible to achieve wanted mechanical properties. These are some of the reasons why 3D printing is being used in biomedical engineering.
Since 3D printing is relatively new technology, new materials are being used so it's necessary to identify their properties. Most used experiment for identifying material properties is the uniaxial tensile test. Some of the properties that are measured and determined via a tensile test are ultimate tensile strength, breaking strength and Young's modulus.
Planar biaxial tensile tests determine the mechanical properties of the test sample that experiences tensile biaxial states of stress and its test data is superior to uniaxial data if the material experiences stress in complex multiaxial configurations. While examining the cruciform sample a stress concentration occurs in specific area and the specimen does not deform to a desired level when it has fractured in other areas. The main goal in this final paper was to increase the stretch ratio in homogenous part of the specimen so new, optimized specimen must have been designed. Different geometries of the cruciform specimen and their impact on the results are shown in this final paper.
Catia V5R21 software was used to create the CAD model, while numerical analyzes were performed in the Abaqus software package.

• Keywords: aditivna proizvodnja; metoda konačnih elemenata; dvoosni vlačni eksperiment; hiperelastičnost
• Keywords (english): additive manufacturing; finite element method; biaxial tensile test; hyperelasticity
• Language: croatian
• URN:NBN: urn:nbn:hr:235:424543
• 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: 2020-09-22 12:35:38