Numerički model eksperimentalnog ispitivanja 3D ispisanih dvokomponentnih arterijskih replika

master's thesis

• Title (english): Numerical model of multi-material 3D printed arterial replicas experimental testing
• Author: Antonio Jurić
• Mentor: Igor Karšaj (mentor)
• Mentor: Lana Virag (komentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2021-01-22, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

U radu je prikazana prilagodba numeričkog postupka modeliranja pokusa istezanje – tlak za arterijske replike izrađene aditivnom tehnologijom. Arterijske replike koncipirane su na temelju histološke analize arterijske stijenke provedene u poglavlju 2, gdje su opisani osnovni konstituenti te njihov utjecaj na cjelokupno mehaničko ponašanje. Takva kompleksna građa arterije, koja ima izrazito nelinearno mehaničko ponašanje, replicirana je istovremenim korištenjem dva materijala, što omogućuje PolyJet tehnologija 3D ispisa, opisana u poglavlju 5. U konačnici je mehaničko ponašanje takvih replika ispitano pokusom istezanje – tlak jer izvrsno oponaša in vivo multiaksijalne uvjete opterećenja arterije, prema poglavlju 3.

Cilj rada je bio ispitati utjecaj svakog značajnijeg faktora koji može utjecati na numeričke rezultate. To u prvom redu podrazumijeva utjecaj izbora materijalnog modela te pripadajućih materijalnih parametara 3D ispisanih materijala. Budući da se koristi teorija hiperelastičnosti, prikazan je kratki pregled izabranih materijalnih modela (neo-Hooke i Mooney-Rivlin) u poglavlju 6. No, kako takve modele nije moguće opisati klasičnom teorijom elastičnosti, prvotno je objašnjena mehanička pozadina takvih materijala preko mehanike kontinuuma. Osim navedenog faktora ispitani su i utjecaji dodjeljivanje pojedinog rubnog uvjeta te modeliranje veze između ispisanih materijala, detaljnije predstavljeni u poglavlju 8. S točno definiranim numeričkim postupkom bilo bi moguće predvidjeti mehaničko ponašanje drugih geometrija arterijske replike s različitim kombinacijama osnovnih materijala. Na taj način bi se značajno smanjio broj potrebnih eksperimenata te potrošnja materijala. Stoga je evaluacijom učinaka izmjena određenih faktora izabran optimalni numerički opis eksperimenta, naznačen u poglavlju 9 i 10.

Abstract (english)

This thesis presents the adaptation of the numerical procedure of modeling the extension – inflation experiment for arterial replicas fabricated by additive technology. Arterial replicas were designed based on histological analysis of the arterial wall clarified in Chapter 2, where the basic constituents and their influence on the overall mechanical behavior are described. Such a complex artery structure with highly nonlinear mechanical behavior was replicated by simultaneously printing two materials enabled by PolyJet 3D additive technology presented in Chapter 5. Ultimately, the mechanical behavior of such replicas was tested by the extension – inflation experiment because it perfectly mimics the in vivo multiaxial artery loading conditions, according to Chapter 3.

The aim of this work was to take into account any significant factor that may affect the numerical results. This primarily implies the influence of the choice of material model and the associated material parameters of 3D printed materials. Since the theory of hyperelasticity is used, a brief overview of selected material models (neo-Hooke and Mooney-Rivlin) is presented in Chapter 6. However, as such models cannot be described by the theory of elasticity, the mechanical background of such materials was initially explained through continuum mechanics. In addition to the above mentioned factor, the influences of assigning an individual boundary condition and modeling the relationship between printed materials were examined, presented in more detail in Chapter 8. With a precisely defined numerical procedure, it would be possible to predict the mechanical behavior of other arterial replica geometries with different combinations of base materials. This would significantly reduce the number of required experiments and material consumption. Therefore, by evaluating the effects of changes of certain factors, the optimal numerical description of the experiment, indicated in Chapter 9 and 10, was chosen.

• Keywords: arterijska stijenka; hiperelastičnost; numeričko modeliranje; metoda konačnih elemenata; neo-Hooke; Mooney-Rivlin
• Keywords (english): arterial wall; hyperelasticity; numerical modelling; finite element method; neo-Hooke; Mooney-Rivlin
• Language: croatian
• URN:NBN: urn:nbn:hr:235:531556
• 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: 2021-01-18 12:36:13