The effect of topology and volume fraction on integrity of 3D printed cellular components under bending loading

master's thesis

• Title (croatian): Utjecaj topologije i volumenskog udjela na integritet 3D tiskanih komponenti opterećenih na savijanje
• Author: Iva Rački
• Mentor: Željko Božić (mentor)
• Mentor: Katarina Monkova https://orcid.org/0000-0002-5153-346X (komentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2024-05-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

An introduction to Additive Manufacturing (AM) technologies with a focus on 3D metal printing was given, and a short overview of the theory related to cellular porous structures, in particular, to Triply Periodic Minimal Surface (TPMS) structures was presented. Porous materials offer not only direct benefits such as lighter construction, material savings, and improved physical properties but also indirect advantages stemming from their widespread application in industries like aerospace and automotive, leading to fuel savings and environment protection. In this thesis the effect of specific weight and the type of cellular porous structure on the failure behaviour of a beam specimen subjected to bending was investigated. Three distinct structures (Schoen IWP, Fischer-Koch S, and Schoen F-RD), with five different specific weights, made from AlSi10Mg aluminium alloy using Direct Laser Metal Sintering (DMLS) technology were examined. A three-point bending test was conducted at room temperature using a Zwick/Roell 1456 universal testing machine to assess sample failure.
The bending forces with respect to specimens’ deflection were recorded, and energy absorption and ductility indices were computed in order to investigate the effects of the three different porous structures and their specific weight on the bending strength of the considered specimens. It was observed from the experimental results that specimens with lower specific weight can bear relatively higher load compared to specimens with higher specific weight. Furthermore, in fractured specimens crack extension was influenced by the type of structure, suggesting that future control of crack propagation could be achieved through geometrical arrangements of pores.

Abstract (croatian)

Dan je uvod u tehnologije aditivne proizvodnje (AM) s fokusom na 3D ispis metala, te je dan kratak pregled teorije vezane uz stanične porozne strukture, posebice strukture trostruko periodične minimalne površine (TPMS). Porozni materijali nude ne samo izravne prednosti kao što su lakša konstrukcija, ušteda materijala i poboljšana fizička svojstva, već i neizravne prednosti koje proizlaze iz njihove široke primjene u industrijama poput zrakoplovne i automobilske, što dovodi do uštede goriva i zaštite okoliša. U ovom diplomskom radu istražen je utjecaj specifične težine i vrste stanične porozne strukture na ponašanje pri slomu savijanja uzorka grede. Ispitane su tri različite strukture (Schoen IWP, Fischer-Koch S i Schoen F-RD), s pet različitih specifičnih težina, izrađene od AlSi10Mg aluminijske legure korištenjem tehnologije izravnog laserskog sinteriranja metala (DMLS). Ispitivanje savijanjem u tri točke provedeno je na sobnoj temperaturi korištenjem Zwick/Roell 1456 univerzalnog ispitnog stroja za procjenu kvara uzorka.
Zabilježene su sile savijanja s obzirom na otklon uzoraka, a izračunati su indeksi apsorpcije energije i duktilnosti kako bi se istražili učinci triju različitih poroznih struktura i njihove specifične težine na čvrstoću savijanja razmatranih uzoraka. Iz rezultata pokusa uočeno je da uzorci manje specifične težine mogu podnijeti relativno veće opterećenje u odnosu na uzorke veće specifične težine. Nadalje, u slomljenim uzorcima na širenje pukotine utjecao je tip strukture, što sugerira da bi se buduća kontrola širenja pukotine mogla postići pomoću geometrijskog rasporeda pora.

• Keywords: Additive manufacturing; 3D metal printing; porous structures; Triply Periodic Minimal Surface; technology; bending; failure; crack
• Keywords (croatian): Aditivna proizvodnja; 3D ispis metala; porozne strukture; Trostruko periodična minimalna površina; tehnologija; savijanje; kvar; pukotina
• Language: english
• URN:NBN: urn:nbn:hr:235:404508
• 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: Embargoed access; Embargo expiration date: 2029-05-16
• Created on: 2024-05-13 10:53:43