Analiza utrujanja kiralnih avksetičnih struktur iz aluminijeve zlitine aa 5083-h111

magistrsko delo

Patrik Lampret (Author), Srečko Glodež (Mentor), Branko Nečemer (Co-mentor)

Abstract

V magistrski nalogi je predstavljena analiza utrujanja kiralnih avksetičnih struktur iz aluminijeve zlitine AA 5083-H111. Na začetku so obravnavane teoretične osnove celičnih struktur, kjer so predstavljene lastnosti celičnih materialov in izhodišča geometrijskih veličin, s katerimi so bile strukture narejene. Sledijo teoretične osnove utrujanja materialov, kjer so opisane in predstavljene metode dimenzioniranja na življenjsko dobo skupaj z mehanizmi utrujanja. V nadaljevanju so obravnavane numerične simulacije, ki so obsegale konvergenčno analizo, določevanje ustreznega števila osnovnih celic ter ugotavljanje poteka utrujanja posameznih kiralnih avksetičnih struktur. Za namene konvergenčne analize je bil definiran numerični model, ki je obsegal predpis materialnega modela, vpetja, obremenitev ter mreže končnih elementov. Na podlagi deformacij, ki so bile posledica obremenitev v obliki pomikov, je bila narejena konvergenčna analiza, s katero je bila določena globalna velikost končnih elementov. Za določanje ustreznega števila osnovnih celic je bil analiziran odziv kiralnih avksetičnih struktur pri različnih razporeditvah osnovnih celic. Raziskan je bil vpliv Poissonovega količnika na potek obremenjevanja, kjer je bilo ugotovljeno, pri katerih strukturah se pojavi avksetični učinek in kako intenziven je. Na koncu je bila s pomočjo deformacijske metode ugotovljena življenjska doba kiralnih avksetičnih struktur. Določanje življenjske dobe je bilo grafično ovrednoteno s pomočjo amplitudnih deformacij, amplitudnih sil in povprečne deformacijske energije na cikel. Numerični rezultati so bili opisani in predstavljeni v skladu z vnaprej določenimi načini, od koder je bilo ugotovljeno, katera kiralna struktura pri predpisani obremenitvi zdrži največ obremenitvenih ciklov in katera struktura pokaže najbolj ugodno kombinacijo mehanskih in fizikalnih lastnosti.

Keywords

malociklično utrujanje;numerične simulacije;kiralne avksetične strukture;aluminijeve zlitine;magistrske naloge;

Data

Language:	Slovenian
Year of publishing:	2023
Typology:	2.09 - Master's Thesis
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	[P. Lampret]
UDC:	621.7.072-11:678.4.027(043.2)
COBISS:	170948099
Views:	129
Downloads:	19
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Fatigue analysis of chiral auxetic structures made of aluminium alloy aa 5083-h111
Secondary abstract:	The master thesis presents a fatigue analysis of chiral auxetic structures made of aluminium alloy AA 5083-H111. The theoretical background of cellular structures is discussed at the beginning, where the properties of the cellular materials and the starting geometrical parameters, with which the structures were made, are presented. This is followed by the theoretical basis of material fatigue, where fatigue analysis methods are described and presented together with the mechanisms of material fatigue. Numerical simulations are then discussed, comprising convergence analysis, determination of the appropriate number of repeating unit cells and determination of the fatigue behaviour of individual chiral auxetic structures. For the purpose of the convergence analysis, a numerical model was defined, including the prescription of the material model, clamping, loading and the finite element mesh. Based on the deformations, resulting from the displacement loads, a convergence analysis was performed to determine the global finite element size. The response of the chiral auxetic structures was analysed at different repeating unit cell arrangements to determine the appropriate number of repeating unit cells. The influence of the Poisson's ratio on the loading process was investigated to determine which structures exhibit the auxetic effect and how intense it is. Finally, the lifetime of the chiral auxetic structures was determined using the deformation method. The lifetime determination was evaluated on the approach of amplitude strains, amplitude forces and average dissipated energy per cycle. The numerical results were described and presented according to predefined approaches, from which it was determined which chiral structure can withstand the highest number of loading cycles at the prescribed load and which structure shows the most favourable combination of mechanical and physical properties.
Secondary keywords:	low cycle fatigue;numerical simulations;chiral auxetic structures;aluminium alloys;
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za strojništvo, Konstrukterstvo
Pages:	1 spletni vir (1 datoteka PDF (XV, 64 f.))
ID:	19930885