Eksperimentalna analiza i numeričko modeliranje mehaničkih svojstava hibridnih kompozita

master's thesis

• Title (english): Experimental analysis and numerical modeling of mechanical properties of hybrid composites
• Author: Lucija Lončar
• Mentor: Tatjana Haramina (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2024-03-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U sklopu rada pripravljeni su kompoziti epoksid/staklo i epoksid/lan, te tri hibridna kompozita epoksid/lan/staklo s različitim redoslijedom slaganja vlakana. Provedena su eksperimentalna ispitivanja pri rasteznom i savojnom opterećenju kako bi se utvrdilo kakav je utjecaj redoslijeda slaganja na mehanička svojstva. Dobiveni rezultati korišteni su za validaciju numeričkih modela rasteznih i savojnih ispitivanja. Provedena je numerička simulacija metodom konačnih elemenata Abaqus/Standard koristeći prikladne vrste konačnih elemenata, načine diskretizacije kompozitnih ploča i materijalnih modela. Epoksidna smola ojačana staklenim vlaknima modelirana je kao linearno elastičan ortotropan materijal, dok je epoksidna smola ojačana lanenim vlaknima modelirana kao izotropno elastičan materijal uz model plastičnosti, kako bi se bolje simuliralo ponašanje stvarnog materijala. Iz dobivenih rezultata može se zaključiti da numeričke simulacije dobro prate eksperimentalna ispitivanja te da se mogu koristiti u modeliranju različitih kombinacija rasporeda slojeva. Pretpostavka da će u usporedbi s ostalim hibridima, kompozit sa staklenim vlaknima u vanjskim slojevima pri savojnom opterećenju imati najviši modul i čvrstoću, nije se pokazala točnom, naročito u pogledu čvrstoće, dok se kompozit sa staklenim vlaknima u sredini, blizini neutralne ravnine, ponašao očekivano najlošije.

Abstract (english)

In this study, composites epoxy/glass, epoxy/ flax and three hybrid composites epoxy/flax/glass
with different stacking sequences of fiber reinforcement layers were prepared. The effect of the
fiber stacking sequence on mechanical properties was tested under tensile and flexural load.
The obtained results were used to validate numerical models of tensile and bending tests.
Numerical simulations were performed using the finite element method Abaqus/Standard, using
appropriate types of finite elements, discretization methods of composite plates, and material
models. The epoxy resin reinforced with glass fibers was modeled as a linear elastic orthotropic
material, while the epoxy resin reinforced with flax fibers was modeled as an isotropic elastic
material with a plasticity model to better simulate the behavior of the real material. From the
obtained results, it can be concluded that numerical simulations follow experimental tests well
and can be used to model different combinations of fiber stacking orientations. The assumption
that the hybrid composite with glass fibers in the outer layers will be superior to other hybrids
under flexural load has not been proven to be correct, whereas the one with glass fibers next to
the middle neutral plane was the weakest as expected.

• Keywords: hibridni kompoziti; lanena vlakna; MKE; savojno ispitivanje; rastezno ispitivanje
• Keywords (english): hybrid composites; flax fibers; FEM; bending test; tensile test
• Language: croatian
• URN:NBN: urn:nbn:hr:235:183461
• 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: 2024-03-26 06:37:17