Izbor materijala za okvir invalidskih kolica

master's thesis

• Title (english): Material selection for the wheelchair frame
• Author: Ana Marija Kolar
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-03-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Cilj ovog diplomskog rada bio je izabrati optimalan materijal za okvir invalidskih kolica. Na samom početku rada opisana je funkcija invalidskih kolica. Prema izabranoj grupi korisnika dobivene su potrebe odnosno zahtjevi na okvir invalidskih kolica. Analizom zahtjeva izdvojeni su konstrukcijski zahtjevi pomoću kojih je napravljen model invalidskih kolica. Na modelu je proveden proračun na najkritičnijem mjestu okvira invalidskih kolica. Prema rezultatima proračuna napravljen je predizbor materijala kako bi se suzilo područje izbora optimalnog materijala.
Zahtjevi na okvir invalidskih kolica, dobiveni od korisnika, preslikani su u svojstva materijala. Digitalno-logičkom metodom izračunat je faktor važnosti za svako svojstvo. Metodom utjecajnosti svojstava izabran je polimerni kompozit s ugljičnim vlaknima kao optimalan materijal za okvir invalidskih kolica. Bez obzira na rezultate dobivene provedenim metodama, zbog visoke cijene kompozitnog materijala, kao materijal okvira invalidskih kolica za ciljanu dobnu skupinu izabrana je aluminijska legura. Aluminijske legure pokazale su se kao materijal koji pruža balans između kvalitete i cijene što su bili najbitniji traženi faktori kod razmatranja.
Kako bi se potvrdilo da izabrani materijal i napravljeni model za ciljanu grupnu skupinu može izdržati zadano opterećenje, provedena je numerička analiza. Utvrđeno je da dobiveno maksimalno naprezanje ne prelazi vrijednost dopuštenog naprezanja, s dovoljnom sigurnošću.

Abstract (english)

The aim of this master's thesis was to choose the optimal material for the wheelchair frame. In the introductory part of the work, the function of the wheelchair is described. According to the selected group of users, the needs and requirements for the wheelchair frame were obtained. The requirements analysis identified the structural requirements that were used to create the wheelchair model. On the most critical point of the wheelchair was made an analytical calculation. According to the calculation results, a pre-selection of materials was made to narrow down the area of the optimal material selection.
The requirements on the wheelchair frame, obtained from the user, are mapped to the material properties. The factor of importance for each property was calculated using the digital-logic method. Polymer composite with carbon fibers was chosen as the optimal material for the wheelchair frame using the method of properties influence. Regardless of the results obtained by the implemented methods, due to the high cost of the composite material, aluminum alloy was chosen as the wheelchair frame material for the selected age group. Aluminum alloys proved to be a material that provides a balance between quality and price, which were the most important required factors when considering.
To confirm that the selected material and the model made for the target group can withstand the given load, a numerical analysis was carried out. It was determined that the obtained maximum stress does not exceed the value of the permissible stress, with sufficient safety.

• Keywords: izbor materijala; okvir invalidskih kolica; numerička analiza
• Keywords (english): material selection; wheelchair frame; numerical analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:235:655315
• 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: 2023-03-23 11:41:27