Usporedba numeričkog i analitičkog proračuna zareznog djelovanja kod vratila

undergraduate thesis

• Title (english): Comparison of numerical and analytical calculation of notch action in shafts
• Author: Andrija Butković
• Mentor: Ivica Skozrit (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; (Department of Engineering Mechanics); (Chair of Mechanics and Strength of Materials); Zagreb
• Defense date and country: 2024-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Vratila su jedan od neizostavnih strojnih elemenata u velikom broju industrija, strojeva i uređaja. Zbog konstrukcijskih razloga često su izrađena s promjenjivim promjerom s obzirom na uzdužnu os vratila. Prilikom opterećenja vratila, na mjestima promjene promjera, dolazi do koncentracije naprezanja. Koncentracije naprezanja na vratilu u ovom su radu određena analitičkim proračunom. Analitički koncentracije naprezanja računaju se pomoću nominalnog naprezanja presjeka i faktora zareznog djelovanja. Naprezanja izazvana faktorom zareznog djelovanja moraju ispunjavati uvjete sigurnosti pri konstrukciji vratila. Uz analitički proračun, provedena je numerička analiza vratila te su rezultati uspoređeni.
Prvi dio rada sadrži teorijski prikaz vezan uz vratila i metodu konačnih elemenata. Opisane su vrste i izvedbe vratila. Također su prikazani i opisani neki od strojnih elemenata koji se mogu nalaziti na vratilima. Teorijski osvrt na metodu konačnih elemenata objašnjava njezino korištenje te prikazuje konačne elemente za 3D analizu.
Nakon teorijskog dijela, proveden je analitički proračun vratila. Kroz proračun je određeno opterećenje na vratilu nakon definiranja parametara zadatka. Vratilo je dimenzionirano s obzirom na opterećenje, zatim je provjerena dinamička sigurnost vratila uzevši u obzir utjecaje faktora zareznog djelovanja kod kritičnih presjeka vratila.
U trećem dijelu rada prikazan je numerički proračun vratila i verifikacijskih modela. Konačan oblik vratila modeliran je u programu Solidworks 2020® te je pomoću njega provedena numerička analiza u programskom paketu Abaqus®. Dobiveni rezultati analitičkog i numeričkog proračuna vratila međusobno su uspoređeni.

Abstract (english)

Shafts are one of the essential machine elements in a wide range of industries, machinery, and devices. Due to design considerations, they are often manufactured with variable diameters along the longitudinal axis of the shaft. When subjected to loads, stress concentration occurs at points where the diameter changes. In this study, stress concentrations on the shaft are presented using an analytical method. Analytical methods calculate stress concentrations based on the nominal stress of the cross-section and the notch effect factor. Stresses induced by the notch effect factor must meet safety requirements during shaft design. In addition to the analytical calculations, a numerical analysis of the shaft was performed, and the results were compared.
The first part of the paper provides a theoretical overview related to shafts and the finite element method. Different types and designs of shafts are described. Additionally, several machine elements that can be found on shafts are presented and described. The theoretical review of the finite element method explains its use and demonstrates finite elements for 3D analysis.
Following the theoretical part, an analytical calculation of the shaft was conducted. Through the calculation, the load on the shaft was determined after defining the task parameters. The shaft was dimensioned according to the load. Then, the dynamic safety of the shaft was verified, taking into account the effects of the notch factor at critical cross-sections of the shaft.
In the third part of the paper, a numerical calculation of the shaft and verification models is presented. The final shape of the shaft was modeled in Solidworks 2020® and a numerical analysis was conducted using the Abaqus® software package. The results of the analytical and numerical calculations of the shaft were compared.

• Keywords: vratilo; koncentracija naprezanja; faktor zareznog djelovanja; metoda konačnih elemenata
• Keywords (english): shaft; stress concentrations; notch effect factor; finite element method
• Language: croatian
• URN:NBN: urn:nbn:hr:235:271367
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-09-24 08:52:56