Proračun čvrstoće i krutosti startnog bloka za plivanje primjenom metode konačnih elemenata

undergraduate thesis

• Title (english): Strength and stiffness assessment of the swimming starting block using finite element method
• Author: Ivan Gotesman
• Mentor: Tomislav Lesičar (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2025-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Startni blok ključan je element u natjecateljskom plivanju, jer plivačima omogućuje stabilan, učinkovit i eksplozivan početak utrke. Sastoji se od čvrstog postolja s pomičnom nagnutom platformom, koja plivačima osigurava optimalan odraz, te čelične konstrukcije s hvatištima namijenjenima za leđni start. Tema ovog završnog rada je proračun čvrstoće i krutosti čelične konstrukcije startnog bloka za leđni start.
Na početku rada provedena je analiza opterećenja koje djeluje na startni blok tijekom starta plivača. Prije numeričke analize startnog bloka za leđni start, proveden je postupak verifikacije konačnih elemenata na primjeru s poznatim analitičkim rješenjem. U tu svrhu korišteni su gredni, ljuskasti i tetraedarski elementi, pri čemu su odabrani optimalni elementi za daljnju analizu.
Numerički proračun čelične konstrukcije startnog bloka proveden je u programskom paketu Abaqus. Proračuni su se izvodili postupno, prvo s grednim, zatim s ljuskastim, a potom s tetraedarskim konačnim elementima. Diskretizacija je provedena s različitim brojem konačnih elemenata kako bi se osigurala konvergencija rješenja. Proračun grednim elementima omogućio je identifikaciju područja s povećanom koncentracijom naprezanja te dao početne smjernice za daljnju analizu. U proračunu ljuskastim i tetraedarskim elementima korišteni su detaljniji modeli, uključujući bazu startnog bloka, vijke i podložne pločice, kako bi se preciznije opisala raspodjela naprezanja i deformacija. Dobiveni rezultati uspoređeni su i prokomentirani, čime su doneseni zaključci o strukturnoj pouzdanosti bloka za leđni start.

Abstract (english)

The starting block is a crucial element in competitive swimming, as it provides swimmers with
a stable, efficient, and explosive start to the race. It consists of a sturdy base with an adjustable
inclined platform that ensures optimal push-off and a steel structure with handgrips designed
for backstroke start. The topic of this thesis is the strength and stiffness analysis of the steel
structure of a backstroke starting block.
At the beginning of the study, an analysis of the loads acting on the starting block during a
swimmer’s start was conducted. Before performing the numerical analysis of the backstroke
starting block, a finite element verification procedure was conducted on an example with a
known analytical solution. For this purpose, beam, shell, and tetrahedral elements were used,
and the most suitable elements were selected for further analysis.
The numerical calculation of the steel structure of the starting block was conducted using the
Abaqus software. The calculations were performed in stages, first using beam elements,
followed by shell and tetrahedral elements. Discretization was conducted with different
numbers of finite elements to ensure solution convergence. The beam element analysis
identified areas with increased stress concentration and provided initial guidelines for further
analysis. In the shell and tetrahedral element calculations, more detailed models were used,
including the starting block base, bolts, and washers, to describe the distribution of stress and
deformation more accurately. Obtained results were compared and discussed, leading to
conclusions regarding the structural reliability of the backstroke starting block.

• Keywords: startni blok; metoda konačnih elemenata; numerička analiza; Abaqus; čvrstoća; krutost
• Keywords (english): starting block; finite element method; numerical analysis; Abaqus; strength; stiffness
• Language: croatian
• URN:NBN: urn:nbn:hr:235:363409
• 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: 2025-02-20 13:03:36