Spektralna analiza zamora brodskih konstrukcija

scientific master's theses

• Title (english): Spectral fatigue analysis of ship structures
• Author: Smiljko Rudan
• Mentor: Ivo Senjanović (mentor)
• Committee member: Slobodan Kralj (predsjednik povjerenstva)
• Committee member: Ivo Senjanović (član povjerenstva)
• Committee member: Tomislav Filetin (član povjerenstva)
• Committee member: Mirko Husnjak (član povjerenstva)
• Committee member: Nenad Vulić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2002-02-22, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Shipbuilding
• Universal decimal classification (UDC): 629.5 - Watercraft engineering

Abstract

Gradnju suvremenih brodova odlikuje izrada nestandardnih strukturnih detalja, korištenje čelika povišene čvrstoće, optimizacija konstrukcije uz pouzdanije određivanje kriterija nosivosti. Takve značajke gradnje često su praćene povećanim rizikom zamornog oštećenja. Zamor materijala u strukturnim detaljima brodskih konstrukcija prepoznat je kao značajan problem i predmet je intenzivne znanstveno-istraživačke aktivnosti. U radu je prikazan kratak pregled postupaka analize zamora brodskih konstrukcija. \Naglasak je stavljen na spektralnu metodu analize zamora kao sofisticiranog načina proračuna očekivane dinamičke izdržljivosti konstrukcije. Prikazana su i napravljena sva četiri koraka spektralne analize. Izrađeni su globalni i lokalni modeli konačnih elemenata i određene prijenosne funkcije naprezanja za tipičan strukturni detalj tankera s dvostrukom oplatom. Posebno je prikazan postupak određivanja žarišnih naprezanja. Na osnovi izračunatih prijenosnih funkcija određena je dugoročna razdioba naprezanja i izračunato je zamorno oštećenje detalja. Dobiveni rezultati uspoređeni su s rezultatima pojednostavljenog proračuna i nekim rezultatima poznatim iz literature.

Abstract (english)

Building of modern cargo ships is characterized by nonstandard structural details design, the application of high tensile steels and the construction optimization by reliable determination of load carrying capability. Such shipbuilding characteristics are often accompanied by increased risks of fatigue damage. Fatigue of structural details in ship constructions is recognized as an important problem and has become a subject of intensive scientific research. A short review of the methods for fatigue analysis of ship constructions is presented in this thesis. The emphasis is on the spectral fatigue analysis method, which is a sophisticated fatigue strength evaluation method. All four steps of the spectral analysis method are presented. Global and local finite element models were generated and stress transfer functions for a typical structural detail of a double hull tanker were determined. Special attention is paid to hot-spot stresses evaluation procedure. On the basis of known stress transfer functions, a long-term stress range distribution was evaluated and then fatigue damage was calculated. The obtained results were compared with the results of simplified fatigue damage calculation and the published results.

• Keywords: brodska konstrukcija; strukturni detalji; zamor materijala; žarišna naprezanja; spektralna analiza
• Keywords (english): ship structure; structural details; fatigue; hot-spot stress; spectral analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:235:045446
• Study programme: Title: Naval Architecture - mr.sc.; Study programme type: university; Study level: postgraduate; Academic / professional title: magistar znanosti (magistar znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-12-28 13:39:38