Određivanje i verifikacija novog korektivnog faktora za statističku procjenu širokopojasnog spektralnog zamora

master's thesis

• Title (english): Determination and verification of a new correction factor for statistical assessment of broadband spectral fatigue
• Author: Marko Matijević
• Mentor: Zvonimir Tomičević (mentor)
• Mentor: Damjan Čakmak (komentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-07-21, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Ovaj rad bavi se analizom zamora materijala uslijed visokocikličkog opterećenja. Usmjeren je na razvoj i usporedbu novih korektivnih faktora koji bi kod uskopojasnog zatvorenog rješenja umanjili preveliku konzervativnost.
Na početku rada opisan je visokociklički zamor te je objašnjena S-N metoda proračuna zamora za visokocikličko opterećenje. Opisane su metode brojanja ciklusa prema normi ASTM E1049-85(2011.).
Prikazan su spektralni parametri stohastičkog signala u frekvencijskoj domeni. Objašnjena je pretvorba signala iz frekvencijske u vremensku domenu. Prikazan je stohastični signal sa svim uvjetima koje treba zadovoljiti da bi bio slučajan.
U završnom dijelu rada predstavljeni su rezultati analize novih korektivnih faktora s različitim spektrom frekvencija i naprezanja. Napravljena je grafička usporedba rezultata s referentnim metodama te je prikazana prosječna relativna greška.

Abstract (english)

This thesis deals with the analysis of material fatigue due to high cyclic loading. It is focused at the development and comparison of new corrective factors that would reduce excessive conservatism in a Narrow-band closed solution.
At the beginning of the thesis, high-cycle fatigue is described and the S-N fatigue calculation method for high-cycle loads is explained. Cycle counting methods according to ASTM E1049-85 (2011) are described.
The spectral parameters of the stochastic signal in the frequency domain are presented. The signal conversion from the frequency domain to the time domain is explained. A stochastic signal is shown with all the conditions that must be met in order for it to be random.
In the final part of the paper, the results of the analysis of new corrective factors with different spectrum frequencies and stresses are presented. A graphical comparison of the results with reference methods was made and the average relative error was shown.

• Keywords: zamorni lom; stohastička povijest naprezanja; vremenska domena; frekvencijska domena; korektivni faktori; metoda toka kiše; spektralne metode; uskopojasni signal; širokopojasni signal
• Keywords (english): fatigue fracture; stochastic stress history; time domain; frequency domain; correction factors; rainflow method; spectral methods; Narrowband signal; Broadband signal
• Language: croatian
• URN:NBN: urn:nbn:hr:235:535561
• 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: 2023-07-09 20:31:48