Verjetnostna analiza dinamskega odziva elementov z utrujenostno razpoko

Murnc, Luka (author), Česnik, Martin (mentor)

V zaključni nalogi je predstavljena metoda za kvantitativno vrednotenje utrujenostnih razpok z verjetnostnega vidika, ki temelji na zaznavanju šibkih nelinearnosti v dinamskem odzivu. S sintetičnim eksperimentom je bil obravnavan model z eno prostostno stopnjo, ki replicira realno poškodovano strukturo. Njegov dinamski odziv je bil analiziran z metodo verjetnostne analize. Sledil je realni eksperiment na enostavnem nosilcu, čigar signal je bil analiziran z verjetnostno metodo pred in po utrujenostni poškodbi. Eksperimenti so pokazali, da dinamski odziv v podresonančnem območju vsebuje več nelinearnosti.

• Language: Slovenian
• Keywords: utrujenostna razpoka, nelinearni dinamski odziv, enojna spektralna analiza, značilnost stanja, kvantitativna evalvacija
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [L. Murnc]
• Year: 2023
• Number of pages: XI, 32 str.
• PID: 20.500.12556/RUL-148974
• UDC: 531.391:538.913:620.178.3(043.2)
• COBISS.SI-ID: 164635395
• Publication date in RUL: 02.09.2023

Secondary language

• Language: English
• Title: Probabilistic analysis of dynamic responses of structures with fatigue crack

Abstract

This thesis presents a method for the quantitative evaluation of fatigue cracks from a probabilistic view based on the detection of weak nonlinearities in the dynamic response. The synthetic experiment considered a model with a single degree of freedom, which resembles the behaviour of a real damaged structure. Its dynamic response was analysed with the probabilistic method. This was followed by a real experiment on a simple beam, whose signal was analysed before and after a fatigue crack was induced. The experiments have shown that the dynamic response contains more nonlinearities in the subresonance region.

• Keywords: fatigue crack, nonlinear dynamic response, singular spectrum analysis, status feature, quantitative evaluation