Analiza vpliva geometrijske nelinearnosti na akumulacijo poškodbe pri vibracijskem utrujanju

Cotič, Urban (author), Česnik, Martin (mentor), Boltežar, Miha (comentor)

Predpostavka o linearnosti dinamskih sistemov je v večini inženirskih aplikacij smotrna, v nekaterih primerih, kot je npr. uležajenje rotorja s krogličnimi ležaji, pa temu ni tako. V tem delu je bil računan odziv nelinearnega dinamskega sistema z numerično integracijo v časovni domeni. Za vrsto sistemov, geometrijskih nelinearnosti in tipov vzbujanja je bil dokazan vpliv na amplitudo odziva in akumulacijo poškodbe. Podrobneje so bile analizirane statistične značilke odziva sistema. Predlagana je bila nova metoda za določanje gostote močnostnega spektra sistema pri sinusnem preletu.

• Language: Slovenian
• Keywords: vibracije, nelinearni dinamski sistemi, geometrijska nelinearnost, utrujanje, števne metode, numerična integracija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [U. Cotič]
• Year: 2022
• Number of pages: XXIV, 70 str.
• PID: 20.500.12556/RUL-135890
• UDC: 519.6(043.2)
• COBISS.SI-ID: 102959875
• Publication date in RUL: 31.03.2022

Secondary language

• Language: English
• Title: Effect of geometric non-linearity on damage accumulation in case of vibration fatigue

Abstract

Assuming linearity of a dynamic system is indeed the correct choice for most applications. In some cases however, e.g. fixating a rotor via ball bearings, assumption of linearity does not suffice. The response of a non-linear dynamic system was calculated in this work via numeric integration in the time domain. The effects of geometric non-linearity and type of excitation on the amplitude of the response and damage rate was proven for multiple types of dynamic systems. Statistical parameters of the responses were analysed and a novel method for calculating power spectrum density was proposed.

• Keywords: vibration, non-linear dynamic systems, geometrical non-linearity, fatigue, counting methods, numeric integration