Hibridni postopek dinamičnega sklapljanja podstruktur v frekvenčnem prostoru

Kodrič, Miha (author), Čepon, Gregor (mentor), Boltežar, Miha (comentor)

Verodostojna vibroakustična analiza temelji na zanesljivih dinamskih modelih visoke prostorske ločljivosti. Za postavitev tovrstnih dinamskih modelov se uveljavljajo različne razširitvene metode. Pri tem je eksperimentalni odzivni model z realnimi dinamskimi lastnostmi razširjen na prostostne stopnje numeričnega modela z višjo prostorsko ločljivostjo, kar rezultira v hibridni model. V okviru doktorskega dela smo se osredotočili na razširitveno metodo, ki temelji na sklapljanju ekvivalentnih modelov v frekvenčni domeni. Zanesljivost razširitve je odvisna od konsistentnosti eksperimentalnega odzivnega modela, ki je običajno ocenjena na podlagi primerjave z numeričnim modelom, ta pa ne predstavlja nujno realnega stanja. V ta namen je v okviru doktorske naloge razvita metoda, ki omogoča oceno konsistentnosti posamezne meritve glede na preostale meritve v eksperimentalnem odzivnem modelu. Prikazano je, da odstranitev identificiranih nekonsistentnih meritev znatno poveča zanesljivost razširitvenega procesa. V drugem delu doktorske naloge je izvedena parametrična analiza, na osnovi katere smo identificirali parametre, ki najbolj vplivajo na konsistentnost postopka razširjanja. V tretjem delu smo se osredotočili na razširitev metode sklapljanja ekvivalentnih modelov v obliko, ki omogoča razširjanje dinamskih odzivnih modelov nekomplementarnih fizikalnih veličin. Uporabnost metode je prikazana na primeru~3D natisnjene strukture s kompleksno geometrijo polnila, kjer je predstavljena razširitev preko meritve polja pomikov in specifičnih deformacij. Omenjena metoda omogoča razvoj visoko zanesljivih dinamskih odzivnih modelov ter s tem bolj poglobljen vpogled v dinamske lastnosti analiziranih struktur.

• Language: Slovenian
• Keywords: strukturna dinamika, eksperimentalna modalna analiza, dinamika podstruktur, frekvenčne prenosne funkcije, razširitvene metode, mešanje ekvivalentnih modelov
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [M. Kodrič]
• Year: 2023
• Number of pages: XXVI, [131] str.
• PID: 20.500.12556/RUL-144830
• UDC: 519.61:004.942:531.3:534(043.3)
• COBISS.SI-ID: 145300483
• Publication date in RUL: 15.03.2023

KODRIČ, Miha, 2023, Hibridni postopek dinamičnega sklapljanja podstruktur v frekvenčnem prostoru [online]. Doctoral dissertation. Ljubljana : M. Kodrič. [Accessed 13 June 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=144830

Secondary language

• Language: English
• Title: Hybrid modeling of dynamics substructuring in frequency domain

Abstract

Credible vibroacoustic analysis is based on reliable dynamic models with high spatial resolution. Various expansion methods are used to build such dynamic models. Here, the experimental response model with realistic dynamic properties is extended to the degrees of freedom of the numerical model with higher spatial resolution, resulting in a hybrid model. In the context of the PhD thesis, the focus is on the expansion method based on mixing equivalent models in the frequency domain. The reliability of the extension depends on the consistency of the experimental response model, which is usually evaluated by comparison with numerical models that do not necessarily represent the real situation. To this end, the dissertation developed a method to evaluate the consistency of individual measurements with respect to the other measurements in the experimental response model. It is shown that removing identified inconsistent measurements significantly increases the reliability of the expansion process. In the second part of the thesis, we performed a parametric analysis to identify the most influential parameters for the consistency of the expansion process. In the third part, we focused on extending the method to combine equivalent models in a form that allows expansion of dynamic response models with noncomplementary physical quantities. The applicability of the method is demonstrated by the example of a~3D-printed structure with a complex infill geometry, where the expansion is represented by measuring the field of displacements and specific deformations. The proposed method enables the development of highly reliable dynamic response models that combine physical quantities to provide deeper insight into the dynamic properties of the analyzed structures.

• Keywords: structural dynamics, experimental modal analysis, dynamic substructuring, frequency response functions, expansion methods, system equivalent model mixing