2026-04-05T11:59:10Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4169622025-07-23T07:23:21Zcom_2072_1033col_2072_452951

00925njm 22002777a 4500 dc Maeso Bravo, Claudia Sofia author 2024-07-17 The present thesis addresses the use of Dynamic Mode Decomposition (DMD) for the analysis of vibration patterns in structures, particularly in a cantilever beam. Using a Finite Element Method (FEM) model, synthetic data of the beam response is generated for three different cases: harmonic response, free response and impact response. The generated data is processed with DMD and the output is compared with the original signal, in order to check the ability of DMD in reconstructing said signals. The employed FEM model has been validated experimentally, and proven to be correct for lower frequencies. The last part of this study handles the optimal sensor placement for the impact response case, where the optimal positions for the sensors (in order to perform an accurate reconstruction of the signal) are studied with QR pivoting. The results showed that DMD is not able to interpret a decay in the signal if only one of the main kinematic variables (displacement, velocity and acceleration) is given. In addition, the modes in DMD behave similarly to the normal modes in traditional mechanics, where those with lower eigenvalues are associated to lower oscillation frequencies and longer decay times, and viceversa. It has also been found that the acceleration of the beam in the third case can be reproduced with just 4 sensors. Further work should be carried out in order to include the physical link between acceleration and velocity signals when employing the optimization algorithm that looks for the optimal positions for the sensors. Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica::Vibracions mecàniques Structural dynamics Girders--Vibració Finite element method DMD Sensor Optimization Vibration Beam Structure Dinàmica estructural Bigues--Vibració Elements finits, Mètode dels Study of the vibration pattern synthesis in structures using Dynamic Mode Decomposition (DMD)