Modal identification and Finite element model updating

Autor: Yu-Yu Shen, 沈祐宇
Rok vydání: 2014
Druh dokumentu: 學位論文 ; thesis
Popis: 102
This research focues on the modal identification of high speed rail structures by ARX model using the vibration test data. By that way, the identified dynamics characteristics of structure were used as reference basis for the updating of the finite element method, in order to reduce the model uncertainties of analysis model. The parameters of a dynamic system are calculated by least squares method in ARX model using the time-history data, including the external forces (input) and the displacements or acceleration (output) .The nature frequencies, damping ratios and the mode shapes of structure system can be identified. To verify the feasibility of ARX method, the dynamics characteristics of a cantileaver plate model were identified using the input/output data created by numerical simulation. To grasp the dynamics characters of high speed rail system, the impact model testing was conducted. The dynamic characteristics of rail, truck, and viaduct structures where identified by using the experimental data To reduce the model uncertainties, the equivalent material parameters of finite element model was adjusted to archieve the minimum difference between the identified and the calculated natural frequencies.
Databáze: Networked Digital Library of Theses & Dissertations