Inlämning av Examensarbete / Submission of Thesis

wei sun BTH-AMT-EX--2008/D-07--SE, pp. 60. TEK/avd. för maskinteknik, 2008.

The work

Författare / Author: wei sun
Titel / Title: Output Only Modal Analysis-Scaled mode shape by adding small masses on the structure
Abstrakt Abstract:

In this paper an outline is given of output only modal analysis, some of the known technologies are briefly introduced.
Due to the unknown input force of the output only modal analysis, the mode scaling factor can not be estimated, only the un-scaled mode shape can be obtained from Frequency Response Functions. This paper introduces one simple method of adding masses on the structure. The natural frequency shift caused by the structure mass change is used to get the scaling factor and scaled mode shapes.
The simple method is illustrated on a computer simulation of one four-degree-freedom lumped system and also on an output only measurement on a short bridge in the Blekinge Institute of Technology.

Ämnesord / Subject: Maskinteknik - Mechanical Engineering\Structural Dynamics

Nyckelord / Keywords: Output Only Modal Analysis/Frequency Response Function/Mode shape/Scaling factor/Impulse Response Function

Publication info

Dokument id / Document id:
Program:/ Programme Masters programme in Mechanical Engineering, 60 points
Registreringsdatum / Date of registration: 05/09/2008
Uppsatstyp / Type of thesis: D-Uppsats/Magister/Master


Handledare / Supervisor: Prof Kjell Ahlin
Examinator / Examiner: Ansel Berghuvud
Organisation / Organisation: Blekinge Institute of Technology
Institution / School: TEK/avd. för maskinteknik
S-371 41 Karlskrona
+46 455 38 50 00

Files & Access

Bifogad uppsats fil(er) / Files attached: bth_amt_ex_2008d07_se.pdf (525 kB, öppnas i nytt fönster)