Earthquake Engineering and Engineering Vibration

, Volume 10, Issue 2, pp 219–227

Extraction of real modes and physical matrices from modal testing


DOI: 10.1007/s11803-011-0060-6

Cite this article as:
Wang, T., Zhang, L. & Tee, K.F. Earthq. Eng. Eng. Vib. (2011) 10: 219. doi:10.1007/s11803-011-0060-6


A technique to extract real modes from the identified complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtained. The theoretical derivation of the method is provided in detail. An 11-DOF vibration system is used to validate the algorithm, and to analyze the effects of the number of modes utilized and measurement DOFs on the extraction results. Finally, the method is used to extract real modes from both experimental modal analysis and operational modal analysis.


modal analysiscomplex modereal modenormalized mode shapemodal mass

Copyright information

© Institute of Engineering Mechanics, China Earthquake Administration and Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  1. 1.MOE Key Lab of Structural Mechanics and Control for AircraftNanjing University of Aeronautics and AstronauticsNanjingChina
  2. 2.Department of Civil EngineeringUniversity of GreenwichGreenwichUK
  3. 3.Institute of Vibration EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina