Vahid Heydari - Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Mohammd Ahmadi Balootaki - Department of Mechanical Engineering, Shahid Nikbakht Faculty, University of Sistan and Baluchestan, Zahedan, Iran Faculty of Shahid Bahonar, Sistan and Baluchestan Branch, Technical and Vocational University (TVU), Zahedan, Iran.
Mohammad Orak - Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Mehdi Salehi - Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran

In this paper, the problems arising from determining the modal properties of large and complex structures are investigated. For this purpose, the free interface component mode synthesis method has been used. In the following, Singular-Value Decomposition (SVD) is applied as a powerful mathematical tool to determine the appropriate coordinates to participate in the coupling process. Also, the effective error resources including modal shear error and the continuous systems overlapping error and their solution are introduced. Initially, a discrete system has been employed to investigate the free interface component mode synthesis method. Eventually, the studied main samples in this research are beam, plate and cylindrical shell. It is worth noting that the application of this method on the cylindrical shell has not been observed in previous researches.

Component Mode Synthesis, Free Interface Method, Modal Analysis, Substructures, Singular-Value Decomposition Method