TY - BOOK AU - Widjaja,Joko Harsono AU - Worsak Kanok-Nukulchai, AU - Karasudhi,Pisidhi AU - Wireland,Martin ED - Lee Foundation, Singapore, TI - A dynamic frontal scheme for eigensolutions of large structural systems T2 - Thesis PY - 1981/// CY - Bangkok PB - Asian Institute of Technology KW - Structures, Theory of KW - Matrix methods KW - Eigenvalues N1 - A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology; Thesis (M.Eng.) - Asian Institute of Technology, 1981 N2 - A numerical method for extracting eigen solutions associated with lower modes of large structural systems is developed , with an aim to alleviate storage requirement. Dynamic frontal scheme is proposed to identify dynamically inactive degrees-of-freedom by means of a ' cut-off slave eigenvalue'. These degrees-of-freedom will be treated as being slave to a few active ones. Guyan method is employed at this stage to obtain the first approximation to eigen solutions for the condensed system. Subsequently, a respective Guyan eigenvalue can be used to form t he frequency-dependent transformation matrix for upgrading the condensed system for a particular mode , This condensed system will be solved by inverse iterations taking the Guyan eigen-value as the initial shift and its associated eigenvector as initial vector. The cycle of condensed system upgrading and inverse iterations will be repeated with updated shift until the improved eigen solution converges. Several numerical examples are presented to show the validity and effectiveness of the method. As only a few lower modes of large structural systems are considered in common practice, this method should be very attractive, especially when the computer storage is limited UR - http://203.159.5.9/ait-thesis/detail.php?q=B21766 ER -