Skip to Main Content
Frequently Asked Questions
Submit an ETD
Global Search Box
Need Help?
Keyword Search
Participating Institutions
Advanced Search
School Logo
Files
File List
case1054567783.pdf (2.7 MB)
ETD Abstract Container
Abstract Header
Dynamic substructuring by the boundary flexibility vector method of component mode synthesis
Author Info
Abdallah, Ayman Ahmed
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=case1054567783
Abstract Details
Year and Degree
1990, Doctor of Philosophy, Case Western Reserve University, Civil Engineering.
Abstract
Component mode synthesis (CMS) is a method of dynamic analysis, for structures having a large number of degrees of freedom (D.O. F.). These structures often required lengthy computer CPU time and large computer memory resources, if solved directly by the finite-element method (FEM). In CMS, the structure is divided into independent components in which the D.O.F. are defined by a set of generalized coordinates defined by displacement shapes. The number of the generalized coordinates are much less than the original number of physical D.O.F., in the component. The displacement shapes are used to transform the component property matrices and any applied external loads, to a reduced system of coordinates. Reduced system property matrices are assembled, and any type of dynamic analysis is carried out in the reduced coordinate system. Any obtained results are back transformed to the original component coordinate systems. In all conventional methods of CMS, the mode shapes used for components, are dynamic mode shapes, supplemented by static deflected shapes. Historically, all the dynamic mode shapes used in conventional CMS are the natural modes (eigenvectors) of components. This work presents a new method of CMS, namely the boundary flexibility vector method of CMS. The method provides for the incorporation of a set of static Ritz vectors, referred to as boundary flexibility vectors, as a replacement and/or supplement to conventional eigenvectors, as displacement shapes for components. The generation of these vectors does not require the solution of a costly eigenvalue problem, as in the case of natural modes in conventional CMS, and hence a substantial saving in CPU time can be achieved. The boundary flexibility vectors are generated from flexibility (or stiffness) properties of components. The formulation presented is for both free and fixed-interface components, and for both the free and forced vibration problems. Free and forced vibration numerical examples are presented to verify the accuracy of the method and the saving in CPU time. Compared to conventional methods of CMS, the results indicate that by using the new method, more accurate results can be obtained with a substantial saving in CPU time.
Committee
Arthur Huckelbridge (Advisor)
Pages
142 p.
Keywords
Dynamic substructuring boundary flexibility vector component mode synthesis
Recommended Citations
Refworks
EndNote
RIS
Mendeley
Citations
Abdallah, A. A. (1990).
Dynamic substructuring by the boundary flexibility vector method of component mode synthesis
[Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1054567783
APA Style (7th edition)
Abdallah, Ayman.
Dynamic substructuring by the boundary flexibility vector method of component mode synthesis.
1990. Case Western Reserve University, Doctoral dissertation.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=case1054567783.
MLA Style (8th edition)
Abdallah, Ayman. "Dynamic substructuring by the boundary flexibility vector method of component mode synthesis." Doctoral dissertation, Case Western Reserve University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=case1054567783
Chicago Manual of Style (17th edition)
Abstract Footer
Document number:
case1054567783
Download Count:
1,013
Copyright Info
© 1990, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.