Motion based design : solution algorithms to the inverse problem with applications to seismic design
A general solution algorithm to the inverse equilibrium problem is derived. The algorithm finds stiffness coefficients for a given loading and a given set of displacment constraints. Optimization techniques are employed for the statically indeterminate case and for the case of partial displacement specification. The applicability of the method to seismic design of buildings is demonstrated. An inverse eigen-problem is solved for a stiffness distribution that produces a desired fundamental mode shape. The stiffness is then scaled based on the magnitude of the excitation with the use of response spectra. Emphasis is placed on stiffness proportional damping, which can be generated from the physical placement of dampers. Thesis Supervisor: Jerome J. Connor Title: Professor of Civil and Environmental Engineering Acknowledgments I would like to take this opportunity to thank the people to whom I am indebted for this thesis. First of all, I would like to thank my father and mother, Wilfred and Lorraine Gallegos. I would not have had the opportunity to write this thesis, were it not for your financial and emotional support. You have been very supportive of all my efforts without trying to influence any of the decisions I have made. A very heartfelt thanks to my brother and sister, Wilfred Jr. and Anita. You have always been, and will continue to be excellent role models. A special thanks to my advisor Professor Jerome J. Connor for an extremely interesting and challenging research topic. But more importantly, I thank you for helping me find a new direction in life. It was a pleasure working with you. Thanks to Miguel Licona for providing a state space simulator which was used to analyze the designs. I dedicate this thesis to my grandmothers, Corina V. Duran and Lucia Lopez. You provided me with a stable cultural environment and a unique perspective on life. I have always drawn and will continue to draw upon your wise words of wisdom in times of need.
Introduction to motion based design
This text provides a basis for the preliminary design of motion sensitive structures and bridges the gap between conventional structural design and the emerging field of motion based design. It contains an outline of basic concepts, computational procedures and behavioural issues for structural motion control. Examples illustrating the application of the motion based design paradigm to a range of buildings are also presented. Topics covered include optimal stiffness distributions, the role of damping in controlling motion, tuned mass dampers, base isolation systems and active control.
Optimum Design of Multistory Multispan Frames for Prescribed Elastic Compliance
ABSTRACT This paper presents an analytical method for minimum cost design of regular rectangular building frames for constrained elastic compliance. The method, consisting of a semi-inverse method and a design region extension procedure, is illustrated by two classes of exact solutions. It is shown that the relative story displacements are almost uniformly distributed in an optimally designed frame with almost uniform story heights and that the solutions enable one to calculate all maximum member-end stresses from member-end curvatures. It is suggested that the proposed design formulas may be utilized for design problems, subject to relative story displacement and stress constraints. Since these solutions are shown to be dependent upon the nature of the prescribed minimum stiffnesses, a method of finding a practically reasonable set of minimum stiffnesses is also presented.