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.
Tests of composite beams with web holes
Tests of composite beams comprising a concrete slab supported on a steel deck and a steel wide-flange shape containing large web openings are described. Special attention is directed to the amount of shear connection between slab and steel section in the region of a web hole, and on the effect of construction loads acting on the steel section prior to composite action being effective.It is shown that limited shear connection at the hole will significantly affect the strength when loading produces a high shear-to-moment ratio, and a theory is presented which conservatively takes this into account. The effect of construction loads on unshored construction is shown to be small when these do not exceed 60% of the non-composite beam resistance at the hole.