ACTIVE CONTROL OF PENDULUM TUNED MASS DAMPERS FOR TALL BUILDINGS SUBJECT TO WIND LOAD Dissertation Submitted to The School of Engineering of the UNIVERSITY OF DAYTON In Partial Fulfillment of the Requirements for The Degree of Doctor of Philosophy in Engineering By Mohamed A. Eltaeb, M.S. UNIVERSITY OF DAYTON Dayton, Ohio December, 2017 ACTIVE CONTROL OF PENDULUM TUNED MASS DAMPERS FOR TALL BUILDINGS SUBJECT TO WIND LOAD Name: Eltaeb, Mohamed Ali APPROVED BY: ------------------------------------- ------------------------------------- Reza Kashani, Ph.D. Dave Myszka, Ph.D. Committee Chairperson Committee Member Professor Associate Professor Department of Mechanical Department of Mechanical and Aerospace Engineering and Aerospace Engineering ------------------------------------- ------------------------------------- Elias Toubia, Ph.D. Muhammad Islam, Ph.D. Committee Member Committee Member Assistant Professor Professor Department of Civil and Department of Mathematics Environmental Engineering ------------------------------------- ------------------------------------- Robert J. Wilkens, Ph.D., P.E. Eddy M. Rojas, Ph.D., M.A., P.E. Associate Dean for Research and Innovation Dean, School of Engineering Professor School of Engineering ii © Copyright by Mohamed A. Eltaeb All rights reserved 2017 ABSTRACT ACTIVE CONTROL OF PENDULUM TUNED MASS DAMPERS FOR TALL BUILDINGS SUBJECT TO WIND LOAD Name: Eltaeb, Mohamed A. University of Dayton Advisor: Dr. Reza Kashani Wind induced vibration in tall structures is an important problem that needs effective and practical solutions. TMDs in either passive, active or semi-active form are the most common devices used to reduce wind-induced vibration. The objective of this research is to investigate and develop an effective model of a single multi degree of freedom (MDOF) active pendulum tuned mass damper (APTMD) controlled by hydraulic system in order to mitigate the dynamic response of the proposed tall building perturbed by wind loads in different directions. The proposed APTMD can be tuned to the first three dominant frequencies of the targeted structure in three directions (X, Y, γ) simultaneously and add damping to the corresponding modes. Another design requirement of the APTMD is the capability of adjusting its properties (stiffness and damping) to compensate for the detuning occurred due to the varying operating conditions such as an environment, or imposed loading. These supplemental damping devices offer attractive means to protect iii tall buildings against natural hazards and make a genuine contribution to the building sway, which has such a great economic and social effects. The targeted structure for the proposed approach in this work is a MDOF model representing a full scale concrete tall building. This building is a modern high-rise building designed as a flexible and slender structure, asymmetric geometry, excited by wind loads in multiple directions. The building has 41 stories above the ground where each floor has three degrees of freedom, two in 푥, 푦 directions (planar) and one around the axis perpendicular to 푥 − 푦 plane γ (rotational). The first 15 modes of the building will be included in this study, five modes in each direction. The innovative idea of this work is involving the Stewart Platform, was originally designed in 1965 as a flight simulator, and it is still commonly used for that purpose. It is controlled by hydraulic system that is used for motion control (position control) of the pendulum TMD relative to the building. The pendulum itself is a passive device but as it is comprised with active-controlled hydraulic actuators, the legs of the Stewart Platform in our case, it becomes an active system. The electrohydraulic servo valve is used to control the hydraulic system of the proposed active PTMD because it can offer more responsive and accurate control tasks in a timely manner. By combining the muscle of the hydraulic power and the accuracy of electrical control, electrohydraulic control valves can control hydraulic systems precisely and efficiently. The desired control force is calculated from the acceleration, velocity, and displacement feedbacks of the MDOF system and active PTMD in order to achieve the different tuning frequencies and damping effects. The proposed tasks for the conduct of iv ‘Multi Tuning-frequency Passive/on demand Active Pendulum Tuned Mass Damper’ research are: a) To synthesize the control scheme for active Pendulum TMD that can be tuned simultaneously to multiple directions replacing multiple more massive PTMDs. Such attributes lowers the cost, weight and space requirement associated with dampening multiple modes using multiple TMDs. b) To increase the effectiveness of the proposed active PTMD, which leads to lowering its weight (50% less) without degrading its performance. With its small size and multi-frequency tuning capacity, the proposed APTMD is as effective as a passive TMD many times more massive. c) To obtain a high fidelity model of the structure targeted for damping The synthesis and analysis of the proposed passive/on-demand active PTMD is presented. The effectiveness of the proposed tuned mass damper is numerically demonstrated, by interfacing its model with that of a high-rise building. v I dedicate my dissertation work to my family. A special feeling of gratitude to my loving parents, Al-Haj Ali Eltaeb and Fatima Eblaiblu whose words of encouragement and support have provided me with strength and patience. I also dedicate this dissertation to my darling wife, Amna who has supported me throughout my study journey far from home. I will always appreciate all she has done. vi ACKNOWLEDGMENTS My special thanks are in order to my committee chair Professor Dr. Reza Kashani, my advisor, for providing the time and resources necessary for the work contained herein, and for directing this dissertation and bringing it to its conclusion with patient guidance and expertise. It has been an honor to be his Ph.D. student. I would also like to express my appreciation to my committee members, Dr. Mohammad Islam, Dr. Dave Myszka, and Dr. Elias Toubia. Also, I would like to acknowledge friends and family members who supported me during my work on this research. First and foremost, I would like to thank my father and mother for their constant love and pray for me to get success. And most of all for my loving, supportive, and patient wife Amna whose faithful support during the stages of this work is so appreciated. Also, I thank my darling children for their constant support and encouragement throughout this work. vii TABLE OF CONTENTS ABSTRACT ....................................................................................................................... iii DEDICATION ................................................................................................................... vi ACKNOWLEDGMENTS ................................................................................................ vii LIST OF FIGURES ........................................................................................................... xi LIST OF TABLES ........................................................................................................... xiv I. INTRODUCTION ........................................................................................................ 1 1.1 Problem Statement ...................................................................................................1 1.2 Research Objectives .................................................................................................3 1.3 Approach ..................................................................................................................5 II. LITERATURE REVIEW AND BACKGROUND ...................................................... 6 2.1 Tall Buildings...........................................................................................................6 2.1.1 Lateral Loads Affecting Tall Buildings ...................................................... 6 2.1.1.1 Wind Loads ............................................................................... 7 2.1.1.2 Seismic loads ............................................................................ 8 2.1.2 Wind Induced Building Motion .................................................................. 8 2.1.3 Design Approaches Against Wind Excitation .......................................... 11 2.1.3.1 Mechanical Design Approach ................................................. 12 2.1.3.2 Comfort Criteria (human response to building motion) ......... 13 2.1.4 Design Approaches Against Seismic Excitation ....................................... 13 2.2 Structural Vibration ...............................................................................................14 2.2.1 Control of Vibration .................................................................................. 15 2.2.1.1 Structure Modification and/ or Damping ................................ 16 2.2.2 Vibration Control Systems ........................................................................ 17 2.2.2.1 Passive Control System........................................................... 17 2.2.2.2 Active Control System ............................................................ 18 2.2.2.3 Semi Active Control System ................................................... 20 2.3 Tuned Mass Damper (TMD) .................................................................................21 2.3.1 Passive Tuned Mass Damper (PTMD)