Assessment of structural performance of steel building on shake table using multi input multi output models

3―1 Assessment of Structural Performance of Steel Building on Shake Table Using Multi-Input Multi-Output Models Academic Year 2010 Ho Thu Hien Master’ ster ’s Thesis Academic Year Year 2010 2010 Assessment of Structural Performance of Steel Building on Shake Table Using Multi-Input Multi-Output Models Ho Thu Hien （Student ID No.: 80823789） Advisor Professor Akira, MITA September 2010 Keio University Graduate School of Science and Technology School of Science for Open and Environmental Systems Systems Thesis Abstract As we know, earthquakes have caused many serious damages; that is why it is needed to study the health of buildings after these earthquakes After a large earthquake, evaluation of damage of structures is an important task for health assessment Vibrations of buildings give us valuable information on it Changes in the modal properties like natural frequencies, modal shapes and modal damping are very important to assess the structures Among the representative structural characteristics, natural frequencies provide the global information However they are relatively simple, accurate to measure and easy to obtain Besides, the changes in frequencies must be considered to assess the health of structure When the frequency shifts give the general health assessment, the mode shape changes can be categorized up to the higher level of damage identification – determination of the geometric location of the damage This study will consider the frequencies shifts and their mode shapes with various levels of seismic excitations The excitations are represented by different intensity levels of the 1995 Hyogoken Nanbu Earthquake that are obtained in JR – Takatori Station The acceleration data of E–defense tests on full scale 4-story steel building will be analyzed Five sets of acceleration data were measured at center and corners on shake table and stories of the full-scale model were considered as inputs and outputs signals of many types of multi-input multi-output (MIMO) models From the defined models, some first mode natural frequencies of structure will be obtained and compared to each other By analyzing the two first mode natural frequencies of X and Y directions, the capacity of structure will be assessed with its performance The aim of this research is to assess the capacity of a steel building after a seismic activity using real-size shake table tests Course No １－１ １－２ １－３ １－４ １－５ １－６ ２－１ ２－２ ２－３ ２－４ ２－５ ３－１ ３－２ ３－３ ３－４ ３－５ ３－６ Sub school: Fundamental Science and Technology Mathematics Physics Molecular Chemistry Applied Physics and Physico-Informatics Chemical Biology Biosciences and Informatics Sub school: Integrated Design Engineering Multidisciplinary and Design Science System Integration Engineering Smart Device and System Engineering Photonics and Image Information Engineering Science and Technology for Designing Functions Sub school: Science for Open and Environmental Systems Space and Environment Design Engineering Science of Environment, Resources and Energy Applied and Computational Mechanics Computer Science Smart Media Communication Engineering Open Systems Management ABSTRACT As we know, earthquakes have caused many serious damages; that is why it is needed to study the health of buildings after these earthquakes After a large earthquake, evaluation of damage of structures is an important task for health assessment Vibrations of buildings give us valuable information on it Changes in the modal properties like natural frequencies, modal shapes and modal damping are very important to assess the structures Among the representative structural characteristics, natural frequencies provide the global information However they are relatively simple, accurate to measure and easy to obtain Besides, the changes in frequencies must be considered to assess the health of structure When the frequency shifts give the general health assessment, the mode shape changes can be categorized up to the higher level of damage identification – determination of the geometric location of the damage This study will consider the frequencies shifts and their mode shapes with various levels of seismic excitations The excitations are represented by different intensity levels of the 1995 Hyogoken Nanbu Earthquake that are obtained in JR – Takatori Station The acceleration data of E–defense tests on full scale 4-story steel building will be analyzed Five sets of acceleration data were measured at center and corners i on shake table and stories of the full-scale model were considered as inputs and outputs signals of many types of multi-input multi-output (MIMO) models From the defined models, some first mode natural frequencies of structure will be obtained and compared to each other By analyzing the two first mode natural frequencies of X and Y directions, the capacity of structure will be assessed with its performance The aim of this research is to assess the capacity of a steel building after a seismic activity using real-size shake table tests ii DEDICATION To my lovely and happy family, THEUHF! iii ACKNOWLEDGEMENTS First of all, I would like to express my sincere gratitude and thanks to my advisor Professor Akira Mita for his kind advices, valuable suggestions, invaluable guidance, moral support and effective encouragement throughout the course of this study My special gratitude is due to all my dear friends: Ms Kondo, Ms Take, Ms Hasegawa, Mr Okamoto, Mr Oshihara, Mr Kosakai, Ms Nakamura, Ms Maho, Ms Goshima, Ms Ishikawa, Mr Mutara, Mr Sato, Mr Ichimura and others, especially, international students (Mr Xing, Ms Soroka, Ms Chua and Mr Kelpal) for making my time spent at Keio University an unforgettable memory as well as for what they helped for me to overcome lot of difficulties in foreign environment I would like to thank to the Ministry of Education, Science and Culture of Japan (Monbukagakusho) for the full financial support and the research facilities they provided during my study Finally, but not the least, I would like to thank and dediacte my mother, my husband and my son, for all the trust, support that they gave me Without their love, encouragement, inspiration and sacrifice, this work could hardly be completed iv TABLE OF CONTENTS Page ABSTRACT i DEDICATION iii ACKNOWLEDGMENTS iv TABLE OF CONTENTS v LIST OF FIGURES vii LIST OF TABLES x INTRODUCTION 1.1 Overviews 1.2 Background 1.3 Objectives 1.4 Organization of this Thesis EXPERIMENTAL DATA 10 2.1 Introduction 10 2.2 E-Defense 11 2.3 Full-scale 4-story steel building 12 v 2.4 Experiment 15 2.5 Results of experiments 16 SYSTEM IDENTIFICATION FOR STRCUTURAL HEALTH MONITORING 19 3.1 Introduction 19 3.2 Nonparametric identification 26 3.3 Parametric identification 28 3.4 Experimental verification 34 MULTI-INPUT MULTI-OUTPUT MODELS 43 4.1 Introduction 43 4.2 MIMO identification method 45 4.3 Application of MIMO models 46 4.3.1 Type of models 46 4.3.2 Application 48 CONCLUSION 59 REFERENCES 61 vi ... Year Year 2010 2010 Assessment of Structural Performance of Steel Building on Shake Table Using Multi- Input Multi- Output Models Ho Thu Hien （Student ID No.: 80823789） Advisor Professor Akira, MITA... acceleration data were measured at center and corners i on shake table and stories of the full-scale model were considered as inputs and outputs signals of many types of multi- input multi- output. .. Application of MIMO models 46 4.3.1 Type of models 46 4.3.2 Application 48 CONCLUSION 59 REFERENCES 61 vi LIST OF FIGURES Page Figure 2.1 Shake table set in position 12 Figure 2.2 Full-scale 4-story steel