scholarly journals Coverage intensity of optimal sensors for common, isolated, and integrated steel structures using novel approach of FEM-MAC-TTFD

2019 ◽  
Vol 15 (8) ◽  
pp. 155014771985756 ◽  
Author(s):  
Mehdi Firoozbakht ◽  
Hamidreza Vosoughifar ◽  
Alireza Ghari Ghoran
Keyword(s):  
Base Isolation ◽  
Sensor Placement ◽  
Time History ◽  
Shear Wall ◽  
Optimal Sensor Placement ◽  
Modal Assurance Criterion ◽  
Moment Resisting Frame ◽  
Steel Shear Wall ◽  
Significant Difference ◽  
Moment Resisting

The coverage intensity of sensors is the most important issue on structural health monitoring technique. The geometric configuration of sensors must be optimized based on coverage intensity with proper objectives. In this article, a novel algorithm for optimal sensor placement in various steel frames was evaluated. These frames including moment-resisting frame, moment-resisting frame with base isolation, and moment-resisting frame with base isolation with steel shear wall were selected for case studies. This approach was proposed based on combination of common optimal sensor placement algorithm and nonlinear time history analysis. A new method called transformed time history to frequency domain approach was evaluated to transform nonlinear time history analysis results to frequency domain and then the effective frequencies according the maximum range of Fourier amplitude were selected. The modified type of modal assurance criterion values can be achieved from modal assurance criterion with the exact seismic displacement. All of novel optimal sensor placement processes were done through FEM-MAC-TTFD code modeled and developed in MATLAB by authors of this article. The results show that there is good relative correlation between the sensors number and coverage intensity obtained with modal and modified modal assurance criterion approaches for moment-resisting frame system, but for integrated frame such as moment-resisting frame with base isolation and moment-resisting frame with base isolation with steel shear wall, the modified modal assurance criterion approach is better approach. There is no significant difference between coverage intensity of sensors for top joints between modal assurance criterion and modified modal assurance criterion approaches for moment-resisting frame, moment-resisting frame with base isolation, and moment-resisting frame with base isolation with steel shear wall systems ( R2 = 0.994, 0.986, and 0.724, respectively). It was found that if reference point is located in center of frame, there is significant difference between modal assurance criterion and modified modal assurance criterion approaches, and modified modal assurance criterion generated slightly better results.

scholarly journals ANALISIS PERIODA BANGUNAN DINDING GESER DENGAN BASE ISOLATOR AKIBAT GAYA GEMPA

Teras Jurnal ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 263
Author(s):  
Mul Muliadi Adi ◽  
M. Kabir Kabir Ihsan
Keyword(s):  
Seismic Design ◽  
Time History ◽  
Shear Wall ◽  
Braced Frame ◽  
Moment Resisting Frame ◽  
Rigid Frame ◽  
Base Isolator ◽  
Non Linear ◽  
Moment Resisting ◽  
Performance Based Seismic Design

Bangunan yang hancur oleh gempa dapat dicegah dengan memperkuat struktur bangunan terhadap gaya gempa yang bekerja padanya. Perkuatan bangunan dapat dilakukan dengan memperkaku bangunan dalam arah lateral yaitu <em>moment resisting frame</em> (<em>rigid frame</em>), <em>braced frame</em> dan <em>shear wall</em>. Bangunan dinding geser merupakan salah satu jenis <em>bangunan</em> tahan gempa gedung beton bertulang menggunakan sistem rangka struktur yang dikombinasikan. Kinerja gedung akan bertambah dan menjadi optimal jika pola penempatan <em>dinding geser</em> serta metode analisanya tepat. Sistem lainnya dalam mengurangi kerusakan bangunan akibat gempa dengan <em>performance based seismic design</em> yaitu dengan menggunakan <em>base isolator.</em>, yang memanfaatkan teknik analisa non-linear berbasis komputer untuk menganalisa perilaku inelastis struktur dari berbagai macam intensitas gerakan tanah (<em>gempa</em>), sehingga dapat diketahui kinerjanya pada kondisi kritis. Tujuan penelitian ini dilakukan untuk mengetahui perioda dalam penggunaan <em>base isolator </em>dengan yang tanpa menggunakan <em>base isolator,</em> pada bangunan sistem ganda, lantai 10 tingkat, bentuk beraturan pada bangunan dinding geser. Analisis data yang dilakukan dengan menggunakan bantuan <em>software </em>komputer <em>SAP2000</em>. Pembebanan pada gedung didasarkan pada peraturan bangunan gedung beton bertulang dan analisa dinamik <em>Time History Modal Analysi</em>s struktur dalam Tata Cara Perencanaan Ketahanan Gempa Untuk Struktur Bangunan Gedung Dan Non Gedung (SNI 1726:2012). Dari hasil penelitian ini dapat diketahui bahwa penggunaan <em>base isolator</em> memperbesar perioda alami. Nilai perioda pada dinding geser dan dinding geser <em>base isolator</em> besarnya berturut-turut 0.988 detik dan 2.465 detik. Hal ini menyebabkan gaya gempa yang bekerja menjadi lebih kecil.

scholarly journals A Multiobjective Perspective to Optimal Sensor Placement by Using a Decomposition-Based Evolutionary Algorithm in Structural Health Monitoring

2020 ◽  
Vol 10 (21) ◽  
pp. 7710
Author(s):  
Tsung-Yueh Lin ◽  
Jin Tao ◽  
Hsin-Haou Huang
Keyword(s):  
Structural Health Monitoring ◽  
Evolutionary Algorithm ◽  
Health Monitoring ◽  
Sensor Placement ◽  
Frame Structure ◽  
Mode Shapes ◽  
Beam Model ◽  
Optimal Sensor Placement ◽  
Modal Assurance Criterion ◽  
Structural Health

The objective of optimal sensor placement in a dynamic system is to obtain a sensor layout that provides as much information as possible for structural health monitoring (SHM). Whereas most studies use only one modal assurance criterion for SHM, this work considers two additional metrics, signal redundancy and noise ratio, combining into three optimization objectives: Linear independence of mode shapes, dynamic information redundancy, and vibration response signal strength. A modified multiobjective evolutionary algorithm was combined with particle swarm optimization to explore the optimal solution sets. In the final determination, a multiobjective decision-making (MODM) strategy based on distance measurement was used to optimize the aforementioned objectives. We applied it to a reduced finite-element beam model of a reference building and compared it with other selection methods. The results indicated that MODM suitably balanced the objective functions and outperformed the compared methods. We further constructed a three-story frame structure for experimentally validating the effectiveness of the proposed algorithm. The results indicated that complete structural modal information can be effectively obtained by applying the MODM approach to identify sensor locations.

scholarly journals Comparison of Scaling Ground Motions Using Arithmetic with Logarithm Values for Spectral Matching Procedure

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Rui Zhang ◽  
Dong-sheng Wang ◽  
Xiao-yu Chen ◽  
Hong-nan Li
Keyword(s):  
Ground Motions ◽  
Time History ◽  
Response Spectra ◽  
Time History Analysis ◽  
Spectral Matching ◽  
Moment Resisting Frame ◽  
History Analysis ◽  
Moment Resisting ◽  
Structural Responses ◽  
Structural Time

In recent studies, spectral matching is the most commonly proposed method for selecting earthquake records for time-history analysis of structures. However, until now, there have been no serious investigations of the effects of coordinate values on the scaling of ground motions. This paper investigated the influence of using arithmetic and logarithmic values of response spectra in spectral matching procedures (i.e., ASM and LSM methods) on the results of nonlinear structural time-history analysis. Steel moment resisting frame structures of the 3-, 9-, and 20-stories, which represent low-, medium-, and high-rise buildings, respectively, were used as examples. Structural benchmark responses were determined by calculating the arithmetic mean and median of peak interstory drift ratio (PIDR) demands based on the three record sets developed by the American SAC Steel Project. The three record sets represent seismic hazard levels with 50%, 10%, and 2% probabilities exceeded in 50 years, and their average acceleration spectra were also taken as the target spectrum. Moreover, another 40 record components for selection were scaled both by ASM and LSM methods. The seven components whose spectra were best compatible with the target spectra were selected for the structural time-history analysis. The scale factors obtained by the LSM method are nearly larger than that of the ASM method, and their ranking and selection of records are different. The estimation accuracies of structural mean (median) responses by both methods can be controlled within an engineering acceptable range (±20%), but the LSM method may cause larger structural responses than the ASM method. The LSM method has a better capacity for reducing the variability of structural responses than the ASM method, and this advantage is more significant for longer-period structures (e.g., 20-story structure) with more severe nonlinear responses.

A comparative study of floor accelerations of different structural systems with lead-rubber-bearing (LRB) isolators

2020 ◽  
Author(s):  
Ali Ruzi Özuygur
Keyword(s):  
Base Isolation ◽  
Damping Ratio ◽  
Dual System ◽  
Base Shear ◽  
Nonstructural Components ◽  
Moment Resisting Frame ◽  
Lead Rubber Bearing ◽  
Moment Resisting ◽  
Seismic Base Isolation ◽  
Floor Acceleration

Seismic base isolation has been successfully used to protect structural and nonstructural components from the damaging effects of earthquakes by reducing floor accelerations and inter-story drifts for decades. The level of floor acceleration is a key issue in the protection of acceleration-sensitive nonstructural components. In this paper, floor acceleration performance of seismically isolated buildings with different lateral load resisting systems such as moment resisting frame, dual system, moment resisting frame plus viscous wall dampers and dual system plus viscous wall dampers is investigated. Moreover, the effectiveness of supplemental viscous damping devices equipped in parallel with lead-rubber isolators is studied. It is inferred from the study that the most effective way of reducing floor accelerations is to provide more rigidity to the superstructure. Utilizing supplemental viscous dampers along with lead-rubber isolators having about 20% of effective damping ratio is meaningless or harmful in relation to floor acceleration and base shear.

scholarly journals EVALUASI JARAK AMAN ANTARA STRUKTUR SRPM TINGGI DENGAN STRUKTUR SRPM DISEBELAHNYA TERHADAP GEMPA

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Ade Faisal ◽  
Tondi Amirsyah Putera ◽  
Mariden Purba
Keyword(s):  
Time History ◽  
Tall Buildings ◽  
Soil Conditions ◽  
Safe Distance ◽  
High Rise ◽  
Moment Resisting Frame ◽  
History Analysis ◽  
Moment Resisting ◽  
Dynamic Time ◽  
Storey Building

Pembangunan gedung-gedung tinggi menjadi salah satu alternatif yang di pilih karena keterbatasan dan mahalnya lahan diperkotaan sementara tingkat permintaan ruang untuk berbagai kegiatan semakin tinggi. Hal ini menyebabkan gedung-gedung bertingkat sering dibangun saling berdekatan satu dengan yang lainnya. Benturan dapat terjadi pada dua bangunan gedung bertingkat yang bersebelahan apabila jarak antara dua bangunan lebih kecil dari simpangan maksimum yang terjadi akibat beban gempa. Studi ini bertujuan untuk mencari jarak aman antara dua bangunan tinggi yang bersebelahan. Gedung yang direncanakan 2 model menggunakan SRPM dengan material beton bertulang yang terletak di kota Medan dengan kondisi tanah sedang. Model  pertama (Model 1) direncanakan memiliki tinggi 28,5 meter terdiri dari 8 lantai, sedangkan Model kedua (Model 2) direncanakan memiliki tinggi 35,5 meter terdiri dari 10 lantai. Analisa yang digunakan pada studi ini yaitu analisis dinamik riwayat waktu. Nilai simpangan yang terjadi pada gedung  8 lantai (Model 1) untuk arah x sebesar 80,87 mm dan untuk arah y sebesar 79,35 mm. Simpangan yang  terjadi pada gedung 10 lantai (Model 2) untuk arah x sebesar 113,33 mm dan untuk arah y sebesar 112,39 mm. Hasil analisa yang dilakukan menunjukkan jarak aman antara gedung 8 lantai dengan gedung 10 lantai adalah sebesar 2,1 meter, sedangkan jarak aman antara gedung 10 lantai dengan gedung 10 lantai adalah sebesar 2,2 meter.  Kata Kunci : Analisis Riwayat Waktu, Benturan Antar Gedung, Jarak Antar Gedung, Simpangan  ABSTRACT The construction of tall buildings became one of alternative that was chosen because of the urban land limitations and the cost. At the same time the space demand for various urban activities is increased. It is caused the high-rise buildings are often built very close to one another. The collision can be occurred if two adjacent building if the distance between the two building is smaller than the maximum drift caused by the earthquake action. This study aims to plan a safe distance between two adjacent high-rise buildings. The planned building two models using Moment Resisting Frame with reinforced concrete material that is located in the city Medan with moderate soil conditions. The first model (Model 1) has a height of 28.5 meters is planned consists of 8 floors, while the second model (Model 2) planned to have a height of 35.5 meters consists of 10 floors. The analysis used in this study is the analysis of dynamic time history. The displacement value which occurred on 8 storey building (Model 1) to the x direction by 80.87 mm and for the y direction by 79.35 mm. The displacement occurs in the building 10 floors (Model 2) to the x direction of 113.33 mm and for the y direction of 112.39 mm. The results of analysis indicate that the safe distance between 8 storey building with 10 floors of the building is 2.1 meters, while the safe distance between buildings 10 floors with 10 storey building is 2.2 meters. Keywords: Time History Analysis, Clash Between Buildings, Distance Between Buildings, Deviation

Numerical implementation of variable friction sliding base isolators and preliminary experimental results

2020 ◽  
Vol 36 (2) ◽  
pp. 767-787
Author(s):  
Tianye Yang ◽  
Paolo M Calvi ◽  
Richard Wiebe
Keyword(s):  
Base Isolation ◽  
Numerical Study ◽  
Three Dimensional ◽  
Structural Response ◽  
Time History ◽  
Experimental Results ◽  
Vertical Coupling ◽  
Moment Resisting ◽  
Variable Friction ◽  
Nonlinear Time History

The development of variable friction base isolation systems (VFSs) is the object of an ongoing international research project that involves extensive numerical and experimental activities. This article presents some of the recent numerical developments carried out as part of this project. More specifically, a three-dimensional (3D) variable friction (VF) element is formulated and implemented into OpenSees, providing the foundation for studying structural response in the context of nonlinear time history (NLTH) analysis. The element implementation captures the bearing bidirectional horizontal response along with horizontal–vertical coupling effects. Response predictions obtained using this newly implemented element are compared with the experimental results obtained from testing a full-scale VFS prototype, showing promising results. Finally, a demonstrative numerical study is carried out in which a steel moment resisting frame (MRF) structure, isolated using VFSs, is analyzed via NLTH analyses.

Optimal Sensor Placement Based on Tabu Search Algorithms

2014 ◽  
Vol 578-579 ◽  
pp. 1069-1072 ◽  
Author(s):  
Jie Zi Zhan ◽  
Ling Yu
Keyword(s):  
Tabu Search ◽  
Sensor Placement ◽  
Least Mean Square ◽  
Optimal Sensor Placement ◽  
Modal Assurance Criterion ◽  
Mean Values ◽  
Moving Force ◽  
Matrix Condition Number ◽  
The Mean ◽  
Matrix Condition

In this study, the Tabu search (TS) algorithm is introduced into the optimal sensor placement (OSP) problem in the field of the structural health monitoring and moving force identification. A TS-based OSP procedure is proposed and further evaluated by some numerical simulations on a 2D planar truss model. The mean values of off-diagonal elements in a modal assurance criterion (MAC) matrix are used as the optimization objective function. Based on the criteria of MAC, determinant of fisher matrix, matrix condition number, and the least mean square error, the TS-based OSP procedure is evaluated through comparing with ones due to both of the energy coefficient-effective independence (ECEFI) and the effective independence (EFI) algorithms. The results show that the proposed TS-based OSP procedure is feasible with a higher accuracy.

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