روش زمان دوام در ارزیابی لرزه‌ای پل‌های جداسازی‌شده مجهز به سیستم‌های کنترل فعال و نیمه‌فعال

نوع مقاله : مقاله کامل پژوهشی

نویسندگان

1 دانشکده مهندسی عمران، دانشگاه محقق اردبیلی

2 دانشکده مهندسی عمران، دانشگاه تبریز

3 دانشجوی دکتری، گروه مهندسی سازه، دانشگاه دانشگاه ناپل فدریکو دوم، ناپل، ایتالیا

چکیده

روش زمان دوام یک روش دینامیکی فزاینده است که از یک تابع فزاینده شتاب جهت تحلیل سازه استفاده می ­نماید. این روش با توجه به ماهیت دینامیکی آن می­تواند در طیف وسیعی از سازه­ ها، با هر نوع پلان و ارتفاع و هر تعداد درجه آزادی به ­کار رود. در این مطالعه روش زمان دوام جهت ارزیابی رفتار لرزه­ای پل جداسازی­ شده مجهز به انواع مختلف سیستم­ های کنترلی فعال و نیمه­ فعال، به­ کار گرفته شده است. برای بررسی توانمندی این روش در پیش­ بینی پاسخ­ های مدل مورد بررسی، نتایج آن با نتایج حاصل از تحلیل تاریخچه زمانی غیر خطی مجموعه­ ای از شتاب­ نگاشت­ های واقعی که طیف شتاب‌نگاشت‌های انتخاب ‌شده با استفاده از آنالیز موجک در حوزه زمان- فرکانس اصلاح و منطبق بر طیف پاسخ هدف می ­شود، مقایسه گردیده است. نتایج حاصل بیانگر آن است که روش زمان دوام پیش­ بینی مناسبی از رفتار سازه تحت سیستم ­های کنترلی مختلف، در اثر زلزله ­های واقعی ارائه می­ کند.

کلیدواژه‌ها


عنوان مقاله [English]

Endurance Time Method for Seismic Assessment of Isolated Bridges Equipped with Active and Semi Active Control Systems

نویسندگان [English]

  • Amin Gholizad 1
  • Javad Katebi 2
  • Arash Poursadrollah 3
  • Hamid Reza Nemati 2
1 Faculty of Civil Engineering, University of Mohaghegh Ardabili, Ardabil. Iran
2 Faculty of Civil Engineering, University of Tabriz, Iran
3 Department of Structures for Engineering and Architecture,University of Naples Federico II, Naples, Italy
چکیده [English]

The present study has been performed aiming to appraise the efficiency of endurance time method for evaluation of some vibration control methods in comparison with traditional time history dynamic analysis. Endurance Time method is a dynamic structural analysis that evaluates structural responses under different intensities. In this method structure is subjected to an intensifying predefined acceleration function and different damage indices of structure are evaluated through analysis time. The Endurance Time acceleration function have been generated for different spectra, such as ASCE07 design spectrum, in previous researches of ET group. Due to its inherent dynamic nature, there is no restriction on its application and it can be applied to any structure with any plan or height or any degree of freedoms. Furthermore, it can be used in linear or nonlinear analysis also it can significantly reduce computational demand compared to time history analysis. In this research the Endurance Time method has been applied to an isolated bridge with different control systems such as Active, Semi Active and Passive by using classical linear quadratic regulation (LQR) algorithm and Sliding Mode control (SMC). Two approaches including LQR and pole assignment method have been used for determination of sliding surface as an important parameter in SMC algorithm. The effectiveness and robustness of SMC and conventional LQR control to reduction in displacement response of the structure have been verified by different researchers. Viscous dampers with two different dissipation rate of  and have been considered as two passive control mechanisms. When these bridges are subjected to ground motion with large intensity, the deck displacement becomes excessively large so in this study, different control strategies are used to mitigate this phenomenon. Sliding Mode control with LQR approach has provided the best efficiency in dynamic response mitigation. Herein, the column-isolator-deck system has been idealized as two-degree-of-freedom lumped mass system. To evaluate its seismic behavior, a set of seven suitable records is selected and a wavelet-based procedure has been used to match their spectra with a target spectrum. These records are used for the comparison of the results of Endurance Time analysis with nonlinear time history analysis as a verified method. Results indicate that the Endurance Time method is capable of predicting the seismic behavior of isolated bridge with different control systems within acceptable accuracy. Considerable variance in the analyses result under ground motion records necessitates to apply numerous records to get reliable results while it is possible to attain close estimates using endurance time method. Although ground motion records and endurance time method both have resulted in similar trends for structural displacement response with different control approaches, results are more dispersed for different earthquake records with standard deviation of 1.2 up to 3.36 but this parameter decreases using endurance time method to 0.35 up to 1.58 and this method provides an accurate and time saver tool to evaluate the performance of structural vibration control methods under seismic excitations.

کلیدواژه‌ها [English]

  • Endurance Time method
  • Wavelet analysis
  • Isolated Bridge
  • Active and Semi-Active Control
ASCE Standard, “Minimum design load for building and other structures”, American Society of Civil Engineers, USA, 2005.
Chiniforush AA, Estekanchi H, Dolatshahi K, “Application of endurance time analysis in seismic evaluation of an unreinforced masonry monument”, Journal of Earthquake Engineering, 2016, 23, 827-884.
Estekanchi H, “Principle of structure design against seismic load”, Sharif Journal of Science and Technology, 1993, 15, 26-29.
Estekanchi H, Vafai A, Sadeghazar M, “Endurance time method for seismic analysis and design of structures”, Scientia Iranica Journal, 2004, 11 (4), 361-370.
Fayçal I, José R, “Systems with hysteresis analysis, identification and control using the Bouc-Wen model”, Wiley-Interscience, USA, 2007.
FEMA P695, “Quantification of building seismic performance factors”, APENDIX A (Ground Motion Record sets), Applied Technology Council, USA, 2009.
Franklin Y, Cheng H, Kangu L, “Smart structures innovative systems for seismic response control”, CRC Press, USA, 2008.
Hasani H, Golafshani AA, Estekanchi H, “Seismic performance evaluation of jacket type offshore platforms using endurance time method considering soil-pile-superstructure interaction”, Scientica Iranica Journal, 2017, 24, 1843-1854.
Lee TY, Chen PC, “Sliding mode control for nonlinear isolated bridges”, Journal of Earthquake Engineering, 2011, 15, 582-600.
Lilhanand K, Tseng WS, “Development and application of realistic earthquake time histories compatible with multiple damping response spectra”, Ninth World Conference on Earthquake Engineering, Tokyo, Japan, 1988, 2, 819-824.
Mukherjee S, Gupta VK, “Wavelet based generation of spectrum compatible time-histories”, Journal of Soil Dynamic Earthquake Engineering, 2002, 22, 799-804.
National Control for Earthquake Engineering, “Sliding mode control for seismic-excited linear and nonlinear civil engineering structures”, Technical Report, Prepared by Yang JN, Wu JC, Agrawal AK, Li Z, NCEER-94-0017, State University of New York, Buffalo, USA, 1994.
Pacific Earthquake Engineering Research Center, PEER Strong Motion Catalog, http://peer.berkeley.edu/smcat, 2000.
Soong TT, “Active structural control: theory and practice”, Longman structural engineering and structural mechanics series, England, 1990.
Symans MD, Constantinou MC, “Semi-Active control systems for seismic protection of structures: a state-of-the review”, Journal of Engineering Structures, 1999, 21, 469-487.
Utkin V I, “Sliding mode in control optimization”, Springer Verlag, New York, USA, 1992.
Vaezi D, Estekanchi H, Vafai A, “A parametric study of seismic response in anchored steel tanks with endurance time method”, Scientia Iranica Journal, 2014, 21 (5), 1608-1619.
Valamanesh V, “Investigation of Endurance Tie in Seismic Analysis of Steel Frames as Compared to Static Method”, MS. Thesis, Sharif University of Technology, Tehran, Iran, 2005.
Yang JN, Wu JC, Agrawal AK, Li Z, “Sliding mode control for nonlinear and hysteretic structures”, Journal of Engineering Mechanics, 1995, 121, 1330-1339.