Author : Tarek Elkhoraibi
Publisher :
Page : 201 pages
File Size : 31,70 MB
Release : 2007
Category : Earthquake resistant construction
ISBN :
Author : Fardad Mokhtari Dizaji
Publisher :
Page : 0 pages
File Size : 43,30 MB
Release : 2022
Category : Earthquake engineering
ISBN :
Numerical simulation and hybrid simulation are extensively used in earthquake engineering to evaluate the seismic response of structures under seismic loading. Despite the advances in computing power and the development of efficient integration algorithms in the past, numerical simulation techniques suffer from a high computational cost and the uncertainty associated with the definition of constitutive material models, boundary conditions, and mesh density, in particular in highly nonlinear, large or complex structures. On the other hand, the results of hybrid simulation can become biased when only one or limited number of potential critical components, seismic fuses, are physically tested due to laboratory or cost constraints. The recent progress in machine learning algorithms and applications in engineering has motivated novel and innovative simulation techniques achieved by leveraging data in various fields of engineering including seismic engineering where complexities arising from the stochastic nature of the phenomenon can be tackled by making use of available experimental and numerical data towards the development of more reliable simulation models and dynamic analysis frameworks. Furthermore, to better exploit the potential of data-driven models, such models can efficiently be incorporated into the physics-based and experimental techniques, leading to improved seismic response assessment methods. This M.Sc. thesis proposes two new hybrid analysis frameworks by integrating emerging data-driven techniques into the conventional structural response assessment techniques, namely numerical simulation and hybrid testing, to perform the nonlinear structural analysis under seismic loading. The first framework, referred to as the hybrid data-driven and physics-based simulation (HyDPS) technique, combines the well-understood components of the structure modeled numerically with the critical components of the structure, e.g., seismic fuses, simulated using the proposed data-driven PI-SINDy model. The data-driven model is developed for steel buckling-restrained braces based on experimental data to mathematically estimate the underlying relationship between displacement history and restoring force. The second framework incorporates the data-driven model into the conventional seismic hybrid simulation framework where the experimental test data of one of the critical components (physical twin), e.g., steel buckling-restrained brace, produced during hybrid simulation can be used in real-time to predict the nonlinear cyclic response of the other critical components of the system (digital twins) that are not physically tested. This framework features a novel multi-element seismic hybrid simulation technique achieved by recursively updating the force-deformation response of the digital twin. The performance of the proposed data-driven hybrid analysis frameworks is verified using past experimental test data and nonlinear response history analyses performed under representative earthquake ground motion accelerations. The results reveal that integrating data-driven techniques into conventional seismic analysis methods, namely numerical simulation and hybrid simulation, yields a more efficient seismic simulation tool that can be used to examine the seismic response of structural systems.
Author : Riadh Al-Mahaidi
Publisher : Springer
Page : 92 pages
File Size : 33,27 MB
Release : 2017-09-04
Category : Science
ISBN : 9811058679
This book describes the multi-axis substructure testing (MAST) system, a simulator developed at Swinburne University of Technology, Australia, which provides state-of-the-art technology for large-scale hybrid testing of structures under realistic scenarios depicting extreme events. The book also demonstrates the responses of physical specimens while they serve as part of the virtual computer model of the full structure subjected to extreme dynamic forces. Experimental studies using the MAST system are expected to enhance design and construction methods and significantly improve the repair and retrofitting of structures endangered by natural disasters and man-made hazards, providing a direct benefit to society by improving public safety and the re silience of the built environment. An additional benefit is increased sustainability in the form of reduced direct and indirect economic losses and social and environmental impacts in the face of extreme events. This book will be of interest to researchers and advanced practitioners in the fields of structural earthquake engineering, geotechnical earthquake engineering, engineering seismology, and experimental dynamics, including seismic qualification.
Author :
Publisher :
Page : 234 pages
File Size : 29,79 MB
Release : 2007
Category :
ISBN :
Real Time Dynamic Hybrid Simulation (RTDHS) was first proposed for structural engineering to evaluate the seismic performance of structural systems/components by combining the physical test and numerical simulation. During a hybrid simulation, the whole structure under investigation is divided into two parts. The part being physically constructed and tested is considered as the experimental substructure. The physical test can be conduced using either shake tables or dynamic actuators or both of them depending on the researcher's interest. The rest part of the structure, named as the computational substructure, is numerically modeled and simulated so the dynamic effect on experimental substructure at the interface is determined and applied by physical loading systems. The RTDHS is a force-based method and includes the currently used seismic testing methods within a unified formulation developed in this dissertation. The hardware components necessary for RTDHS were integrated into a unified control platform, which includes Structural and Seismic Testing Controllers; Data Acquisition and Information Streaming and Real Time Hybrid Simulation Controllers. A framework to drive the RTDHS test was designed and implemented to fulfill the function, such as structure response simulations, interface force calculations and compensations necessary to synchronize all components as well as their imperfect performance. The test platform developed facilitates not only the local RTDHS test but addresses geographically distributed hybrid simulation as well. Its flexible architecture allows to make improvements without modifying the hardware infrastructure. While a number of tests were performed in medium scale, a small scale pilot setup including a one story shear model, an actuator and a one directional shake table were constructed for the proof-of-concept of the proposed unified control platform. A three story hybrid simulated structure was tested. Test results verify the concept of the proposed unified formulation in RTDHS and the feasibility of the corresponding operating platform.
Author : Wei Song
Publisher : Frontiers Media SA
Page : 213 pages
File Size : 30,75 MB
Release : 2021-01-13
Category : Technology & Engineering
ISBN : 2889663809
Author :
Publisher :
Page : 271 pages
File Size : 25,61 MB
Release : 2008
Category :
ISBN :
The increased need for experimental verification of the seismic performance of conventional and novel structural systems has resulted in highly sophisticated dynamic test procedures. Hybrid simulation, including pseudo-dynamic testing of experimental substructures, offers an efficient method for assessment of dynamic and rate-dependent behavior of large-scale structural systems subjected to earthquake excitation. Compared to earthquake simulations using shake tables, hybrid simulation may have significant advantages in terms of cost, scale, geometry, and required physical mass of structures and components that can be tested. However, recent hybrid simulations have been limited to simplified structural models with only a few degrees of freedom. This is primarily due to the fact that hybrid simulation is a relatively new test method that is still being improved through research. Currently, the major challenges for using hybrid simulation in large and complex structural systems are the lack of robust simulation algorithms, and the sensitivity of the results to experimental errors in the presence of high-frequency modes. The main motivation for this research is to develop reliable test procedures that can be easily applied to fast and real-time hybrid simulations of large and complex structural systems. It is also attempted to develop test procedures that are effective for geographically distributed hybrid simulations. In this dissertation, recent developments to improve the accuracy and stability of hybrid simulation are described using the state-of-the-art pseudo-dynamic hybrid simulation system at the Structural Engineering and Earthquake Simulation Laboratory, University at Buffalo. In particular, delay compensation procedures are examined, and new methods are proposed. These methods are based on the correction of tracking errors in force measurement signal, and using the numerical integration procedure for prediction and compensation of command displacement signal. A new online procedure is proposed for estimation of delay during the simulation, and is shown to have better performance compared to existing online delay estimation methods. Furthermore, two numerical integration procedures are introduced for hybrid simulation, which are shown to improve the stability and accuracy properties of the simulation. The proposed integration algorithms use experimental measurements to iterate within implicit scheme and also take advantage of a new approach to estimate the tangent stiffness matrix of experimental substructures. For assessment of the reliability of hybrid simulation results, energy-based error monitors are proposed to examine the severity of experimental and numerical errors. These measures are then used to demonstrate the improved accuracy offered by new algorithms proposed here through analytical and numerical studies, and numerical and experimental simulations.
Author : Syed Murtuza Abbas
Publisher :
Page : 474 pages
File Size : 23,47 MB
Release : 2015
Category :
ISBN :
Hybrid simulation technology is being widely used in the field of structural engineering for testing of structural systems to study their dynamic behavior under seismic loads. It involves coupling of experimental laboratory testing of complex parts of a system with computational models of the remaining parts of the system whose behavior can be simulated with confidence in a finite element program. A hybrid engine program helps the experimental and computational modules to interact with each other in real-time under seismic loading, and gives the overall response of the entire system as a whole. However, to conduct hybrid testing of even the simplest of systems, the number of experimental tests required exceed the capabilities of any laboratory in the country. All research in this field to date has been conducted either using highly simplified models, or by compromising the accuracy of the overall results by performing experimental testing of only a few most complex sub-structures of the structural system. The current project delivers an advanced hybrid simulation (AHS) model that removes the current limitations of hybrid simulation technology. It engages a single experimental module per type of sub-structure that is complex enough to require experimental testing, and predicts the hysteretic response of all similar sub-structures present in the entire structural system using phenomenology and artificial intelligence. This, coupled with the response of computational models of rest of the system at every increment, provides highly realistic and economical results by drastically cutting down the number of experimental tests required for hybrid testing. The present work removes the limitations of the existing phenomenological models and employs them to make the predictions. The AHS model is independent of material and geometry of the sub-structure, as it just requires inputs from the experimental response of a sub-structure at every load increment to predict the response of all similar sub-structures to any type of loading.
Author : Chelsea Griffith
Publisher :
Page : 144 pages
File Size : 21,14 MB
Release : 2012
Category : Structural engineering
ISBN :
Pseudodynamic hybrid simulation technique was developed to evaluate structural seismic performance by physically testing the critical portion with the remaining structure simulated using a numerical model in the computer. An incremental approach was adopted in developing the control scheme to suit multiple testing facilities and test specimens. First the small scale, predictable specimen was utilized to investigate techniques of improving stability, slowing down the loading rate and triggering the accurate force measurement in a series of at benchmark scale experiments in the Laboratory of Earthquake and Structural Simulation at Western Michigan University (WMU). A step/hold command scheme was developed and results matched well to those obtained from the purely numerical simulations of the analytical model setup based on the cyclic tests. Then a series of open and closed loop PSD hybrid simulations of increasing amplitude were conducted at large scale in the Structural Engineering Laboratory at University of Alabama. A ramp/hold displacement command scheme with flexible definition on the ramp phase were developed to the address the excessive vibrations due to the very high speed actuator. The final control scheme was applied the large scale PSD hybrid simulation of a two story wood frame building with a physical first story wood shear wall and numerical second story and reasonable seismic response were achieved. The results of this study serve as a basis for developing the simulation technique for the large scale hybrid simulation that that will be conducted at the NEES equipment site at the University of Buffalo.
Author : Vesna Terzic
Publisher :
Page : 224 pages
File Size : 12,65 MB
Release : 2010
Category : Bridges
ISBN :
The test results were then used to calibrate a finite element model of a bridge column. This bridge column model was incorporated into a hybrid model of a typical California overpass bridge and tested using the hybrid simulation technique. The finite element model of the typical California overpass bridge was validated using the data from hybrid simulations. The validated model of the typical bridge was used to evaluate its post-earthquake truck load capacity in an extensive parametric study that examined the effects of different ground motions and bridge modeling parameters such as the boundary conditions imposed by the bridge abutments, the location of the truck on the bridge, and the amount of bridge column residual drift. The principal outcomes of this study are the following findings.
Author : Victor Saouma
Publisher : CRC Press
Page : 242 pages
File Size : 10,60 MB
Release : 2014-04-21
Category : Computers
ISBN : 1482288613
Hybrid Simulation deals with a rapidly evolving technology combining computer simulation (typically finite element) and physical laboratory testing of two complementary substructures. It is a cost effective alternative to shaking table test, and allows for the improved understanding of complex coupled systems. Traditionally, numerical simulation an
