Download or read book Finite element Based Damage Detection Methods for Nonlinear Reinforced Concrete Structures written by Ai-Lun Wu and published by . This book was released on 2012 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: An objective of the structural health monitoring system is to identify the state of the structure and to detect its damages after a major event, such as a strong earthquake. The ability to assess the state of the structure, including its damages, immediately after a severe event, will allow a rapid assessment of the civil infrastructures for the post-event emergency responses, rescues and management, to guarantee the safety operations of these structures. Hence, intensive research has been conducted for detecting structural damages based on vibration data measured from sensors. To date, unfortunately, practical and effective damage identification techniques based on the finite-element formulation remain to be developed for large-scale linear and nonlinear structures, in particular nonlinear hysteretic reinforced concrete (RC) structures. The objective of this research is to develop an innovative, practical and efficient identification method based on the finite-element formulation, system condensation technique, and the event response data, such as the seismic response data, for applications to structural health monitoring systems. The innovative research will be capable of quantitatively determining the damage severity (time varying stiffness degradations) and locations of damages at element level. The developed new and efficient finite-element based methodology for structural damage detection would be: (1) applicable to linear and non-linear structures. (2) capable of identifying and tracking the structural damages using a minimum number of sensors, (3) capable of detecting local damages at element level, and (4) ready for practical applications to the health monitoring of complex structures. In addition to the theoretical/numerical development, experimental test data using large-scale linear and nonlinear structures, i.e. 1/3-scaled two-story RC frame and 1/2-scaled one-story two-bay RC frame, obtained from the National Center for Research on Earthquake Engineering (NCREE), Taiwan, will be used to verify the proposed innovative structural damage detection technique.

Download or read book Local Damage Detection of Nonlinear Structures Based on a Model of Finite length Plastic Regions written by Saeed Jolghazi and published by . This book was released on 2013 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a practical method to identify the damage in nonlinear structures, particularly reinforced concrete (RC) frames, is a challenging problem. In this dissertation, a practical method of local damage detection for nonlinear structures, based on the finite element formulation and the adaptive quadratic sum-square error with unknown inputs (AQSSE-UI) technique, is presented. In this study, the nonlinear structure is represented by the finite element formulation with finite-length plastic regions at the ends of each element. The modified Takeda model is used to characterize the hysteretic behavior of the plastic regions. The modified Takeda model is used because it involves less unknown parameters to be identified. Then, the number of degrees of freedom of the finite-element formulation is reduced using the static condensation method. The adaptive quadratic sum-square error with unknown inputs (AQSSE-UI) technique recently developed is used to identify the unknown structural parameters, thereby the stiffness degradation, the strength degradation, and the pinching effect of nonlinear RC structures can be detected. The performance of the proposed method of the local damage detection is verified by the shake table experimental tests using a 1/3-scale 2-story RC frame and three identical 1/2-scale 1-story 2-bay RC frames conducted at the National Center for Research on Earthquake Engineering (NCREE), Taiwan. Experimental results demonstrate that the proposed damage detection method is capable of: (i) identifying the unknown structural parameters using a minimum number of sensors, and (ii) tracking the stiffness and strength degradations as well as the pinching effect of nonlinear structures.

Download or read book Deep Learning Applications Volume 2 written by M. Arif Wani and published by Springer. This book was released on 2020-12-14 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected papers from the 18th IEEE International Conference on Machine Learning and Applications (IEEE ICMLA 2019). It focuses on deep learning networks and their application in domains such as healthcare, security and threat detection, fault diagnosis and accident analysis, and robotic control in industrial environments, and highlights novel ways of using deep neural networks to solve real-world problems. Also offering insights into deep learning architectures and algorithms, it is an essential reference guide for academic researchers, professionals, software engineers in industry, and innovative product developers.

Download or read book Nonlinear Finite Element Model Updating for Nonlinear System and Damage Identification of Civil Structures written by Hamed Ebrahimian and published by . This book was released on 2015 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural health monitoring (SHM) is defined as the capability to monitor the performance behavior of civil infrastructure systems as well as to detect, localize, and quantify damage in these systems. SHM technologies contribute to enhance the resilience of civil infrastructures, which are vulnerable to structural aging, degradation, and deterioration and to extreme events due to natural and man-made hazards. Given the limited financial resources available to renovate or replace them, it is crucial to implement SHM methodologies, which can help detect safety threats at an early stage, evaluate the operational risk of the infrastructure after a catastrophic event, and prioritize the urgency of the repair/retrofit or replacement of these structures. This research focuses on the development of a novel framework for nonlinear structural system identification. This framework consists of updating mechanics-based nonlinear finite element (FE) structural models using Bayesian inference methods. Recognizing structural damage as the manifestation of structural material nonlinearity, the developed framework provides a new methodology for post-disaster SHM and DID of real-world civil structures. This research is subdivided in two parts. The first part investigates the accuracy of state-of-the-art nonlinear FE modeling in predicting the cyclic and dynamic inelastic response behavior of reinforced concrete structural components and systems. Sources of inaccuracy and uncertainty in the FE modeling and simulation approach are investigated by comparing the FE-predicted structural response with high-fidelity experimental results. In the second part of this research, two frameworks for nonlinear FE model updating are proposed, developed, and validated using numerically simulated data. In the proposed frameworks, different Bayesian estimation methods are utilized to update the nonlinear FE model of a civil structure using the recorded input excitation and response of the structure during a damage-inducing earthquake event. The initial frameworks are then extended to output-only nonlinear structural system and damage identification methods. This extension not only overcomes the shortcomings of the initial frameworks in handling unmeasured or noisy input measurements, but also paves the way to a general approach to account for model uncertainties. Finally, a new information-theoretic approach is developed for the purposes of nonlinear FE model identifiability, experimental design, and optimal sensor placement.

Download or read book Dynamic Methods for Damage Detection in Structures written by Antonino Morassi and published by Springer Science & Business Media. This book was released on 2008-12-11 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non destructive testing aimed at monitoring, structural identification and di- nostics is of strategic importance in many branches of civil and mechanical - gineering. This type of tests is widely practiced and directly affects topical issues regarding the design of new buildings and the repair and monitoring of existing ones. The load bearing capacity of a structure can now be evaluated using well established mechanical modelling methods aided by computing facilities of great capability. However, to ensure reliable results, models must be calibrated with - curate information on the characteristics of materials and structural components. To this end, non destructive techniques are a useful tool from several points of view. Particularly, by measuring structural response, they provide guidance on the validation of structural descriptions or of the mathematical models of material behaviour. Diagnostic engineering is a crucial area for the application of non destructive testing methods. Repeated tests over time can indicate the emergence of p- sible damage occurring during the structure's lifetime and provide quantitative estimates of the level of residual safety.

Download or read book Vibration based Techniques For Damage Detection And Localization In Engineering Structures written by Ali Salehzadeh Nobari and published by World Scientific. This book was released on 2018-05-04 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the oil and gas industries, large companies are endeavoring to find and utilize efficient structural health monitoring methods in order to reduce maintenance costs and time. Through an examination of the vibration-based techniques, this title addresses theoretical, computational and experimental methods used within this trend.By providing comprehensive and up-to-date coverage of established and emerging processes, this book enables the reader to draw their own conclusions about the field of vibration-controlled damage detection in comparison with other available techniques. The chapters offer a balance between laboratory and practical applications, in addition to detailed case studies, strengths and weakness are drawn from a broad spectrum of information.

Download or read book System Identification and Damage Detection of Nonlinear Structures written by Ye Xia and published by . This book was released on 2011 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many civil and mechanical engineering structures exhibit nonlinear hysteretic behavior when subject to dynamic loads. The modeling and identification of non-linear hysteretic systems with stiffness and strength degradations is a practical but challenging problem encountered in the engineering field. Time domain analysis techniques, including the least square estimation (LSE) and the extended Kalman filter (EKF), have been used for the identification of structural parameters. However, the LSE approach may require the displacement measurements which are usually not measured in practice. With only the measurements of acceleration responses, the on-line system identification and damage detection is possible based on the EKF approach. However, for the EKF approach, the solutions may easily become unstable and may not converge. Furthermore, system identification approaches, such as LSE and EKF approaches, are usually more suitable for simple structures. For the finite element model (FEM) of a complex structure with a large number of degree-of-freedom (DOFs), it may require a large number of sensors and involve a heavy computational effort for the identification of structural damages. To overcome such a challenge, we propose the application of a reduced-order finite element model in conjunction with a recently proposed damage detection technique, referred to as the adaptive quadratic sum-square error with unknown inputs (AQSSE-UI). The identification process is divided into two steps. In the first step, static condensation technique is used to reduce the order of the equations of motion of the finite-element model. In the second step, the adaptive quadratic sum-square error with unknown inputs (AQSSE-UI) is used for the on-line system identification and damage detection of the reduced order system. The proposed approach is capable of identifying time-varying parameters of linear or nonlinear hysteresis structures. The capability of the proposed damage detection technique is demonstrated by shake table test data using large-scale structures. A 1/3-scaled 6-story steel frame, a 1/3-scaled 2-story RC frame and a 1/2-scaled one-story two-bay RC frame have been tested experimentally on the shake table at NCREE (The National Center for Research on Earthquake Engineering), Taiwan. For the 1/3-scaled 6-story steel frame structure, the damages of the joints were simulated by loosening the connection bolts. The 1/3-scaled 2-story RC frame was subject to a sequence of earthquake excitations back to back. Both RC frames are modeled by a series of finite elements and plastic hinges following the generalized Bouc-Wen model. Experimental results demonstrate that the proposed damage detection technique is quite accurate and effective for the tracking of: (i) the stiffness degradation of linear structures, and (ii) the non-linear hysteretic parameters with stiffness and strength degradations.

Download or read book Damage Detection of Structures Using Interval Finite Element Method written by Shyamala Venkitaraman and published by . This book was released on 2012 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Model Validation and Uncertainty Quantification Volume 3 written by Robert Barthorpe and published by Springer. This book was released on 2019-05-30 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model Validation and Uncertainty Quantification, Volume 3: Proceedings of the 37th IMAC, A Conference and Exposition on Structural Dynamics, 2019, the third volume of eight from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Model Validation and Uncertainty Quantification, including papers on: Inverse Problems and Uncertainty Quantification Controlling Uncertainty Validation of Models for Operating Environments Model Validation & Uncertainty Quantification: Decision Making Uncertainty Quantification in Structural Dynamics Uncertainty in Early Stage Design Computational and Uncertainty Quantification Tools

Download or read book System Identification and Damage Detection of Nonlinear Structures written by Ye Xia and published by LAP Lambert Academic Publishing. This book was released on 2012-04 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many civil and mechanical engineering structures exhibit nonlinear hysteretic behavior when subject to dynamic loads. The modeling and identification of non-linear hysteretic systems is a practical but challenging problem encountered in the engineering field. To overcome such a challenge, this book proposes the application of a reduced-order finite element model in conjunction with a recently proposed damage detection technique, referred to as the adaptive quadratic sum-square error with unknown inputs (AQSSE-UI). The identification process is divided into two steps: 1) static condensation technique is used to reduce the order of the equations of motion of the finite-element model; 2) AQSSE-UI is used for the on-line system identification and damage detection of the reduced order system. The proposed approach is capable of identifying time-varying parameters of linear or nonlinear hysteresis structures. The capability of the proposed damage detection technique is demonstrated by shake table test on three large-scale structures at NCREE, Taiwan.

Download or read book Proceedings of EcoComfort 2024 written by Zinoviy Blikharskyy and published by Springer Nature. This book was released on with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the 7th International Conference on Geotechnics Civil Engineering and Structures CIGOS 2024 4 5 April Ho Chi Minh City Vietnam written by Cuong Ha-Minh and published by Springer Nature. This book was released on with total page 1604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Overview of Modal based Damage Identification Methods written by and published by . This book was released on 1997 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper provides an overview of methods that examine changes in measured vibration response to detect, locate, and characterize damage in structural and mechanical systems. The basic idea behind this technology is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Therefore, changes in the physical properties will cause detectable changes in the modal properties. The motivation for the development of this technology is first provided. The methods are then categorized according to various criteria such as the level of damage detection provided, model-based vs. non-model-based methods and linear vs. nonlinear methods. This overview is limited to methods that can be adapted to a wide range of structures (i.e., are not dependent on a particular assumed model form for the system such as beam-bending behavior and methods and that are not based on updating finite element models). Next, the methods are described in general terms including difficulties associated with their implementation and their fidelity. Past, current and future-planned applications of this technology to actual engineering systems are summarized. The paper concludes with a discussion of critical issues for future research in the area of modal-based damage identification.

Download or read book ICCS19 19th International Conference on Composite Structures written by Antonio J.M. Ferreira and published by Società Editrice Esculapio. This book was released on 2016-08-01 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, it is quite easy to see various applications of fibrous composites, functionally graded materials, laminated composite, nano-structured reinforcement, morphing composites, in many engineering fields, such as aerospace, mechanical, naval and civil engineering. The increase in the use of composite structures in different engineering practices justify the present international meeting where researches from every part of the globe can share and discuss the recent advancements regarding the use of standard structural components within advanced applications such as buckling, vibrations, repair, reinforcements, concrete, composite laminated materials and more recent metamaterials. For this reason, the establishment of this 19th edition of International Conference on Composite Structures has appeared appropriate to continue what has been begun during the previous editions. ICCS wants to be an occasion for many researchers from each part of the globe to meet and discuss about the recent advancements regarding the use of composite structures, sandwich panels, nanotechnology, bio-composites, delamination and fracture, experimental methods, manufacturing and other countless topics that have filled many sessions during this conference. As a proof of this event, which has taken place in Porto (Portugal), selected plenary and keynote lectures have been collected in the present book.

Download or read book Detection of Non symmetrical Damage in Smart Plate like Structures written by Harvey Thomas Banks and published by . This book was released on 1998 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Damage Mechanics with Finite Elements written by P.I. Kattan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major goal of this book is to present the implementation of some damage models with finite elements. The damage models are based on the principles of continuum damage mechanics and the effective stress concept. Several books have appeared recently on damage mechanics but are mostly theoretical in nature. Alternatively, this book provides a complete finite element program that includes the effects of damage. The book consists of two parts. Part I includes two chapters mainly review ing topics from finite element analysis and continuum damage mechanics. The reader is cautioned that the material contained in this part is introductor- other references must be consulted for the theoretical aspects of these topics. For a complete theoretical treatment of the subject, the reader is referred to the book Advances in Damage Mechanics: Metals and Metal Matrix Composites by Voyiadjis and Kattan, published in 1999. In Part II the finite element program DNA is introduced in three chapters. DNA stands for "Da mage Nonlinear Analysis". The program can be used for the analysis of elasto plastic material behavior including the effects of damage within the frame work of damage mechanics. Two versions of DNA are presented - one for small strain analysis and one for finite strain analysis. The program makes extensive calls to a library of tensor operations developed by the authors. The tensor library is extensively outlined in the last chapter of the book.

Download or read book Mechanics of Structures and Materials XXIV written by Hong Hao and published by CRC Press. This book was released on 2019-08-08 with total page 1966 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanics of Structures and Materials: Advancements and Challenges is a collection of peer-reviewed papers presented at the 24th Australasian Conference on the Mechanics of Structures and Materials (ACMSM24, Curtin University, Perth, Western Australia, 6-9 December 2016). The contributions from academics, researchers and practising engineers from Australasian, Asia-pacific region and around the world, cover a wide range of topics, including: • Structural mechanics • Computational mechanics • Reinforced and prestressed concrete structures • Steel structures • Composite structures • Civil engineering materials • Fire engineering • Coastal and offshore structures • Dynamic analysis of structures • Structural health monitoring and damage identification • Structural reliability analysis and design • Structural optimization • Fracture and damage mechanics • Soil mechanics and foundation engineering • Pavement materials and technology • Shock and impact loading • Earthquake loading • Traffic and other man-made loadings • Wave and wind loading • Thermal effects • Design codes Mechanics of Structures and Materials: Advancements and Challenges will be of interest to academics and professionals involved in Structural Engineering and Materials Science.