Ehsan Noroozinejad Farsangi | The University of British Columbia (original) (raw)

Research paper thumbnail of A Novel MRE Adaptive Seismic Isolator Using Curvelet Transform Identification

Applied Sciences, 2021

Magnetorheological elastomeric (MRE) material is a novel type of material that can adaptively cha... more Magnetorheological elastomeric (MRE) material is a novel type of material that can adaptively change the rheological property rapidly, continuously, and reversibly when subjected to real-time external magnetic field. These new type of MRE materials can be developed by employing various schemes, for instance by mixing carbon nanotubes or acetone contents during the curing process which produces functionalized multiwall carbon nanotubes (MWCNTs). In order to study the mechanical and magnetic effects of this material, for potential application in seismic isolation, in this paper, different mathematical models of magnetorheological elastomers are analyzed and modified based on the reported studies on traditional magnetorheological elastomer. In this regard, a new feature identification method, via utilizing curvelet analysis, is proposed to make a multi-scale constituent analysis and subsequently a comparison between magnetorheological elastomer nanocomposite and traditional magnetorheo...

Research paper thumbnail of A Critical Review on Control Strategies for Structural Vibration Control

In recent years, the application of structural control strategies to attenuate the dynamic respon... more In recent years, the application of structural control strategies to attenuate the dynamic response of civil engineering structures subjected to human-induced and environmental loads has once again received much attention. The hardware involved in providing effective control, the stochastic nature of the dynamic excitation, the number of distinct variables required to determine the dissipating forces, and the nature of the control approach are a few of the parameters involved in determining the efficacy of structural control systems. However, the primary parameter to determine the overall performance of a smart adaptive structure is the implementation of a control algorithm that would conveniently counteract the external known and/or unknown excitation by providing additional force input through control devices. The control algorithm to be adopted should be robust, multipurpose , and simple to design and implement. Moreover, the control algorithm should provide the flexibility in selecting performance objectives for a holistically effective response reduction. This paper focuses on providing a comprehensive review of control algorithms implemented in structural control engineering. This article first provides an overview of the fundamental concepts pertaining to the vibration control of structures subjected to dynamic excitations. Next, an exhaustive review of different types of control algorithms that feed the input signal to active-type control devices is conducted. Thereafter, important benchmark applications in the field of structural control in civil engineering are presented. Finally, conclusions are presented on the advantages and drawbacks of each control strategy and recommendations are presented for further research in this area.

Research paper thumbnail of Cyclic Behavior of Masonry Shear Walls Retrofitted with Engineered Cementitious Composite and Pseudoelastic Shape Memory Alloy

Sensors, 2022

The behavior of masonry shear walls reinforced with pseudoelastic Ni–Ti shape memory alloy (SMA) ... more The behavior of masonry shear walls reinforced with pseudoelastic Ni–Ti shape memory alloy (SMA) strips and engineered cementitious composite (ECC) sheets is the main focus of this paper. The walls were subjected to quasi-static cyclic in-plane loads and evaluated by using Abaqus. Eight cases of strengthening of masonry walls were investigated. Three masonry walls were strengthened with different thicknesses of ECC sheets using epoxy as adhesion, three walls were reinforced with different thicknesses of Ni–Ti strips in a cross form bonded to both the surfaces of the wall, and one was utilized as a reference wall without any reinforcing element. The final concept was a hybrid of strengthening methods in which the Ni–Ti strips were embedded in ECC sheets. The effect of mesh density on analytical outcomes is also discussed. A parameterized analysis was conducted to examine the influence of various variables such as the thickness of the Ni–Ti strips and that of ECC sheets. The results s...

Research paper thumbnail of A Data-Driven Approach for Linear and Nonlinear Damage Detection Using Variational Mode Decomposition and GARCH Model

ArXiv, 2022

In this article, an original data-driven approach is proposed to detect both linear and nonlinear... more In this article, an original data-driven approach is proposed to detect both linear and nonlinear damages in structures using output-only responses. The method deploys variational mode decomposition (VMD) and generalized autoregressive conditional heteroscedasticity (GARCH) model for signal processing and feature extraction. To this end, VMD decomposes the responsesignals are first decomposed to intrinsic mode functions (IMFs), and then, GARCH model is utilized to represent the statistics of IMFs. The model coefficients’ of IMFs construct the primary feature vector. Kernel-based principal component analysis (PCA) and linear discriminant analysis (LDA) are utilized to reduce the redundancy from the primary features by mapping them to the new feature space. The informative features are then fed separately into three supervised classifiers: support vector machine (SVM), k-nearest neighbor (kNN), and fine tree. The performance of the proposed method is evaluated on two experimental scal...

Research paper thumbnail of Seismic Fragility Estimation Under Orthogonal Earthquake Excitations

Estimation of fragility functions using dynamic structural analysis is an important step in a num... more Estimation of fragility functions using dynamic structural analysis is an important step in a number of seismic assessment procedures. This paper discusses the multicomponent seismic fragility curves based on beta distribution by considering the Iran–specific characteristics to manage the earthquake risk in the region. The seismic design of lowand mid-rise RC-MRFs are carried out according to the Iranian Code of Practice for Seismic Resistant Design of Buildings (Standard No. 2800), and the analytical models are formed accordingly in ZEUS-NL platform. A new optimal intensity measure (IM) called (Sa, avg) is used to obtain reliable fragility–based database for earthquake damage and loss estimation of RC buildings stock. It is observed that the presence of vertical component of the strong earthquake excitation significantly affects the response of RC-MRFs and including this component simultaneous to horizontal components in the analysis is highly recommended for reliable seismic asses...

Research paper thumbnail of A novel approach for deterioration and damage identification in building structures based on Stockwell-Transform and deep convolutional neural network

Journal of Structural Integrity and Maintenance, 2022

In this paper, a novel deterioration and damage identification procedure (DIP) is presented and a... more In this paper, a novel deterioration and damage identification procedure (DIP) is presented and applied to building models. The challenge associated with applications on these types of structures is related to the strong correlation of responses, which gets further complicated when coping with real ambient vibrations with high levels of noise. Thus, a DIP is designed utilizing low-cost ambient vibrations to analyze the acceleration responses using the Stockwell transform (ST) to generate spectrograms. Subsequently, the ST outputs become the input of two series of Convolutional Neural Networks (CNNs) established for identifying deterioration and damage to the building models. To the best of our knowledge, this is the first time that both damage and deterioration are evaluated on building models through a combination of ST and CNN with high accuracy.

Research paper thumbnail of Optimal design of Magnetorheological damper for seismic response reduction of Base-Isolated structures considering Soil-Structure interaction

Research paper thumbnail of Finite Element Modeling of Self-Compacting Concrete Beams Under Shear

Civil and Environmental Engineering Reports, 2021

Development of self-compacting concrete (SCC) is a very desirable achievement in the reinforced c... more Development of self-compacting concrete (SCC) is a very desirable achievement in the reinforced concrete (RC) structures for overcoming issues associated with many problems such as congestions of steel reinforcement. This non-vibrating concrete is not affected by the skill of workers, and the shape and amount of reinforcing bar arrangement of a structure. Due to the high fluidity and resisting power of reinforcing of SCC, it can be pumped longer distances. In this study, the finite element (FE) modeling of three SCC beams in shear while taking into account, the flexural tensile strength of concrete is computed and the results are compared with the available experimental tested reinforced SCC beams. The stirrups are located at 75 mm apart from the end of beams up to the loading point. The electrical strain gauges (ESGs) have been embedded on the stirrups and their strain readings are taken for every step of load increment. For modeling longitudinal steel reinforcing bars and concrete...

Research paper thumbnail of The effects of earthquake incidence angle on the seismic fragility of reinforced concrete box-girder bridges of unequal pier heights

Structure and Infrastructure Engineering, 2020

The effects of earthquake incidence angle on the seismic fragility of highway bridges of unequal ... more The effects of earthquake incidence angle on the seismic fragility of highway bridges of unequal pier heights are investigated. A variety of configurations from regular to so-called highly irregula...

Research paper thumbnail of A state-of-the-art review on the experimental investigations of bendable concrete

Journal of Building Pathology and Rehabilitation, 2021

Research paper thumbnail of Why Resilience-Based Design?

Reliability-Based Analysis and Design of Structures and Infrastructure, 2021

Research paper thumbnail of Influence of Pulse-Like Near-Fault Ground Motions on the Base-Isolated Buildings with LRB Devices

Practice Periodical on Structural Design and Construction, 2021

AbstractSeismic base isolation is a passive structural control system that has been effectively u... more AbstractSeismic base isolation is a passive structural control system that has been effectively utilized as an innovative seismic-resistant design method in the past decades. The properties of eart...

Research paper thumbnail of Effect of Foundation Flexibility on the Seismic Performance of a High-Rise Structure under Far-Field and Near-Field Earthquakes

International Journal of Engineering, 2021

In this study, the seismic performance of a 20-storey steel structure with a mat foundation locat... more In this study, the seismic performance of a 20-storey steel structure with a mat foundation located on layered soil is investigated under an array of strong ground excitations, which includes 6 far-fault and 6 near-fault earthquakes. Eight different modes for soil layering have been considered in the numerical simulation. FLAC 2D nonlinear platform has been used to model the near-realistic behavior. To this end, hundred lines of codes and subroutines have been developed in this platform to perform the analysis. The results of the analyzes include the absolute displacement of the floors, the ratio of the relative displacement of the floors, the shear force, the axial force, and the bending moment of the columns. It was concluded that for a 20-story structure on a mat foundation under both far-field and near-field earthquakes, the most reliable type of soil is the dense sandy soil and the most critical case is the soft clay soil. It was also observed that the near-field strong ground motions have imposed more critical structural responses compared to far-field records.

Research paper thumbnail of Response Control of Structures with Friction Dampers under Blast Loading

This study investigates the performance of the surface blast load acting on Moment Resistance Fra... more This study investigates the performance of the surface blast load acting on Moment Resistance Frames (MRF)with a novel slip load friction damper. Recently the world is facing terrorist activities that lead to the damage of the structures, including commercial, industrial, and public buildings. These structures should be protected by using control devices. Friction damper is a passive damping device that absorbs maximum energy released during vibrations. Blast loads are calculated based on empirical equations.In this study, single slip and double slip load friction dampers considering the hysteresis loops are used for controlling the response of the MRFs exposed to blast loadings. The four storey, eight storey, and twenty storey MRFs with surface blast responses are controlled by using single and double slip load friction dampers. The response includes displacement, accelerations, velocity, storey drift, storey drift ratio, pressure impulse curve, etc. The torsional effect with two d...

Research paper thumbnail of Development of risk-targeted seismic hazard maps for the Iranian plateau

Soil Dynamics and Earthquake Engineering, 2021

Relation prediction for knowledge graphs aims at predicting missing relationships between entitie... more Relation prediction for knowledge graphs aims at predicting missing relationships between entities. Despite the importance of inductive relation prediction, most previous works are limited to a transductive setting and cannot process previously unseen entities. The recent proposed subgraph-based relation reasoning models provided alternatives to predict links from the subgraph structure surrounding a candidate triplet inductively. However, we observe that these methods often neglect the directed nature of the extracted subgraph and weaken the role of relation information in the subgraph modeling. As a result, they fail to effectively handle the asymmetric/anti-symmetric triplets and produce insufficient embeddings for the target triplets. To this end, we introduce a Communicative Message Passing neural network for Inductive reLation rEasoning, CoMPILE, that reasons over local directed subgraph structures and has a vigorous inductive bias to process entity-independent semantic relations. In contrast to existing models, CoMPILE strengthens the message interactions between edges and entitles through a communicative kernel and enables a sufficient flow of relation information. Moreover, we demonstrate that CoMPILE can naturally handle asymmetric/anti-symmetric relations without the need for explosively increasing the number of model parameters by extracting the directed enclosing subgraphs. Extensive experiments show substantial performance gains in comparison to state-of-the-art methods on commonly used benchmark datasets with variant inductive settings.

Research paper thumbnail of Improved Vulnerability Index Methodology to Quantify Seismic Risk and Loss Assessment in Reinforced Concrete Buildings

Journal of Earthquake Engineering, 2021

An improved seismic vulnerability index methodology is formulated on the basis of eight modeled p... more An improved seismic vulnerability index methodology is formulated on the basis of eight modeled parameters that are designed according to earthquake-resistant design concept and derived from the em...

Research paper thumbnail of Deterioration and damage identification in building structures using a novel feature selection method

Structures, 2021

Abstract Identifying structural defects in complex structures is one of the main objectives in re... more Abstract Identifying structural defects in complex structures is one of the main objectives in real-world structural health monitoring (SHM) applications. In this article, a signal-based supervised methodology is proposed for detecting deterioration and damage in building structures. This method benefits from a novel feature selection method called signal simulation-based feature selection (SSFS) algorithm, which only relies on baseline signals to extract the most sensitive features from any type of structure. The results showed that the offered methodology is capable of identifying damage and deterioration precisely, and therefore, can be a viable alternative to conventional techniques that require additional information.

Research paper thumbnail of A Critical Review on Structural Health Monitoring: Definitions, Methods, and Perspectives

Archives of Computational Methods in Engineering, 2021

Research paper thumbnail of Investigation of proposed integrated control strategies based on performance and positioning of MR dampers on shaking table

Smart Materials and Structures, 2021

O conteúdo dos livros e seus dados em sua forma, correção e confiabilidade são de responsabilidad... more O conteúdo dos livros e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a

Research paper thumbnail of Simultaneous optimization approach for combined control–structural design versus the conventional sequential optimization method

Structural and Multidisciplinary Optimization, 2020

Although controller devices highly improve the seismic performance of civil structures, they usua... more Although controller devices highly improve the seismic performance of civil structures, they usually incur enormous financial costs. A variety of sequential methods for minimizing the cost function have been proposed in the literature. In most of these methods, the control system is optimally designed after the best structural configuration is provided. However, such sequential procedures are unable to yield the best overall design. This paper discusses a combined structural and control optimization approach in which the structural mass and controlled system energy are simultaneously minimized. To this end, a twofold objective function is defined by linearly combining the structural mass and linear quadratic regulator (LQR) performance index. It is shown that the optimal value of this objective function depends on the initial condition, and to circumvent this problem, an alternative objective function is introduced which allows for solving the problem of initial condition dependency. Given the complexity of the problem, a variable neighborhood search (VNS) metaheuristic method is developed. The performance of the developed method is demonstrated through case studies involving the determination of structural responses for shear-type frames. The case studies are presented for evaluating and comparing the effectiveness of the proposed simultaneous technique and the conventional sequential method. The responses of the structures are determined under an array of strong ground motions. The results of the comparative analyses revealed that the simultaneously optimized cases using the proposed methodology had superior dynamic performance compared to the sequentially optimized cases.