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Wyniki wyszukiwania dla: MODIFICATION FACTORS, SEISMIC RETROFIT, SEISMIC COLLAPSE CAPACITY, FLUID VISCOUS DAMPERS, STRUCTURAL POUNDING
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Letter to the Editor: Discussion on the Paper “State-of-the-Art of Research on Seismic Pounding Between Buildings with Aligned Slabs”
PublikacjaThe paper “State-of-the-art of research on seismic pounding between buildings with aligned slabs” (by Kharazian and López-Almansa) has recently been published in the journal of Archives of Computational Methods in Engineering. It can be considered as a kind of continuation of previous ‘state-of-the-art’ publications, including two papers and a book. Unfortunately, the paper contains a number of misleading or wrong statements as...
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Seismic pounding between adjacent buildings: Identification of parameters, soil interaction issues and mitigation measures
PublikacjaStructural pounding has been observed in many previous earthquakes due to insufficient gap commonly provided between adjacent structures. The collisions usually generate large impact forces and short duration acceleration pulses which may result in significant damage to the colliding buildings. Because of that, earthquake induced structural pounding has been intensively studied and investigated for the last three decades. Results...
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Machine learning-based seismic fragility and seismic vulnerability assessment of reinforced concrete structures
PublikacjaMany studies have been performed to put quantifying uncertainties into the seismic risk assessment of reinforced concrete (RC) buildings. This paper provides a risk-assessment support tool for purpose of retrofitting and potential design strategies of RC buildings. Machine Learning (ML) algorithms were developed in Python software by innovative methods of hyperparameter optimization, such as halving search, grid search, random...
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Examples of retrofit of structures on seismic areas by friction pendulum system.
PublikacjaZastosowanie łożysk wahadłowych, w których dyssypacja energii następuje na skutek tarcia, to jedna z najbardziej obiecujących metod wzmacniania odporności sejsmicznej budowli. Celem artykułu jest przedstawienie przykładów zastosowania tej metody do różnych typów konstrukcji budowlanych narażonych na wstrząsy sejsmiczne.
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The response of three colliding models of steel towers to seismic excitation
PublikacjaA number of past and recent observations have confirmed that collisions between adjacent, insufficiently-separated structures occurring as a result of seismic excitation (structural pounding) may result in serious damage to structural elements and can even lead to their total destruction. This paper summarises the results obtained from a shaking table experimental study which investigated structural pounding between three adjacent...
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Reducing the seismic failure potential of reinforced concrete frames
PublikacjaNowadays, there is an extreme need for buildings with seismic resistance capability in rural areas, in which, it is possible to increase the floor number of buildings. In this study, the effects of number of bays and story levels on the seismic performance level of Reinforced Concrete (RC) frames were investigated. The 3-, 5-, 7-, and 9-story RC frames were modeled using ETABS software. In order to collapse state analysis, Incremental...
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Seismic Instruments
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Effect of Base-Connection Strength and Ductility on the Seismic Performance of Steel Moment-Resisting Frames
PublikacjaColumn-base connections in steel moment-resisting frames (SMFs) in seismic regions are commonly designed to develop the capacity of adjoining column with an intent to develop a plastic hinge in the column member, rather than in the connection (i.e., a strong-base design). Recent research has shown base connections to possess high ductility, indicating that this practice may be not only expensive but also unnecessary. This suggests...
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Machine learning-based prediction of seismic limit-state capacity of steel moment-resisting frames considering soil-structure interaction
PublikacjaRegarding the unpredictable and complex nature of seismic excitations, there is a need for vulnerability assessment of newly constructed or existing structures. Predicting the seismic limit-state capacity of steel Moment-Resisting Frames (MRFs) can help designers to have a preliminary estimation and improve their views about the seismic performance of the designed structure. This study improved data-driven decision techniques in...
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Seismic Response of High-Rise Buildings Equipped with Base Isolation and Non-Traditional Tuned Mass Dampers
PublikacjaOne of the methods in structural control is the application of combinational control systems in order to reduce the response of structures during earthquakes. The aim of the present paper is to verify the effectiveness of a hybrid control strategy, combining base isolation and non-traditional tuned mass dampers (TMDs) (i.e., TMDs with dashpots directly connected to the ground) in suppressing structural vibrations of high-rise buildings....
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Comparative analysis of seismic response reduction in multi-storey buildings equipped with base isolation and passive/active friction-tuned mass dampers
PublikacjaThis study presents an innovative approach to mitigating seismic responses in multi-storey buildings equipped with a base-isolation (BI) system and passive friction-tuned mass dampers (PFTMDs). The key innovation lies in the combined use of a BI system and a PFTMD system, as well as the activation of this mechanical system by controllers. Additionally, the research design optimizes the parameters of these devices specifically for...
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Machine learning-based seismic response and performance assessment of reinforced concrete buildings
PublikacjaComplexity and unpredictability nature of earthquakes makes them unique external loads that there is no unique formula used for the prediction of seismic responses. Hence, this research aims to implement the most well-known Machine Learning (ML) methods in Python software to propose a prediction model for seismic response and performance assessment of Reinforced Concrete Moment-Resisting Frames (RC MRFs). To prepare 92,400 data...
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Timber Frame Houses with Different Insulation Materials - Seismic Analysis
PublikacjaThe aim of this article is to present results of a dynamic numerical analysis focused on the response of two timber frame building structures exposed to seismic excitations. The first structure was insulated with mineral wool, while the second one with polyurethane foam. Specifications and technology involved in the models' construction are based on the previously conducted experimental study, upon which numerical structural models...
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Timber frame houses resistant to dynamic loads - seismic analysis
PublikacjaThe aim of the article is to present results of seismic analysis results of two real-sized timber frame buildings subjected to seismic excitations. The first model was insulated with mineral wool, the second one with polyurethane foam. Technology and specifications involved in both models construction is based on the previously conducted experimental research on timber frame houses, including wall panels tests, wall numerical models...
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Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
PublikacjaThe study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon...
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Experimental Study on Effectiveness of a Prototype Seismic Isolation System Made of Polymeric Bearings
PublikacjaSeismic isolation is identified as one of the most popular and effective methods of protecting structures under strong dynamic excitations. Base isolators, such as Lead Rubber Bearings, High Damping Rubber Bearings, and Friction Pendulum Bearings, are widely used in practice in many earthquake-prone regions of the world to mitigate structural vibrations, and therefore minimize loss of life and property damage during seismic events....
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Numerical study on seismic response of a base-isolated building modelled with shell elements
PublikacjaSeismic isolation is counted among the most popular and effective means of protecting structures against earthquake forces. Base isolators, like Lead-Rubber Bearings (LRB), High-Damping Rubber Bearings (HDB) or Friction Pendulum Systems (FPS) are extensively used in practice in many earthquake-prone regions of the world. The present paper reports the results obtained from the numerical study on seismic response of a base-isolated...
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JOURNAL OF SEISMIC EXPLORATION
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Shaking table experimental study on the effectiveness of polymer bearings for seismic isolation of structures
PublikacjaSeismic isolation has been recognised to be a very effective way of protecting structures from damage during earthquakes. It allows us to extend the natural period of the structure and therefore avoid resonance with the ground motion. Moreover, by increasing damping in the isolation devices, more energy can be dissipated and thus the structural response can be further reduced. The aim of this paper is to show the results of the...
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Assessment of codes recommendations for the evaluation of the seismic gap of buildings founded on different soil types
PublikacjaSeveral equations have been proposed in the literature to evaluate the seismic gap preventing earthquake-induced structural pounding, such as the ones based on the absolute sum of the peak displacements (ABS), the square root of the sum of the squares (SRSS), the double difference method (DDC), Australian code and the approach proposed by Naderpour et al. The aim of this paper is to investigate the accuracy of these equations taking...
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Advanced Hysteretic Model of a Prototype Seismic Isolation System Made of Polymeric Bearings
PublikacjaThe present paper reports the results of acomprehensive study designed to verify the effectiveness of an advanced mathematical model in simulating the complex mechanical behaviour of a prototype seismic isolation system made of polymeric bearings (PBs). Firstly, in order to construct the seismic bearings considered in this research, a specially prepared flexible polymeric material with increased damping properties was employed....
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Seismic response and performance prediction of steel buckling-restrained braced frames using machine-learning methods
PublikacjaNowadays, Buckling-Restrained Brace Frames (BRBFs) have been used as lateral force-resisting systems for low-, to mid-rise buildings. Residual Interstory Drift (RID) of BRBFs plays a key role in deciding to retrofit buildings after seismic excitation; however, existing formulas have limitations and cannot effectively help civil engineers, e.g., FEMA P-58, which is a conservative estimation method. Therefore, there is a need to...
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Increasing the Seismic Resistance of Wood-frame Buildings by Applying PU Foam as Thermal Insulation
PublikacjaWood-frame buildings are very common in regions that are exposed to earthquakes. Most of residential buildings are constructed using this technology; therefore, the seismic resistance of them is really essential in order to prevent human losses and structural damage. The aim of the present article is to show the results of the detailed numerical FEM analysis focused on the seismic behaviour of the wood-frame house with different...
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Application of discrete wavelet transform in seismic nonlinear analysis of soil–structure interaction problems
PublikacjaSimulation of soil-structure interaction (SSI) effects is a time-consuming and costly process. However, ignoring the influence of SSI on structural response may lead to inaccurate results, especially in the case of seismic nonlinear analysis. In this paper, wavelet transform methodology has been utilized for investigation of the seismic response of soil-structure systems. For this purpose, different storey outrigger braced buildings...
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Active Learning on Ensemble Machine-Learning Model to Retrofit Buildings Under Seismic Mainshock-Aftershock Sequence
PublikacjaThis research presents an efficient computational method for retrofitting of buildings by employing an active learning-based ensemble machine learning (AL-Ensemble ML) approach developed in OpenSees, Python and MATLAB. The results of the study shows that the AL-Ensemble ML model provides the most accurate estimations of interstory drift (ID) and residual interstory drift (RID) for steel structures using a dataset of 2-, to 9-story...
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Parametric analysis of Istanbul's Ring Road viaduct for three levels of seismic load
PublikacjaThe paper presents a parametric analysis of the Istanbul's ring road viaduct that is currently under construction within the Northern Marmara Highway project. The structure, due to its location on seismic prone areas is exposed to seismic loads of different strengths and different return periods. The study is focused on concrete bridge supports that are design to work in nonlinear range. The parametric study, conducted in MATLAB...
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Shaking table experimental study on damage mechanism of the disconnecting switch under seismic excitation
PublikacjaThe efficiency of the energetic network is a very import safety issue in the region experienced by the earthquake. High voltage disconnecting switches are important elements of the energetic infrastructure used to separate electric circuits (i.e. during repairs), which should not be damaged remaining fully operational. The aim of the paper is to show the results of the shaking table experimental investigation focused on damage...
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Effects of Column Base Flexibility on Seismic Response of Steel Moment-Frame Buildings
PublikacjaSteel Moment Resisting Frames (SMRFs) are very popular lateral load resisting systems in many seismically active regions. However, their seismic response is strongly dependent on the rotational fixity of column base connections. Despite many studies (both experimental and numerical) in this particular area, available approaches for estimating column base flexibility have been validated only against laboratory test data. In the...
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Building damage due to structural pounding during earthquakes
PublikacjaEarthquake-induced pounding between adjacent buildings has been identified as one of the reasons for substantial damage or even total collapse of colliding structures. A major reason leading to interactions in buildings results from the differences in their dynamic parameters and also from insufficient distance between the structures. Although the research on structural pounding has been much advanced, the studies have mainly been...
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Experimental study on the behaviour of steel columns under seismic-induced axial impact load
PublikacjaIt has been observed during major earthquakes that the so called soft-storey failure of an upper floor of a structure results in large impact load acting on structural members of the lower storeys. It may further lead to progressive collapse of the whole structure substantially intensifying human and material losses. Therefore, the aim of this paper is to investigate experimentally the behaviour of columns under bending (observed...
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Friction Tuned Mass Dampers in Seismic-Excited High-Rise Buildings with SSI Effects: A Reliability Assessment
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Effective Formula for Impact Damping Ratio for Simulation of Earthquake-induced Structural Pounding
PublikacjaStructural pounding during earthquakes may cause substantial damage to colliding structures. The phenomenon is numerically studied using different models of collisions. The aim of the present paper is to propose an effective formula for the impact damping ratio, as a parameter of the impact force model used to study different problems of structural pounding under seismic excitations. Its accuracy has been verified by four various...
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Parametric analysis of Istanbul's Ring Road viaduct for three levels of seismic load
PublikacjaThe paper presents a numerical analysis of the Istanbul's ring road viaduct that is currently under construction within the Northern Marmara Highway project. The structure, due to its location on seismic prone areas is exposed to seismic loads of different magnitude and different return periods. The study is fo-cused on concrete bridge supports that are design to work in nonlinear range. The study, conducted in SOFISTIK environment,...
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Finite-element analysis of a base-isolated multi-storey steel building under seismic motions
PublikacjaNumerical simulation of the seismic behaviour of a multi-storey steel building, both fixed-base and base-isolated, under the 1940 El Centro earthquake was performed in this paper. The analyzed 4-storey building was decoupled from the shaking ground with the Polymeric Bearings, which can be considered a proposal of a new seismic isolation system. It consists of rectangular-shaped blocks made of a specially prepared flexible polymeric...
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Enhancing seismic performance of rigid and semi-rigid connections equipped with SMA bolts incorporating nonlinear soil-structure interaction
PublikacjaNowadays, using smart connections can improve the performance of buildings with some recentering features that are from the superelastic behavior of Shape Memory Alloys (SMAs). It seems that there is different rigidity between the designed connection and the real one in Steel Moment-Resisting Frames (SMRFs), which can be considered as a problematic issue due to the importance of connections in seismic performance assessment. This...
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Mathematical Modelling of a Seismic Isolation System to Protect Structures During Damaging Earthquakes
PublikacjaThe present study aims to determine the effectiveness of a nonlinear mathematical model in simulating complex mechanical behaviour of a seismic isolation system to protect structures during strong and damaging earthquakes. In order to construct the Polymeric Bearings considered in this research, a specially prepared flexible polyurethane elastomer with increased damping properties has been used. The usefulness of the proposed mathematical...
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Numerical Study on Seismic Response of a High-Rise RC Irregular Residential Building Considering Soil-Structure Interaction
PublikacjaThe objective of the present study is to investigate the importance of soilstructure interaction effects on the seismic response of a high-rise irregular reinforced-concrete residential building. In order to conduct this research, a detailed three-dimensional structure model was subjected to various earthquake excitations, also including a strong mining tremor. Soil-foundation flexibility was represented using the spring-based...
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Predicting the peak structural displacement preventing pounding of buildings during earthquakes
PublikacjaThe aim of the present paper is to verify the effectiveness of the artificial neural network (ANN) in predicting the peak lateral displacement of multi-story building during earthquakes, based on the peak ground acceleration (PGA) and building parameters. For the purpose of the study, the lumped-mass multi-degree-of-freedom structural model and different earthquake records have been considered. Firstly, values of stories mass and...
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Optimization-based stacked machine-learning method for seismic probability and risk assessment of reinforced concrete shear walls
PublikacjaEfficient seismic risk assessment aids decision-makers in formulating citywide risk mitigation plans, providing insights into building performance and retrofitting costs. The complexity of modeling, analysis, and post-processing of the results makes it hard to fast-track the seismic probabilities, and there is a need to optimize the computational time. This research addresses seismic probability and risk assessment of reinforced...
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Verification of Formulas for Periods of Adjacent Buildings Used to Assess Minimum Separation Gap Preventing Structural Pounding during Earthquakes
PublikacjaInsufficient separation distance between adjacent buildings may lead to serious damages during earthquakes due to structural pounding. The best way to prevent collisions is to provide sufficiently large separation distance between the structures. In this paper, the periods of two closely-spaced linear and nonlinear buildings have been investigated so as to accurately assess the minimum in-between separation gap. A new equation...
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Pounding between high-rise buildings with different structural arrangements
PublikacjaEarthquake-induced structural pounding has led to significant damages during previous earthquakes. This paper investigates the effect of pounding on the dynamic response of colliding high-rise buildings with different structural arrangements. Three 3-D buildings are considered in the study, including 5-storey building, 7-storey building and 9-storey building. Three pounding scenarios are also taken into account, i.e. pounding between...
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Earthquake-induced pounding between superstructure segments of isolated bridge
PublikacjaThe use of seismic isolation in bridges is considered as one of the most promising advanced technologies to enhance the structural safety during earthquakes. However, the method results in larger displacements of superstructure segments increasing the probability of pounding between them. Reports after severe ground motions show that the earthquake-induced structural pounding may lead to significant damage in isolated bridges....
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Damaged plasticity model - seismic analysis of structure of the Petronas Twin Towers (Kuala Lumpur) in Malaysia
PublikacjaThe article presents numerical simulations for the modelling of seismic impact on the structure of Petronas Twin Towers (Kuala Lumpur) in Malaysia with application of two methods. The Response Spectrum method, in which a spectrum of the structure's responses to an earthquake's impact is generated and the Acceletogram (BETA) method, in which we generate dynamic load in the form of a diagram of the connection between acceleration...
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Experimental study on the effectiveness of polymer dampers in reduction of structural vibrations
PublikacjaVibrations of civil engineering structures, generated by dynamic loads, may be very dangerous to the structures themselves as well as may have significant influence on human perception and comfort. A number of different methods have been proposed in order to minimize such situations. This concern newly designed structures as well as those which dynamic properties have to be modified due to problems with excessive vibrations. One...
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Experimental study on effectiveness of polymer dampers in reduction of structural vibrations
PublikacjaVibrations of civil engineering structures, generated by dynamic loads, may be very dangerous to the structures themselves as well as may have significant influence on human perception and comfort. A number of different methods have been proposed in order to minimize such situations. This concern newly designed structures as well as those which dynamic properties have to be modified due to problems with excessive vibrations. One...
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Incremental Dynamic Analysis and Fragility Assessment of Buildings with Different Structural Arrangements Experiencing Earthquake-Induced Structural Pounding
PublikacjaStructural pounding is considered as one of the most critical phenomena occurring during earthquakes. This paper presents the incremental dynamic analysis and fragility assessment of buildings experiencing earthquake-induced pounding. Three 3-D buildings with different number of storeys and under different structural arrangements have been considered. Three pounding scenarios have been taken into account, i.e. pounding between...
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Linking of adjacent three-storey buildings for mitigation of structural pounding during earthquakes
PublikacjaThe reports after major earthquakes indicate that the earthquake-induced pounding between insufficiently separated buildings may lead to significant damage or even total collapse of structures. An intensive study has recently been carried out on mitigation of pounding hazards so as to minimize the structural damages or prevent collisions at all. The aim of this paper is to investigate the effectiveness of the method when two adjacent...
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Seismic Response Analysis of Knee-Braced Steel Frames Using Ni-Ti Shape Memory Alloys (SMAs)
PublikacjaShape Memory Alloys (SMAs) are known as active materials that can be widely used for structural purposes due to their flag-shape behavior under loading and reloading. Their unique characteristics provided a potential solution for civil engi-neers especially to model buildings with the capability of dissipating seismic en-ergy. In this study, the main purpose is to explore the seismic behavior of Knee-Braced Frames (KBFs) and...
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Effectiveness of a mathematical model in simulating nonlinear mechanical behaviour of a seismic isolation system made of polymeric bearings
PublikacjaThe present study was focused on determining the effectives of a nonlinear mathematical model in simulating complex mechanical behaviour of a seismic isolation system made of Polymeric Bearings. The proposed mathematical model defines the lateral force as a nonlinear function of the shear displacement and the deformation velocity. The effectiveness of the proposed mathematical model was verified by comparing the seismic response...
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Enhancing seismic performance of buckling-restrained brace frames equipped with innovative bracing systems
PublikacjaNowadays, to improve the performance of conventional bracing systems, in which, buckling in the pressure loads is the main disadvantage, the buckling-restrained brace (BRB) is introduced as a solution. In this study, the performance of the BRB system was improved with innovative lateral-resisting systems of double-stage yield buckling-restrained brace (DYB), and a combination of DYB improved with shape memory alloy (SMA) materials...