Article
Engineering, Civil
Yichen Zhang, Raffaele De Risi, Nicholas A. Alexander
Summary: This paper proposes an innovative physical implementation of a previously reported frictional sliding on a sprung slope (FSSS) device. The device uses the end stiffness of cantilevers as the sprung-slope, generating amplitude varying normal and frictional forces along the sliding plane. Two scaled prototypes were designed and tested, and the results demonstrated consistency with theoretical analysis.
ENGINEERING STRUCTURES
(2022)
Article
Engineering, Civil
Shangtao Hu, Menggang Yang, Dongliang Meng, Renkang Hu
Summary: This study aims to evaluate the damping performance of leaked fluid viscous dampers (FVDs). Through a series of cyclic tests on a large-tonnage leaked FVD, the performance degradation mechanism was revealed and analytical models for simulating the hysteresis characteristics of the leaked FVD were established and verified. The case study showed that oil leakage causes a gap phenomenon in the hysteresis curves but does not alter the mechanical parameters of the FVD after the gap has been consumed. The leaked FVD is more prone to force-exceeding and stroke-exceeding failures, thus requiring prompt replacement.
Article
Construction & Building Technology
Xiaoying Sun, Hangzi Wu, Yue Wu, Ning Su
Summary: The wind-induced responses of a 1040-meter-high skyscraper were calculated based on wind tunnel test data, revealing the need to strengthen torsional stiffness. Mass and viscous dampers were used to control wind-induced responses, with the hybrid control method proving optimal.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Civil
Cun Hui, Zhongyi Zhou, Yonggang Li, Yongkang Jiao, Ran Hai
Summary: A low-cost double-sided slotted steel tube shear damper is proposed to absorb seismic energy through the elastic-plastic deformation in the plane of the slotted steel plate on the side of the steel tube. The damper exhibits strong plastic deformation capacity, good seismic performance, and energy dissipation capacity. Quasi-static tests and finite element simulations validate the performance and effectiveness of the damper.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2022)
Article
Engineering, Civil
Xiantie Wang, Chuandong Xie, Zihan Jia, George Vasdravellis
Summary: An innovative PT connection using slender steel rectangles as energy-dissipating elements was proposed in this study, which showed that the energy-dissipating capacity can be increased by increasing the number of steel rectangles while the re-centering capacity remains unaffected. Experimental results indicated that specimens with a smaller width of steel rectangles exhibited typical three-plastic-hinge buckling, while smaller thickness of the steel segments led to a multi-wave out-of-plane buckling mode.
ENGINEERING STRUCTURES
(2022)
Article
Construction & Building Technology
Canxing Qiu, Tianyi Huang, Jiawang Liu
Summary: This paper proposes an assembled X-shaped flexural steel damper and analyzes its performance through experiments and numerical simulations. The results show that the damper has excellent hysteretic performance and energy dissipation capacity, effectively reducing structural displacements during earthquakes. The parametric analysis results agree with the predictions, indicating that the numerical model can accurately reflect the mechanical behavior of the damper.
ADVANCES IN STRUCTURAL ENGINEERING
(2023)
Article
Acoustics
Steen Krenk
Summary: The tuning and efficiency of a local viscous damper on a flexible structure is described using a cubic polynomial approximation of the characteristic equation. Increasing the viscosity to the limit of locking of the device can either increase or decrease the modal resonance frequency. A cubic approximation is developed to cover both cases, representing the effect of non-resonant modes with either an equivalent stiffness or inertia term. The cubic root-locus curve is determined by the change in resonance frequency and a non-dimensional damping parameter.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Cheng Su, Jianhua Xian
Summary: This study focuses on using topology optimization to design structures with non-linear fluid viscous dampers and optimizing them under non-stationary random seismic excitations. By utilizing the EL-ETDM method and the gradient-based method of moving asymptotes, the optimization of non-linear viscous dampers is achieved.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Construction & Building Technology
Wenxue Zhang, Lijun Su, Cheng Zhang, Yongrui Zheng, Weifeng Yang
Summary: This study proposed a new type of winding rope shock absorption device activated by a fluid viscous damper (WRD-D), which can effectively reduce the seismic requirements of fixed piers and superstructure displacements.
ADVANCES IN STRUCTURAL ENGINEERING
(2022)
Article
Engineering, Civil
Fangyu Li, Yongfeng Du, Na Hong, Hu Li, Peihong Chi
Summary: A novel replaceable graded-yielding energy-dissipating connector (RGEC) is proposed for prefabricated concrete beam-column joints to improve seismic performance and earthquake resilience. The RGECs, assembled on the upper and lower sides of the beam end, allow for plastic deformation concentration on bending-shear components and buckling segment, enabling rapid restoration of structural seismic performance through connector replacement. Tests and mechanical models demonstrate excellent seismic performance in terms of strength capacity, deformation capacity, energy dissipation capacity, and stiffness degradation. Finite element models analyze the deformation behavior considering key design factors.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Civil
Chunyu Li, Jing Wu, Jinyang Zhang, Chao Tong
Summary: A precast concrete frame with replaceable energy-dissipating connectors (REDC-PCF) is proposed, which showed good seismic performance and stable hysteretic behaviors through experiments and numerical simulations. The REDCs act as energy dissipating devices during medium or large earthquakes, protecting the precast concrete elements from severe damage. The numerical analysis model constructed using Opensees showed good agreement with the test results.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Jinping Li, Bin Wu, Zhen Wang, Haowen Yang, Guoshan Xu
Summary: The resilience of civil engineering structures and the measurement of residual deformation have become a focus of attention. A self-centering viscous damper (SCVD) is proposed to enhance the seismic capacity of structures and dissipate energy. The working principle, numerical modeling, specimen design, cyclic tests, and real-time hybrid tests of the SCVD are described in detail, validating its excellent effect on the seismic residual deformation of structures.
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
(2022)
Article
Construction & Building Technology
Yu Diao, Jitao Bai, Jianyou Huang, Pengjin Li, Chao Yang
Summary: This study examined the effect of L-Asp on the shear strength, friction angle, and cohesion of mortar through direct shear tests. It was found that higher normal stress can promote shear shrinkage and inhibit shear dilation. Pre-peak cyclic shear tests were conducted under different normal stresses to study the cyclic response of BCP-treated mortar. Shear softening was observed and the stress-strain behavior of the specimen was further investigated. The results showed that high normal stress can alleviate the decrease in shear strength after cyclic loading and more loading cycles led to lower post-cyclic shear strength and cohesion.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Engineering, Chemical
Jia-Xiu Wu, Ying-Chih Liao
Summary: A thermal comfort control model based on heat flux regulation was developed in this study to ensure thermal comfort in the human-clothing-environment system. By optimizing the control strategy for an electric heater using a mathematical model, skin temperature and sensible heat loss can be stably controlled within the standard thermal comfort range.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Engineering, Civil
Wenxue Zhang, Cheng Zhang, Lijun Su, Yongrui Zheng, Xiuli Du
Summary: This study proposes a winding rope fluid viscous damper (WRFVD) that uses winding ropes to amplify the damping force of a fluid viscous damper. Experimental results show that the WRFVD is a velocity-dependent damping device with significant and stable energy dissipation capacity. The winding rope amplification mechanism effectively amplifies the damping force and energy dissipation of the fluid viscous damper.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Civil
Samira Ebrahimi, Seyed Rasoul Mirghaderi, Seyed Mehdi Zahrai
Summary: This paper proposes a new connection called Through-Gusset Plate (TGP), which uses concrete infill and gusset plate to alleviate the distortion and out-of-plane deformation in HSS column face. The experimental results show that this novel connection significantly increases the lateral stiffness, strength, and energy dissipation capacity of frame specimens, as well as the normal force component capacity of the connection.
JOURNAL OF EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Civil
Mohammadreza Khoshkalam, Mohamad Hosein Mortezagholi, Seyed Mehdi Zahrai
Summary: Various yielding dampers have been proposed to improve seismic performance of structures, with ADAS dampers considered as energy dissipation tools but facing limitations in large deformations due to unexpected axial force. A modified ADAS damper has been proposed in this study, with improved performance by changing boundary conditions and geometry to transfer axial force through side plates to bracings. Evaluations show that MADAS dampers have better energy dissipation in large deformations compared to ADAS dampers.
JOURNAL OF EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Civil
Akbar Bathaei, Seyed Mehdi Zahrai
Summary: In this study, the vibrations of a structure under seismic load are controlled using a semi-active control approach with the help of MR damper and fuzzy logic algorithm decision system. The performance of the control system is improved by using a floating fuzzy inference system with variable range for membership functions.
Article
Engineering, Multidisciplinary
Erfan Najaf, Hassan Abbasi, Seyed Mehdi Zahrai
Summary: This study investigates the simultaneous use of waste glass powder, microsilica, and polypropylene fibers to make sustainable lightweight concrete with high compressive and flexural strengths, ductility, and impact resistance. Results show that the best percentages of microsilica and glass powder are 10% and 25% respectively, while the use of 1.5% fibers significantly improves the strength and impact resistance of the lightweight concrete. Furthermore, reducing the amount of cement used by 10% can result in a significant reduction of CO2 emissions.
INTERNATIONAL JOURNAL OF STRUCTURAL INTEGRITY
(2022)
Article
Engineering, Civil
Masoud Ami, Seyed Mehdi Zahrai
Summary: The article examines the resistance of rubberized concrete-filled double steel tubular columns and proposes strategies to enhance their strength. The findings suggest that using 20% rubber particles can significantly increase the energy absorption capacity and ductility of the columns, while increasing the number of headed studs and reducing their intervals can enhance the ultimate strength of the columns.
Article
Engineering, Civil
Morteza Mohemmi, Seyed Mehdi Zahrai
Summary: This research investigates the efficiency of using box and pipe HSS segments as seismic fuses in chevron braced frames. It concludes that vertical box fuses (VBFs) with higher aspect ratio and larger cross-section demonstrate reasonable behavior in energy dissipation and provide more stable hysteresis loops. However, vertical pipe fuses (VPFs) with high aspect ratios encounter stiffness reduction in large displacement cycles and require the use of vertical stiffeners to improve their performance. Stiffened vertical pipe fuses (SVPFs) show proper performance by using stiffeners on VPFs.
INNOVATIVE INFRASTRUCTURE SOLUTIONS
(2022)
Article
Construction & Building Technology
Samira Ebrahimi, Seyed Rasoul Mirghaderi, Seyed Mehdi Zahrai
STRUCTURAL DESIGN OF TALL AND SPECIAL BUILDINGS
(2023)
Article
Computer Science, Artificial Intelligence
Ommegolsoum Jafarzadeh, Seyyed Arash Mousavi Ghasemi, Seyed Mehdi Zahrai, Ardashir Mohammadzadeh, Ramin Vafaei Poursorkhabi
Summary: This paper introduces a novel adaptive neurochaotic fuzzy control system based on type-2 fuzzy systems to reduce seismic responses in multistory structures with active tuned mass dampers. The proposed control system utilizes online estimation and adaptive parameter training methods to achieve efficient reduction of seismic responses such as maximum displacement and acceleration.
INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS
(2023)
Article
Engineering, Civil
Ata Abdollahpour, Seyed Mehdi Zahrai
Summary: This study investigates the behavior of a two-level system consisting of a yielding pipe damper and rotational friction damper within a steel frame. The proposed system includes two types of fuses for energy dissipation in two stages. The system utilizes a rotational friction damper instead of hinged connections in the toggle brace system, connected to a pipe damper with a limited gap. The results show that the hybrid two-level system has comparable flexibility to the conventional toggle brace damper and can sustain longer lateral displacements.
STRUCTURAL ENGINEERING AND MECHANICS
(2023)
Article
Construction & Building Technology
Mohammad Sadra Rajabi, Hosein Taghaddos, Seyed Mehdi Zahrai
Summary: Due to the occurrence of severe and large magnitude earthquakes each year, earthquake-prone countries suffer significant financial damages and loss of life. Teaching essential safety measures will lead to a generation that can perform basic procedures during an earthquake, which is an essential and effective solution in preventing the loss of life in this natural disaster. Virtual Reality (VR) technology has been used as a tool to educate people on safety matters. The study evaluates the effect of education and premonition on the incorrect decision-making of residents under the stressful conditions of an earthquake.
Article
Engineering, Civil
Soroush Nodehi, Seyed Mehdi Zahrai
Summary: Despite its disadvantages, the use of a soft story can reduce damage to upper floors by concentrating drift in a specific story. The Gapped-Inclined Brace (GIB) with reduced P-delta effects and controlled soft story stiffness allows buildings to take advantage of the soft story and increase their capacity for energy dissipation. In this study, OpenSees software is used to validate and modify the GIB model, and the analysis method for the element is changed for design purposes. The retrofitted structure using the modified element shows improved performance according to nonlinear static analysis, nonlinear dynamic analysis, and incremental dynamic analysis.
STRUCTURAL ENGINEERING AND MECHANICS
(2022)
Article
Engineering, Civil
Akbar Bathaei, Seyed Mehdi Zahrai
Summary: This research investigates the impact of time delay on control systems in engineering structures, proposing the use of predictive control to compensate for the delay, alongside a semi-active vibration control approach using MR dampers. Results indicate a significant improvement in control system performance after implementing structure behavior prediction to overcome time delays.
STRUCTURAL ENGINEERING AND MECHANICS
(2022)
Article
Engineering, Mechanical
Erfan Najaf, Maedeh Orouji, Seyed Mehdi Zahrai
Summary: In this research, efforts were made to produce environmentally friendly lightweight (LW) concrete with high strength by using waste glass powder, nanosilica, and recycled fibers. The experimental results showed that the optimal sample had a compressive and tensile strength roughly 1.7 and 1.6 times higher than the control specimen after 28 days, respectively. Additionally, using 3% nanosilica instead of cement reduced greenhouse gas emissions by about 3%.
NONLINEAR ENGINEERING - MODELING AND APPLICATION
(2022)
Article
Engineering, Civil
Ahmad Modheji, Seyed Mehdi Zahrai
Summary: This paper experimentally investigates the behavior of a Visco-Plastic Damper (VPD) and confirms its performance in energy dissipation. The results show that the VPD has a higher energy dissipation compared to ordinary viscoelastic dampers.
STRUCTURAL ENGINEERING AND MECHANICS
(2022)
