Article
Engineering, Industrial
Rui Pang, Dezhi Zai, Bin Xu, Jun Liu, Chunfeng Zhao, Qunying Fan, Yuting Chen
Summary: This study proposes a new framework to analyze the effects of stochastic seismic sequences on the dynamic response and reliability of AP1000 nuclear power plants (NPPs). Stochastic mainshock-aftershock sequences are generated, and the effects of aftershocks on NPPs are highlighted using acceleration and displacement as response indices and damage indicators. The probabilistic information and reliability of NPPs are obtained based on the direct probability integration method and the absorbing condition method. The results show that seismic sequences have a larger dynamic response and cause more damage to the NPPs compared to a single mainshock. Aftershocks reduce the reliability of NPPs, and the degree of reduction is related to the thresholds.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Article
Engineering, Geological
Chunfeng Zhao, Lei Zhou, Shenjiang Huang, Avinash Gautam
Summary: This study investigates the impact of aftershock duration on the seismic fragility of shield buildings using a three-dimensional finite element model, showing that longer duration aftershocks may worsen cumulative damage to already damaged structures, while initial damage levels significantly affect fragility curves.
BULLETIN OF EARTHQUAKE ENGINEERING
(2022)
Article
Construction & Building Technology
Xu Bao, Changhai Zhai, Longjun Xu
Summary: This paper proposes a new framework for assessing the time-dependent risk of a containment building subjected to mainshock-aftershock sequences. A Markov-based approach is used to analyze the system, considering the fragility of nonstructural components and the contributions of failure events and accident sequences. State-dependent fragility curves are generated to account for the seismic performance of damaged structures. The results show the importance of considering aftershocks in seismic risk management for containment buildings.
JOURNAL OF STRUCTURAL ENGINEERING
(2022)
Article
Engineering, Geological
Guoxing Chen, Shengdong Zhu, Weiyun Chen, Xiaojun Li, Charng Hsein Juang
Summary: With the increase of nuclear power plants, it is necessary to consider the nonlinear behavior of soil and the soil-pile-structure interaction (SPSI) in the seismic response analysis of pile-supported nuclear-island buildings constructed on coastal deposits. This study proposes a 3D integrated simulation method to evaluate the seismic responses of such buildings and finds that scenario earthquakes with abundant long period components may have more destructive potential.
BULLETIN OF EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Civil
Liangkun Wang, Ying Zhou, Weixing Shi
Summary: This study investigates the control effect of a semi-active tuned mass damper (STMD) on nonlinear buildings under mainshock-aftershock sequences. The STMD is able to adapt to the nonlinear behavior of the structure in different time segments by adjusting its stiffness based on a wavelet transform algorithm, and enhance energy dissipation by switching its damping coefficient in real time. Results show that the STMD effectively controls the displacement responses and base shear of the structure, and performs better than the passive TMD in reducing plastic deformation and dissipating energy.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Engineering, Civil
Hamidreza Anajafi, Ricardo A. Medina, Christoph Adam
Summary: Recorded floor acceleration data from instrumented buildings are used to evaluate the impact of different parameters on the seismic response of nonstructural components. Relationships proposed by the authors for estimating NSC damping modification factor are validated using this data.
JOURNAL OF EARTHQUAKE ENGINEERING
(2022)
Article
Nuclear Science & Technology
Yousang Lee, Ju-Hyung Kim, Hong-Gun Park
Summary: This study analyzed the floor response spectrum of equipment in nuclear power plants using a 3-D finite element model. It was found that the presence of large openings in the floor significantly affected the floor response. Additionally, a seismic fragility analysis showed that the location-dependent disparity in the floor response spectrum had an impact on the high confidence low probability of failure.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2023)
Article
Construction & Building Technology
Ali Khansefid
Summary: This research investigates the impact of neglecting nonlinear structural behavior on estimated seismic risk assessment. By modeling earthquake hazard scenarios and conducting Monte Carlo simulations, the study examines the effects of different structural responses on building performance and losses.
ADVANCES IN STRUCTURAL ENGINEERING
(2021)
Article
Engineering, Civil
Seong-Hoon Hwang, Mehran Shokrabadi, Sujith Mangalathu, Jong-Su Jeon
Summary: The structural analysis of steel moment-resisting frame buildings often overlooks the participation of interior gravity frames and composite floor slab action in their lateral strength and stiffness, as well as the effects of aftershocks. This study investigates the impact of structural modeling assumptions and the inclusion of aftershocks on the seismic vulnerability and time-dependent lifetime seismic risk of a group of steel moment-resisting frame buildings.
Article
Construction & Building Technology
Ruizhao Zhu, Tong Guo, Solomon Tesfamariam, Yanqing Xu
Summary: The self-centering viscous-hysteretic devices (SC-VHDs) show significant effectiveness in reducing peak and residual drifts in seismic performance testing. Results indicate that under mainshock-aftershock sequences, SC-VHD frames experience larger drifts compared to mainshock-only sequences. Numerical analysis validates the seismic performance of SC-VHD frames at different floors.
JOURNAL OF STRUCTURAL ENGINEERING
(2022)
Article
Nuclear Science & Technology
Zhi Zhang, Chenning Song, Zhining Duan, Zhi Cheng
Summary: This study investigates the influence of the gravity cooling water tank on the seismic response of nuclear power plant structures. Through shaking table tests and numerical analysis, it is found that the presence of water and water sloshing can reduce the natural frequency and seismic response of the structures.
SCIENCE AND TECHNOLOGY OF NUCLEAR INSTALLATIONS
(2022)
Article
Agriculture, Multidisciplinary
Xiaoshuai Wang, Jiegang Wu, Qianying Yi, Guoqiang Zhang, Thomas Amon, David Janke, Xiusong Li, Bin Chen, Yong He, Kaiying Wang
Summary: A study using Computational Fluid Dynamics technique explored the ventilation performance of multi-floor animal buildings, revealing limited differences in airflow patterns among floors and varying ventilation rates with floor number. It is recommended to focus on the ventilation rate of the first floor during design, and increasing yard width can mitigate negative effects of floor number on ventilation rates.
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2021)
Article
Engineering, Civil
Shi-Li Guo, Yang Xiang, Guo-Qiang Li
Summary: This paper focuses on the floor seismic response spectrum (FSRS) of buildings equipped with visco-elastic (VE) decoupled floors. A FSRS model is proposed based on the complex modal decomposition process and the stochastic dynamics of linear oscillators. Parameter analysis shows that FSRS can be mitigated by using a more flexible VE decoupler and a larger mass ratio, and VE decoupled floors installed at the roof level are more effective than those at lower levels.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Engineering, Civil
Jae-Wook Jung, Min Kyu Kim, Jung Han Kim
Summary: Seismic isolation is an innovative means to improve the seismic safety of nuclear power plants against strong earthquakes. However, applying seismic isolation systems to real NPP structures faces difficulties due to the variability of material properties and the nonlinear behavior of the isolation system.
ENGINEERING STRUCTURES
(2022)
Article
Energy & Fuels
Prakhar Dixit, Vennapusa Jagadeeswara Reddy, Aravind Dasari, Sujay Chattopadhyay
Summary: Zinc nitrate hexahydrate/expanded perlite composite was prepared, and then applied to electric radiant floor heating with a paraffin coating. Experimental and simulation studies showed that the composite phase change material has good thermal buffering performance.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Nuclear Science & Technology
Chunfeng Zhao, Na Yu, Tao Peng, Vincenzo Lippolis, Aldo Corona, Y. L. Mo
PROGRESS IN NUCLEAR ENERGY
(2020)
Article
Construction & Building Technology
S. Y. Xiao, J. B. Li, Y. L. Mo
ADVANCES IN STRUCTURAL ENGINEERING
(2020)
Article
Engineering, Civil
Chunfeng Zhao, Na Yu, Y. L. Mo
Article
Engineering, Civil
Xin Ye, Chunfeng Zhao, Kaicheng He, Lei Zhou, Xiaojie Li, Jingfeng Wang
Summary: Various numerical studies have been conducted to investigate the blast behavior of precast concrete sandwich panels (PCSP) as components of precast concrete structures (PCS). The study established a three-dimensional finite element model and conducted explosion tests to validate the accuracy and reliability of the model. Parametric analyses were carried out to investigate factors influencing PCSP blast resistance, with results showing weaker blast resistance compared to conventional reinforced concrete slabs.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Chunfeng Zhao, Chao Zeng, Hsuanwen Huang, Junwu Dai, Wen Bai, Jingfeng Wang, Y. L. Mo
Summary: Periodic materials can block specific frequency waves, reducing unwanted seismic waves in civil engineering. Adjusting frequency band gaps can help isolate environmental vibrations or seismic waves in civil engineering.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Satya Sapath Roy, Jamshaid Sawab, Tiamin Zhou, Jiaji Wang, Y. L. Mo, Thomas T. C. Hsu
Summary: This study investigates the shear behavior of six full-scale Inverted-T Bent Caps (ITBC) specimens with different skew angles, comparing traditional and uniform skewed reinforcement design. The research explores the impact of skew angle and rebar arrangement on structural performance, providing insights into the design and construction of skewed reinforcing in ITBCs.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Mechanical
Hsuan Wen Huang, Jiaji Wang, Chunfeng Zhao, Y. L. Mo
Summary: A novel seismic isolation technique called Periodic Barriers, incorporating trench-type wave barriers and metamaterial, is introduced in this research. Two-dimensional finite-element simulation is used to study the performance of the barriers adapting the metamaterial, with validation conducted through experiments on metamaterial-based foundation. Various analysis methods are adopted to improve computing efficiency and the simulation results show that the periodic barriers perform as expected.
JOURNAL OF ENGINEERING MECHANICS
(2021)
Article
Green & Sustainable Science & Technology
Na Yu, Chunfeng Zhao
Summary: This study examines the strategic choices of government, upstream enterprises, and downstream enterprises in collaborative innovation, finding that they have varying degrees of influence on each other's willingness to participate. Additionally, it concludes that government policy support and financial assistance have different impacts on upstream and downstream enterprises.
Article
Engineering, Civil
Chao Zeng, Chunfeng Zhao, Farhad Zeighami
Summary: This study investigates the dispersion relations of Rayleigh waves propagating through vertical oscillators on stratified media. The results show that only the foundational mode is strongly coupled with the vertical resonators at resonance, while higher-order surface modes cross the surface wave band gap reported in homogeneous media.
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
(2022)
Article
Engineering, Civil
Chunfeng Zhao, Kaicheng He, Lunhai Zhi, Xin Lu, Rong Pan, Avinash Gautam, Jingfeng Wang, Xiaojie Li
Summary: The steel-concrete composite structure is gradually being used in seismic and explosion-resistant designs due to its energy dissipation and impact resistance capabilities. Experimental and numerical studies have investigated the blast capacities of different composite slabs and have shown that the steel plate plays a dominant role in resisting blast loads and preventing damage due to its high tensile strength. The proposed empirical formula for mid-span deflection of composite slabs can accurately predict their behavior under blast conditions.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Chunfeng Zhao, Chao Zeng, Witarto Witarto, Hsuan Wen Huang, Junwu Dai, Y. L. Mo
Summary: This study validates the effectiveness of one-dimensional periodic foundation in reducing seismic response through experiments and numerical simulations, demonstrating its ability to act when seismic wave frequencies fall within the band gap range.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Chunfeng Zhao, Na Yu, Tao Peng
Summary: This study used IDA and MSA analysis methods to investigate the effectiveness of isolation devices in reducing the damage risk of isolated nuclear power plant structures, proposing fragility functions and performance levels for analysis. The results show that isolated structures have higher safety compared to non-isolated structures. The results also suggest that MSA fragility curves are more conservative than those obtained from IDA, with a maximum error of about 10% in the exceeding probabilities. These findings can provide practical guidance for the design of isolated nuclear power plant structures.
Article
Engineering, Geological
Chunfeng Zhao, Lei Zhou, Shenjiang Huang, Avinash Gautam
Summary: This study investigates the impact of aftershock duration on the seismic fragility of shield buildings using a three-dimensional finite element model, showing that longer duration aftershocks may worsen cumulative damage to already damaged structures, while initial damage levels significantly affect fragility curves.
BULLETIN OF EARTHQUAKE ENGINEERING
(2022)
Article
Construction & Building Technology
Xiaoming Qin, Satya Sapath Roy, Haibei Xiong, Yi-Lung Mo, Qingzhao Kong
Summary: This paper presents a study on multidirectional crack monitoring of concrete structures using an embedded 3D piezoceramic sensing array. The authors propose a numerical-guided sensor placement strategy and validate its reliability through experimental and simulation results.
STRUCTURAL CONTROL & HEALTH MONITORING
(2022)
Article
Engineering, Civil
Lun-hai Zhi, Feng Hu, Chunfeng Zhao, Jingfeng Wang
Summary: This paper proposes an improved variational mode decomposition (IVMD) algorithm for structural modal parameter estimation based on non-stationary responses. The feasibility and accuracy of the proposed procedure are evaluated by both numerical and full-scale examples, successfully identifying the natural frequencies and damping ratios from vibration responses with high noise and non-stationary characteristics. The results illustrate that the proposed procedure provides a powerful approach to identify the modal parameters of civil structures using non-stationary responses.
STRUCTURAL ENGINEERING AND MECHANICS
(2021)
