A Theoretical Study of Estimating the Elastic Responses of Framed Self-Centering Wall Structures under Lateral Loading

Xiaobin Hu,Chen Lu,Xiaoqing Zhu,Xiangdong Xie 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.12

The framed self-centering wall (FSCW) structure is a newly-emerged special type of seismic-resistant system. However, the related studies rarely concern the theoretical investigation of the FSCW structures subjected to lateral loading, which is of great importance for seismic design of the FSCW structures. In view of this, the analytical model of the FSCW structures is firstly developed, then the fundamental equations that govern the elastic responses of FSCW structures under lateral loads are formulated and the corresponding analytical solutions are derived. Meanwhile, the developed analytical model is validated by the finite element method, which shows that the developed model has a good reliability in predicting the elastic responses of FSCW structures sustaining lateral loading. Utilizing the proposed method, the effects of the post-tensioned (PT) tendon and dampers on the behaviors of the FSCW structure under lateral loading are investigated. Moreover, a comparative study of mechanical performance between the FSCW structure and conventional structures under lateral loading is conducted. The results show that, in terms of the lateral displacement and shear force responses of the frame, the mechanical performance of the FSCW structure subjected to lateral loading generally falls in between those of the conventional frame-shear wall structure and the moment-resisting frame structure.

Study of Fire Resistance Performance of Stiffened Welded Hollow Spherical Joint Under Axial Tension

Xiaobin Qiu,Tao Chen,Bingsheng Huang,Jingrui Zhu,Zhen Zhang,Haoyu Song 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.2

To study the fire resistance performance of stiffened welded hollow spherical joints under axial tension, two specimens with load ratios of 0.4 and 0.6 were subjected. The temperature distribution, failure mode, and fire resistance performance of stiffened welded hollow spherical joints under axial tension were obtained. The test results show that the failure mode of the joint was a pull-out failure. During the heating process, the closer to the spherical equator, the higher the spherical temperature, and the temperature of the sphere at the stiffener is lower than that of the sphere at the non-stiffener. The load ratio has a great influence on the refractory performance of the stiffened welded hollow sphere joint. When the load ratio of the specimen is reduced from 0.60 to 0.40, the fire resistance time of the specimen increases by 4.47 min, and the critical temperature increases by 21.3 °C. According to the European Code, the finite element model for the stiffened welded hollow spherical joints is established. The effect law of various influencing factors on the fire resistance performance of stiffened welded hollow spherical joints is studied. The research results show that reducing the load ratio and increasing the thickness of the sphere can significantly improve the fire resistance performance of the joint. The calculation formula of the critical temperature of steel members in the current standard not suitable for the calculation of the critical temperature of the welded hollow spherical joint. The critical temperature values with different load ratios recommended by the current standard were relatively more conservative. Taking the ambient temperature as the fire resistance temperature, the finite element analysis results were fitted, and the formula for calculating the fire resistance temperature of the stiffened welded hollow spherical joint was proposed.

Low-noise reconstruction method for coded-aperture gamma camera based on multi-layer perceptron

Rui Zhang,Xiaobin Tang,Pin Gong,Peng Wang,Cheng zhou,Xiaoxiang Zhu,Dajian Liang,Zeyu Wang 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.10

Accurate localization of radioactive materials is crucial in homeland security and radiological emergencies. Coded-aperture gamma camera is an interesting solution for such applications and can be developed into portable real-time imaging devices. However, traditional reconstruction methods cannot effectively deal with signal-independent noise, thereby hindering low-noise real-time imaging. In this study, a novel reconstruction method with excellent noise-suppression capability based on a multi-layer perceptron (MLP) is proposed. A coded-aperture gamma camera based on pixel detector and coded-aperture mask was constructed, and the process of radioactive source imaging was simulated. Results showed that the MLP method performs better in noise suppression than the traditional correlation analysis method. When the Co-57 source with an activity of 1 MBq was at 289 different positions within the field of view which correspond to 289 different pixels in the reconstructed image, the average contrast-to-noise ratio (CNR) obtained by the MLP method was 21.82, whereas that obtained by the correlation analysis method was 5.85. The variance in CNR of the MLP method is larger than that of correlation analysis, which means the MLP method has some instability in certain conditions.

Non-probabilistic Integrated Reliability Analysis of Structures with Fuzzy Interval Uncertainties using the Adaptive GPR-RS Method

Minghui Liu,Xiaoling Wang,Xiaobin Zhu,Wenlong Chen,Xiao Li 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.9

Due to its weak dependence on the quantity of variable samples, the non-probabilistic reliability analysis method based on the convex set model is applicable to practical problems in structural engineering with inherent uncertainties. However, when dealing with the black-box limit-state function issues in practical complex structural engineering, the traditional quadratic polynomial response surface (QP-RS) method has the problem of insufficient precision in approximating a highly nonlinear function. Meanwhile, fixing the limits of interval variables is trickier in case of scant samples and meager statistical information. To remedy the above deficiencies, this paper introduces a reasonable integrated reliability analysis approach. First, an adaptive Gaussian process regression response surface (GPR-RS) method that dynamically improves the fitted accuracy near the design point of the black-box limit-state function is formulated. Furthermore, the integrated reliability index with consideration of fuzzy interval uncertainties is presented. Three validation and two application examples are employed, which have justified the approach as a more reasonable assessor of practical complex structural reliability with safer results.

MicroRNA 34c Gene Down-regulation via DNA Methylation Promotes Self-renewal and Epithelial-Mesenchymal Transition in Breast Tumor-initiating Cells

Yu, Fengyan,Jiao, Yu,Zhu, Yinghua,Wang, Ying,Zhu, Jingde,Cui, Xiuying,Liu, Yujie,He, Yinghua,Park, Eun-Young,Zhang, Hongyu,Lv, Xiaobin,Ma, Kelong,Su, Fengxi,Park, Jong Hoon,Song, Erwei American Society for Biochemistry and Molecular Bi 2012 The Journal of biological chemistry Vol.287 No.1

Modelling, Analysis and Control of Non-linear Kinetics of a Planetary Magnetic Gear Motor for a Steering System

Yang YiFei,Wang RenZhong,Zhu XiaoBin,Du Jie 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

A non-linear mathematical model was built to represent the planetary magnetic gear motor in a vehicle steering system. In view of period doubling, quasi-period and chaotic motions in the steering process of the steering system under some parameters and operation conditions, a numerical simulation analysis was conducted on chaotic behavior arising in the model for the steering system based on the maximum Lyapunov exponent. Furthermore, the system was designed through complementary sliding-mode control and its performance was improved by combining this with an adaptive recurrent cerebellar-modelarticulation controller. This suppresses chaos in the lateral motion of vehicles, and improves the safety and stability of the steering system in the process of vehicle driving, proving the eff ectiveness of the proposed control strategy.

Bias process for heteroepitaxial diamond nucleation on Ir substrates

Wang Weihua,Yang Shilin,Liu Benjian,Hao Xiaobin,Han Jiecai,Dai Bing,Zhu Jiaqi 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Heteroepitaxy is a better method of enlarging SCD wafer size than homoepitaxy. In this work, several aspects of the bias process for heteroepitaxial diamond nucleation are studied experimentally. First, with increasing bias time, the diamond-nucleation pathway is found to transform from “isolated-crystal nucleation” to “typical domain-nucleation” and back to “isolated-crystal nucleation.” An interdependent relationship between bias voltage and bias time is proposed: the higher the bias voltage, the shorter the bias time. Second, a correlation exists between the threshold bias voltage and reactor-chamber pressure: a higher reactor chamber pressure usually requires a higher threshold bias voltage to realize “typical domain nucleation.” Third, diamond bias-enhanced nucleation and growth is observed at a high CH4 content, where the dynamic equilibrium between amorphous-carbon-layer deposition and atomic-hydrogen etching is broken. Finally, epitaxial nucleation is obtained on a substrate with ∅30 mm in a home-made MPCVD setup.