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An efficient approach for the equivalent linearization of frame structures with plastic hinges under nonstationary seismic excitations

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Earthquake engineering and engineering Vibration 2024年第3期23卷 677-690页

作者： Huang Huan li Yingxiong li Yuyu College of water Conservancy and Civil engineering South China Agricultural UniversityGuangzhou 510642China Institute of Smart City and Intelligent transportation Southwest Jiaotong UniversityChengdu 611756China

An efficient approach is proposed for the equivalent linearization of frame structures with plastic hinges under nonstationary seismic *** concentrated plastic hinges,described by the Bouc-Wen model,are assumed to occur at the two ends of a linear-elastic beam *** auxiliary differential equations governing the plastic rotational displacements and their corresponding hysteretic displacements are replaced with linearized differential ***,the two sets of equations of motion for the original nonlinear system can be reduced to an expanded-order equivalent linearized equation of motion for equivalent linear *** solve the equation of motion for equivalent linear systems,the nonstationary random vibration analysis is carried out based on the explicit time-domain method with high ***,the proposed treatment method for initial values of equivalent parameters is investigated in conjunction with parallel computing technology,which provides a new way of obtaining the equivalent linear systems at different time *** on the explicit time-domain method,the key responses of interest of the converged equivalent linear system can be calculated through dimension reduction analysis with high *** examples indicate that the proposed approach has high computational efficiency,and shows good applicability to weak nonlinear and medium-intensity nonlinear systems.

关键词： nonstationary random vibration plastic hinge equivalent linearization method explicit time-domain method parallel computation

MCS-based quantile value approach for reliability-based design of tunnel face support pressure

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Underground Space 2024年第5期18卷 187-198页

作者： Bin li Changxing Wang Hong li Department of Road and Bridge engineering School of Transportation and Logistics EngineeringWuhan University of TechnologyWuhan 430063China Hubei Highway engineering Research Center Wuhan 430063China

This paper develops a new approach for reliability-based design(RBD)of tunnel face support pressure from a quantile value perspective.A surrogate model is constructed to calculate the collapse pressures of the random samples generated by a single run of Monte Carlo simulation(MCS).The cumulative distribution function(CDF)of the collapse pressure is then obtained and the support pressure aiming at a target failure probability is chosen as the upper quantile value of the collapse *** proposed approach does not require repetitive reliability analyses compared to the existing ***,a direct relationship between the target failure probability and the required support pressure is *** illustrative example is used to demonstrate the implementation *** accuracy of the reliability-based support pressures is verified by direct MCS incorporating with three-dimensional numerical ***,the influencing factors,including the sample size of MCS,the correlation coefficient between random variables,the choice of experimental points,and the surrogate model,are *** method can play a complementary role to available approaches due to its advantages of simplicity and efficiency.

关键词： Tunnel face stability Support pressure Reliability-based design Response surface method Monte Carlo simulation

Additives strategies to improving cycling stability of li metal batteries by modifying electrode electrolyte interphases

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Progress in Natural Science:Materials International 2024年第2期34卷 338-344页

作者： Yuan li Pengfei Huang Chunyu Cui Xiaoyuan Ma li Chen Zekun li linhai li Yuhong Tian School of Biological and Chemical engineering Guangxi University of Science and Technology School of College of Chemistry and Chemical engineering Hunan University Isky Future Energy Institute

li metal batteries（LMBs） have attracted much attention due to the ultra-high theoretical capacity of the li metal anode（LMA）.However,the uncontrollable dendrites growth and low coulombic efficiency hinder their practical ***,we explore 3,5-difluoropyridine（2F-BD） as a novel electrolyte additive to enable highperformance *** 2F-BD additive participates in and modifies the solvation structure of li ions by reducing the coordinated number of PF6-at the electrode surface,leading to the formation of a liF and li3N-rich solid electrolyte interphase（SEI）.The liF component increases the robustness of SEI and suppresses the formation of li dendrites,while the li3N component facilitates the transportation and reaction kinetics of li *** a result,the li‖li symmetric cell presents a stable cycling performance of up to 500 h at a current density of 1 mA *** coupling with liFePO4cathode,the obtained full cell achieves high specific capacities of 106.06 mA h g-1and 84.98 mA h g-1at 2.55 mA cm-2and 5.10 mA cm-2,respectively,and maintains a high capacity retention of84.0% after 1000 cycles at 0.13 mA cm-2,with an average cycling CE of 99.58%.

关键词： li metal batteries li dendrites Electrolyte additive

A hybrid nickel/iron-pyromellitic acid electrocatalyst for oxygen evolution reaction

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Nano Research 2024年第4期17卷 2481-2491页

作者： Guoqi li lin li Wenlong li Fusheng li Chunze Yuan Nian Zhang Hui Zhang Tsu-Chien Weng School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Center for Transformative Science ShanghaiTech UniversityShanghai 201210China State Key Lab of Fine Chemicals Institute of Artificial PhotosynthesisDUT-KTH Joint Education and Research Center on Molecular DevicesDalian University of Technology(DUT)Dalian 116024China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China

The migration of protons during the oxygen evolution reaction(OER)is a key factor that affects the performance of OER *** enhance proton transportation,we designed a catalyst based on nickel/iron-pyromellitic acid(NiFe-PMA)prepared by the electrochemical deposition *** catalyst exhibited a low overpotential of 188 mV at a current density of 10 mA·cm^(-2),a Tafel slope of 28.2 mV·dec^(-1),and long-term stability for 30 days with a current of 50 mA·cm^(-2).We characterized the NiFe-PMA catalyst using various techniques,including Fourier transform infrared(FTIR)spectroscopy,Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),transmission electron microscopy(TEM),scanning electron microscopy(SEM),and inductively coupled plasma-optical emission spectrometry(ICP-OES).Our results showed that NiFe-PMA contains nickel,iron atoms,and both coordinated and uncoordinated carboxylate ***,XPS data confirmed that carboxylate ligands could adjust the outer electronic structure of metal ions,resulting in the high valence state of Ni in *** result of XAS indicated that the nickel atoms present in the catalyst might be easier to maintain a higher chemical *** investigations using kinetic isotope effects(KIEs)and proton inventory revealed that the uncoordinated carboxylic protons played a crucial role in receiving protons during the OER,which promoted the proton transfer of the rate-determining step of the *** novel electrocatalysts provide a new strategy for designing more active and cost-effective catalysts for the OER.

关键词： nickel/iron-pyromellitic acid oxygen evolution reaction kinetic isotope effects

Thermal Comfort in Waiting Room at Railway Station in Cold Region in china

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湖南大学学报（自然科学版） 2009年第S1期36卷 66-70页

作者： MA Wei-wu,CHEN Qian-zhou,ZHOU Jie-min,SHI Xiang-nan,li li-qing,WANG Chao,CHEN Zhi-ya(1.School of Energy Science and engineering,Central South university,Changsha,Hunan 410083,china 2.Department of Mechanical engineering,Purdue university,Calumet,Hammond 46323,USA 3.School of Traffic and transportation engineering,Central South university,Changsha,Hunan 410083,china) School of Energy Science and engineering Central South University Changsha 410083 China Department of Mechanical engineering Purdue University Calumet Hammond 46323 United States School of Traffic and transportation engineering Central South University Changsha 410083 China

A field study and analysis about the thermal comfort was carried out in the waiting room at Beijing West Rail Station in Chinese cold ***' TSV(thermal sense vote)was obtained using statistical method on the basis of more than 1 200 *** linear regression between TSV and indoor temperature indicates that thermal neutral temperature is 25.2 ℃.According to the percentage of satisfaction among all passengers under different indoor temperatures,the acceptable temperature range in the waiting room is 24.2～30.2℃.It is also found that passengers' temporary stay should be taken into consideration for the thermal comfort ***' TSV is not a constant value after they enter the waiting *** fact,ΔTSV increases as passengers are waiting for the train,and the growing rate is dependent on indoor-outdoor temperature *** greater the temperature difference,the faster ΔTSV *** last,a linear regression between indoor comfortable temperature and outdoor temperature was generated as the adaptive comfort model.

关键词： waiting room thermal comfort adaptive comfort model

Simplified design of nonlinear damper parameters and seismic responses for long-span cable-stayed bridges with nonlinear viscous dampers

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Frontiers of Structural and Civil engineering 2024年第7期18卷 1103-1116页

作者： Huihui li lifeng li Rui HU Meng YE College of Civil and transportation engineering Shenzhen UniversityShenzhen 518060China Guangdong Provincial Key Laboratory of Durability for Marine Civil engineering Shenzhen UniversityShenzhen 518060China College of Civil engineering Hunan UniversityChangsha 410082China

Viscous dampers are widely used as passive energy dissipation devices for long-span cable-stayed bridges for mitigation of seismic load-induced ***,complicated finite element(FE)modeling,together with repetitive and computationally intensive nonlinear time-history analyses(NTHAs)are generally required in conventional design *** streamline the preliminary design process,this paper developed a simplified longitudinal double degree of freedom model(DDFM)for single and symmetric twin-tower cable-stayed *** on the proposed simplified longitudinal DDFM,the analytical equations for the relevant mass-and stiffness-related parameters and longitudinal natural frequencies of the structure were derived by using analytical and energy *** of the relationship between the nonlinear viscous damper parameters and the equivalent damping ratio was achieved through the equivalent linearization ***,the analytical equations of longitudinal seismic responses for long-span cable-stayed bridges with nonlinear viscous dampers were *** on the developed simplified DDFM and suggested analytical equations,this paper proposed a simplified calculation framework to achieve a simplified design method of nonlinear viscous damper ***,the effectiveness and applicability of the developed simplified longitudinal DDFM and the proposed calculation framework were further validated through numerical analysis of a practical cable-stayed ***,the results indicated the following.1)For the obtained fundamental period and longitudinal stiffness,the differences between results of the simplified longitudinal DDFM and numerical analysis were only 2.05%and 1.5%,respectively.2)Relative calculation errors of the longitudinal girder-end displacement and bending moment of the bottom tower section of the bridge obtained from the simplified longitudinal DDFM were limited to less than 25%.3)The equivalent damping ratio of nonline

关键词： cable-stayed bridges viscous dampers simplified analytical model equivalent damping ratio seismic mitigation

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局部网络的一种结构化设计方法学

系统工程学报 1989年第2期4卷 60-69页

作者：李腊元武汉水运工程学院

本文提出了一种结构化局部网络设计方法学(SDMLN)。它能将一个复杂模糊的局部网络设计工程自顶向下地逐次分解成若干个简单、具体的作业,能精确定义各种需求规范,综合考虑影响局网设计的大量复杂的因素,提供完整清晰的设计文档和最优局... 详细信息

本文提出了一种结构化局部网络设计方法学(SDMLN)。它能将一个复杂模糊的局部网络设计工程自顶向下地逐次分解成若干个简单、具体的作业,能精确定义各种需求规范,综合考虑影响局网设计的大量复杂的因素,提供完整清晰的设计文档和最优局网设计方案。该设计方法学已通过结构分析和设计方法得以实现。研究表明,SDMLN是适应于大型复杂局部网络的一种有效的设计方法学。

关键词：局部网络 SDMLN 系统工程设计方法

Hierarchical model updating for high-speed maglev vehicle/guideway coupled system based on multiobjective optimization

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Frontiers of Structural and Civil engineering 2024年第5期18卷 788-804页

作者： Dexiang li Jingyu Huang College of Civil engineering Tongji UniversityShanghai 200092China National Maglev transportation engineering R&D Center Tongji UniversityShanghai 201804China

The high-speed maglev vehicle/guideway coupled model is an essential simulation tool for investigating vehicle dynamics and mitigating coupled *** improve its accuracy efficiently,this study investigated a hierarchical model updating method integrated with field ***,a high-speed maglev vehicle/guideway coupled model,taking into account the real effect of guideway material properties and elastic restraint of bearings,was developed by integrating the finite element method,multi-body dynamics,and electromagnetic levitation ***,simultaneous in-site measurements of the vehicle/guideway were conducted on a high-speed maglev test line to analyze the system response and structural modal *** the hierarchical updating,an Elman neural network with the optimal Latin hypercube sampling method was used to substitute the FE guideway model,thus improving the computational *** multi-objective particle swarm optimization algorithm with the gray relational projection method was applied to hierarchically update the parameters of the guideway layer and magnetic force layer based on the measured modal parameters and the electromagnet vibration,***,the updated coupled model was compared with the field measurements,and the results demonstrated the model’s accuracy in simulating the actual dynamic response,validating the effectiveness of the updating method.

关键词： high-speed maglev vehicle/guideway coupled model field measurement model updating neural network multi-objective optimization

Design of distributed dynamic absorbers for vibration suppression of panel structures

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Acta Mechanica Sinica 2024年第7期40卷 164-180页

作者： liyuan li Bin li Zehua Xu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China china Aero-Polytechnology Establishment Beijing 100028China

Distributed dynamic absorbers have many advantages such as wide frequency bandwidth for vibration suppression,strong detuning adaptability,and high system stability,making them very suitable for the vibration and noise control of continuous ***,they have broad application prospects in various fields such as transportation,aviation,and ***,there are still many challenges in the engineering applications of distributed dynamic absorbers for vibration suppression,including the engineering realization of the optimal damping of traditional optimal coherence dynamic absorbers,and the engineering applicability of the finite periodic array dynamic *** on the damping material properties obtained by the dynamic mechanical analyzer tests,this paper establishes the finite element model of the cantilever-beam-type dynamic absorber with constrained damping layers,aiming to realize the accurate determination of the optimal *** are conducted by attaching the traditional dynamic absorbers with the optimal damping to a thin-walled panel with four clamped *** show that the vibration of the panel is well suppressed,with the reduction of the frequency response peak larger than 14 dB and the reduction ratio of RMS larger than 58%within 500 ***,the periodically arrayed dynamic absorbers are designed according to the bandgap regulation *** tuning behavior of the arrayed dynamic absorbers by changing designing parameters is *** vibration reduction effect of arrayed dynamic absorbers is compared with that of the traditional dynamic absorbers under the same mass ratio through *** indicate that the arrayed dynamic absorbers are easier to design,and have a similar reduction effect on the modal vibration of the thin panel as the traditional dynamic absorbers within a narrow frequency range near the natural frequency,while they perform unsatisfactory in a broad ***,if t

关键词： Distributed dynamic absorbers engineering realization of the optimal damping Vibration suppression Low-frequency and broadband