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Field survey and analysis on near-fault severely damaged high-speed railway bridge in 2022 M6.9 Menyuan earthquake

Earthquake Engineering and Engineering Vibration 2024年第4期23卷 1043-1055页

作者： Lin Xuchuan Liu Fuxiang shan wenchen Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China Institute of Smart City and Intelligent Transportation Southwest Jiaotong UniversityChengdu610000China

The 2022 M6.9 Menyuan earthquake caused severe damage to a high-speed railway bridge,which was designed for high-speed trains running at speeds of above 250 km/h and is located right next to the *** of this type have been widely used for rapidly constructing the high-speed railway network,but few bridges have been tested by near-fault devastating *** potential severe impact of the earthquake on the high-speed railway is not only the safety of the infrastructure,trains and passengers,but also economic loss due to interrupted railway ***,a field survey was carried out immediately after the earthquake to collect time-sensitive *** damage to the bridge was carefully investigated,and quantitative analyses were conducted to better understand the mechanism of the bridge *** was found that seismic action perpendicular to the bridge’s longitudinal direction caused severe damage to the girders and rails,while none of the piers showed obvious deformation or *** maximum values of transverse displacement,out-of-plane rotation and twisting angle of girders reached 212.6 cm,3.1 degrees and 19.9 degrees,respectively,causing severe damage to the bearing supports and anti-seismic retaining *** observations provide a basis for improving the seismic design of high-speed railway bridges located in near-fault areas.

关键词： Menyuan earthquake field survey high-speed railway bridge near fault seismic damage

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Multi-population particle swarm optimization algorithm for automatic design of steel frames

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 89-103页

作者： wenchen shan Jiepeng LIU Yao DING Y.Frank CHEN Junwen ZHOU Institute of Smart City and Intelligent Transportation Southwest Jiaotong UniversityChengdu 610000China School of Civil Engineering Chongqing UniversityChongqing 400045China Department of Civil Engineering the Pennsylvania State UniversityMiddletownPA 17057USA

Steel structures are widely used;however,their traditional design method is a trial-and-error procedure which is neither efficient nor cost ***,a multi-population particle swarm optimization(MPPSO)algorithm is developed to optimize the weight of steel frames according to standard design *** are made to improve the algorithm performances including the constraint-based strategy,piecewise mean learning strategy and multi-population cooperative *** proposed method is tested against the representative frame taken from American standards and against other steel frames matching Chinese design *** related parameter influences on optimization results are *** the representative frame,MPPSO can achieve greater efficiency through reduction of the number of analyses by more than 65% and can obtain frame with the weight for at least 2.4%lighter.A similar trend can also be observed in cases subjected to Chinese design *** addition,a migration interval of 1 and the number of populations as 5 are recommended to obtain better MPPSO *** purpose of the study is to propose a method with high efficiency and robustness that is not confined to structural scales and design *** aims to provide a reference for automatic structural optimization design problems even with dimensional *** proposed method can be easily generalized to the optimization problem of other structural systems.

关键词： steel frame multi-population particle swarm optimization automatic structural optimization design

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Ultrastructural changes of penile tunica albuginea in diabetic rats

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Asian Journal of Andrology 2004年第4期6卷 365-368页

作者： Ying-LiLu Zhou-JunShen HuaWang shan-wenchen Xie-LaiZhou Zhao-DianChen DepartmentofEndocrinology SirRunRunShawHospital DepartmentofUrology FirstAffiliatedHospitalSchoolofMedicineZhejiangUniversityHangzhou310016China

Aim: To clarify the ultrastructural changes of penile tunica albuginea (TA) in streptozotocin (STZ)-induced diabetic rats. Methods: Intraperitoneal injection of STZ was used to induce diabetes mellitus (DM) in 12 Sprague Dawley rats. Ten rats (age and weight-matched) were used as control. Blood samples from the tail snips of the rats were used for the determination of serum glucose levels with SureStep Plus Blood Meter. At week 4 and 10 after the injection, half of the rats in each group were sacrificed and penile samples were obtained from the middle third of the penile shaft for the examination of TA under scanning electron microscopy. Results: In the diabetic group, the serum glucose levels were higher (P<0.01 at both time points) and the TA were thinner (P<0.05) than those of the controls. In the control group, the fibers of TA were rich and arranged regularly and undulated, while in the diabetic group, the fibers were diminished, lost the undulations and were arranged irregularly. Conclusion: In rats, DM appeared to impair the penile TA ultrastructures and this impairment could contribute to diabetic erectile dysfunction in part by impairing the veno-occlusive function.

关键词： tunica albuginea penis diabetes mellitus scanning electron microscopy

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Hot spinning of cylindrical workpieces of TA15 titanium alloy

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Rare Metals 2007年第S1期26卷 255-261页

作者： XU wenchen,shan Debin,YANG Guoping,CHEN Yu,LU Yan,and KANG Dachang School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

In order to form large-diameter thin-wall cylindrical workpieces of TA15 titanium alloy,tube hot spinning experiments of the alloy were conducted on a CNC hot spinning *** causes of some forming defects occuring in hot spinning,such as crack,pileup,bulge and corrugation,were analyzed and the corresponding measures were put forward to avoid spinning defects,based on which a proper process scheme of hot spinning of TA15 alloy was obtained and the large-diameter and thin-walled cylindrical workpieces were formed with good *** results show that spinning temperature has distinct influence on forming quality of spun *** range of spinning temperature determines the spinnability of titanium alloy and the ununiformity of temperature distribution near the deformation zone leads to the formation of *** reasonable heating method is that the deforming region is heated to the optimum temperature range of 600-700 ℃,the deformed region is heated continuously and a certain length of undeformed region is *** the thickness-to-diameter ratio(t/D) of spun workpiece reducing to certain value(t/D<1%),surface bulge and corrugation is rather easier to come into being,which could be controlled through restraining diameter growth and employing smaller reduction rate and lower temperature in the optimum spinning temperature range.

关键词： TA15 titanium alloy hot spinning cylindrical workpiece forming defect thickness-to-diameter ratio

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Preliminary study on androgen dependence of calcitonin gene-related peptide in rat penis

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Asian Journal of Andrology 2005年第1期7卷 55-59页

作者： Zhou-JunShen shan-wenchen Ying-LiLu Liao-YuanLi Xie-LaiZhou Ming-GuangZhang Zhao-DianChen DepartmentofUrology FirstAffiliatedHospitalSchoolofMedicineZhejiangUniversityHangzhou310003China DepartmentofEndocrinology SirRunRunShawHospitalSchoolofMedicineZhejiangUniversityHangzhou310003China

Aim: To study the androgen dependence of the neurotransmitter, calcitonin gene-related peptide (CGRP) in rat penis. Methods: Forty-four Sprague-Dawley rats were randomly divided into Group A (intact controls), Group B (castrated) and Group C (gavaged with finasteride 4.5 mg·kg^(-1).day^(-1)). Four and ten weeks later respectively, half of rats in each group were anaesthetized. Blood samples were taken for the measurement of serum testosterone and dihydrotestosterone (DHT) by means of radioimmunoassay. Penile samples were harvested for the investigation of calcitonin gene related peptide (CGRP)-immunoreactive nerve fibers with immunohistochemistry. The computer-assisted imaging analysis system was applied to calculate the area proportion of the CGRP-positive nerve fibers (CGRP-PNF) in each group. Results: 1) Both 4 and 10 weeks later, testosterone and DHT levels in Group B decreased significantly compared with those in Group A, (P 0.05); However, 10 weeks later, the proportion of CGRP-PNF in Groups B and C was significantly less than that in Group A (P < 0.01);3) The proportion of CGRP-PNF of 4-week animals in Groups B and C was significantly higher than that of 10-week animals (P < 0.05). Conclusion: The expression of neurotransmitter, CGRP may depend on androgens, including testosterone and DHT in rat penis.

关键词： neurotransmitters calcitonin gene-related peptide androgens penis rats

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斜钢管混凝土柱框架-核心筒-伸臂桁架结构抗震性能研究

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建筑结构学报 2023年第6期44卷 12-23页

作者：成宇刘界鹏单文臣李江重庆大学山地城镇建设与新技术教育部重点实验室重庆400045 重庆大学土木工程学院重庆400045 深圳大学土木与交通工程学院广东深圳518060

为明确钢管混凝土(CFT)柱框架-核心筒-伸臂桁架混合结构的抗震性能,结合典型工程“青岛海天中心”,采用MARC有限元软件对该结构体系进行抗震性能分析。分别进行了多遇地震、设防地震及罕遇地震作用下的弹塑性动力时程分析。结果表明:设... 详细信息

为明确钢管混凝土(CFT)柱框架-核心筒-伸臂桁架混合结构的抗震性能,结合典型工程“青岛海天中心”,采用MARC有限元软件对该结构体系进行抗震性能分析。分别进行了多遇地震、设防地震及罕遇地震作用下的弹塑性动力时程分析。结果表明:设置斜CFT框架柱可有效控制结构顶点位移,罕遇地震作用下,最大顶点位移较直CFT框架柱结构的降低约76.6%;斜CFT柱使地震剪力由核心筒向框架转移,转移后的地震剪力更接近双重抗侧力体系的设计要求,即在多遇地震作用下框架部分至少承担结构总底部剪力的20%;同时,结构倾覆力矩的变化与剪力相反。设置斜CFT框架柱的结构可充分利用材料性能,在发挥相同抗侧力作用情况下能取得较好的经济效益。在此基础上,对结构进行基于增量动力分析(IDA)的地震倒塌易损性分析,确定了结构塑性发展路径为连梁、核心筒底部、框架柱底端、伸臂桁架。易损性分析结果表明,CFT框架柱斜置未对结构抗震倒塌安全储备产生不利影响,依然表现出优异的抗地震倒塌能力;结构变截面楼层部分的连梁和周围墙底塑性损伤最为严重,在设计中应对其进行加强。

关键词：超高层建筑框架-核心筒-伸臂桁架结构斜钢管混凝土框架柱增量动力分析抗震性能

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支撑巨型框架-核心筒结构体系抗震性能研究

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建筑结构学报 2021年第1期42卷 75-83页

作者：周绪红单文臣刘界鹏林旭川傅学怡重庆大学土木工程学院重庆400045 中国地震局工程力学研究所黑龙江哈尔滨150080 深圳大学土木与交通工程学院广东深圳518060

以深圳平安金融中心为原型结构,提出支撑巨型框架-核心筒结构体系的概念,并以目前超高层常用的巨型框架-核心筒-伸臂桁架结构体系作为参照,开展了结构体系的抗震性能对比研究。研究结果表明,在两种结构体系抗侧刚度相近的工况下,支撑巨... 详细信息

以深圳平安金融中心为原型结构,提出支撑巨型框架-核心筒结构体系的概念,并以目前超高层常用的巨型框架-核心筒-伸臂桁架结构体系作为参照,开展了结构体系的抗震性能对比研究。研究结果表明,在两种结构体系抗侧刚度相近的工况下,支撑巨型框架-核心筒结构体系的用钢量显著降低。罕遇地震作用下,该结构体系的典型屈服路径为核心筒→巨柱→支撑→伸臂桁架。该结构体系显著增强了外框的抗侧刚度,提高了外框的剪力分担比例,使得内筒和外框的抗侧能力更加均衡,同时内筒和外框之间的竖向剪力连接需求降低,既减轻了核心筒损伤,又可降低伸臂桁架的刚度和杆件截面面积,并使伸臂桁架加强层与相邻上下层之间的层间刚度突变效应显著降低。因此,支撑巨型框架-核心筒结构体系是一种抗震性能优越的混合结构体系,适用于500 m左右及以上高度的超高层结构。

关键词：超高层建筑支撑巨型框架-核心筒结构体系弹塑性时程分析抗震性能

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CFT框架-RC剪力墙结构基于一致倒塌风险的抗震设计研究

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土木工程学报 2022年第8期55卷 26-34页

作者：单文臣周绪红林旭川呼辉峰相瀛昌重庆大学重庆400045 中国地震局工程力学研究所黑龙江哈尔滨150080

我国CFT框架-RC剪力墙结构通常按照双重抗侧力体系进行设计。与一般RC框架相比,在相同竖向承载力条件下的截面尺寸和抗弯刚度较小,按双重抗侧力体系设计将影响结构的经济性能和建筑功能。因此,文章根据我国规范设计了典型的CFT框架-RC... 详细信息

我国CFT框架-RC剪力墙结构通常按照双重抗侧力体系进行设计。与一般RC框架相比,在相同竖向承载力条件下的截面尺寸和抗弯刚度较小,按双重抗侧力体系设计将影响结构的经济性能和建筑功能。因此,文章根据我国规范设计了典型的CFT框架-RC剪力墙双重抗侧力体系结构模型,采用一致倒塌风险的抗震设计方法中对单重抗侧力体系设计的要求,设计了相应的CFT框架-RC剪力墙单重抗侧力体系结构模型,并对比分析了单重和双重抗侧力体系在不同水准地震作用下的结构响应和罕遇地震结构倒塌概率和抗地震倒塌安全储备。结果表明,与双重抗侧力体系相比,单重抗侧力体系结构的地震响应和大震倒塌概率相近,均满足“大震不倒”抗震要求,而单重抗侧力体系的结构抗地震倒塌安全储备较大,且用钢量较少。

关键词： CFT框架-RC剪力墙结构增量动力分析单重抗侧力体系一致倒塌风险抗倒塌安全储备系数

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Effect of power spinning and heat treatment on microstructure evolution and mechanical properties of duplex low-cost titanium alloy

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Journal of Materials Science & Technology 2023年第5期136卷 121-139页

作者： Zhongze Yang wenchen Xu Weiqing Zhang Yu Chen Debin shan National Key Laboratory for Precision Hot Processing of Metals&School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

The microstructural evolution and mechanical properties of low-cost Ti-5.5Al-1Fe-3.5Cr-3.2Zr-0.2Si al-loy during power spinning and after three types of heat-treatment routines(low-temperature anneal-ing,high-temperature annealing,solution and annealing)were systematically *** effective heat-treatment routine to fabricate high-strength and acceptable ductile as-spun Ti-5.5Al-1Fe-3.5Cr-3.2Zr-0.2Si alloy tubes was then proposed whereby the relationship between the mechanical performances and mi-crostructures was ***{0002}_(α)and{001}_(β)textures were formed after multi-pass power *** as-spun LC-Ti alloy exhibited a good combination of strength and elongation after heat treat-ment at 550℃for 4 h,which was ascribed to the large plastic induced low-temperature spheroidization of deformedαphase and nanoscaleαprecipitation from deformedβ***,the elongation de-creased evidently when Zr2Si/TiCr2 participated at the interphase boundaries after heat treatment at 550℃for 8 *** high-temperature annealing,the elongation changed nonlinearly owing to the precipitation of Zr2Si particles at triangular grain boundaries treated at 750℃for 1 h,and the spheroidization of the deformedα_(p)*** solution and annealing conditions,lenticularαs would participate from the metastableβgrains,which contributed to the greatest strength albeit poor *** study provides an effective guidance for the processing and application of the low-cost titanium alloy.

关键词： Low-cost titanium alloy Power spinning Heat treatment Microstructure evolution Mechanical property

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Analysis of abnormal texture formation and strengthening mechanism in an extruded Mg-Gd-Y-Zn-Zr alloy

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Journal of Materials Science & Technology 2020年第10期42卷 133-145页

作者： Xueze Jin wenchen Xu Zhongze Yang Can Yuan Debin shan BugangTeng Bo Cheng Jin National Key Laboratory for Precision Hot Processing of Metals&School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Advanced Composites Simulation Lab University of Southern CaliforniaLos AngelesCA 90089-0241USA

A Mg-Gd-Y-Zn-Zr magnesium alloy with different initial states was extruded under different extrusion *** effect of solution treatment and extrusion parameters on the microstructure,texture and mechanical properties were analyzed in detail,and the abnormal texture formation and strengthening mechanism was *** extruded at low temperature and small extrusion ratio,the bimodal microstructure consisting of fine dynamically recrystallized grains and coarse deformed grains occurred both in the as-cast alloy and solution-treated *** the extrusion temperature and extrusion ratio were increased,the amount and size of dynamically recrystallized grains increased and the grain size of the solution-treated alloy showed higher growth ***,an abnormal texture withparallel with extrusion direction developed due to the occurrence of non-basal slip and continuous dynamic *** could be enhanced by solution treatment,high temperature,and large extrusion *** the as-cast alloy and solution-treated alloy exhibited the highest tensile strength after extrusion at 300℃with an extrusion ratio of *** refinement was the main strengthening mechanism utilized in both the as-cast alloy and the solution-treated *** hardening played an important role in the sample extruded at low temperature and small extrusion ratio,with the highest contribution of about 33 MPa after extrusion at 300℃with an extrusion ratio of *** strengthening contributed more in the sample extruded at high temperature and large extrusion ratio,but no more than 24.1 *** strengthening was another strengthening mechanism in the extruded as-cast alloy,especially at high temperature and large extrusion ratio(no more than 9 MPa).

关键词： Hot extrusion Heat treatment Abnormal texture Strengthening mechanism Quantitative analysis

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