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Investigation on dynamic response of liquid-filled cylindrical shellstructures under the action of combined blast and fragments loading
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作者 Zhujie Zhao Hailiang Hou +4 位作者 Dian Li Xiaowei Wu Yongqing Li Zhenghan Chen Linzhi Wu 《Defence Technology(防务技术)》 2025年第7期334-354,共21页
This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabri... This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabricated fragments are employed to examine the damage under blast shock waves and combined blast and fragments loading on various liquid-filled cylindrical shell structures.The test results are compared to numerical calculations and theoretical analysis for the structure's deformation,the liquid medium's movement,and the pressure waves'propagation characteristics under different liquid-filling methods.The results showed that the filling method influences the blast protection and the struc-ture's energy absorption performance.The external filling method reduces the structural deformation,and the internal filling method increases the damage effect.The gapped internal filling method improves the structure's energy absorption efficiency.The pressure wave loading on the liquid-filled cylindrical shell structure differs depending on filling methods.Explosive shock waves and high-speed fragments show a damage enhancement effect on the liquid-filled cylindrical shell structure,depending on the thickness of the internal liquid container layer.The specific impulse on the inner surface of the cylindrical shell positively correlates to the radial deformation of the cylindrical shell structure,and the external liquid layer limits the radial structural deformation. 展开更多
关键词 Blast wave combined blast and fragments loading Filling method Liquid-filled structure Dynamic response
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Mechanical response and impact tendency index correction of gangue-coal combined structure
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作者 WEN Zhi-jie XU Chang-long +2 位作者 GONG Feng-qiang ZUO Yu-jun SONG Zhen-qi 《Journal of Central South University》 2025年第6期2288-2306,共19页
To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with... To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with varying gangue thicknesses and positions.The response patterns of compressive strength,elastic modulus,pre-peak accumulated energy,elastic energy index,and impact energy index were systematically analyzed.Furthermore,a new index for evaluating the impact tendency of gangue-containing coal was proposed,and its effectiveness was verified.The findings are as follows:(1)As the gangue thickness increases,both the compressive strength and the pre-peak energy of the combined structure decrease,whereas the elastic modulus increases accordingly.When the gangue is located in the lower middle position,the combined structure exhibits the lowest compressive strength and elastic modulus but the highest pre peak energy.(2)As the gangue shifts toward the middle position of the combined structure,the failure mode gradually transitions from comple te“crushing”failure to an incomplete“point-type”failure.As gangue thickness further increases,the failure region evolves from overall failure to localized failure,with the degree of failure shifting from complete to incomplete.The K_(crc)value corresponding to“crushing”complete failure is higher and has a stronger impact tendency compared to“point-type”incomplete failure.(3)The proposed comprehensive impact instability evaluation index K_(crc)for the gangue-coal combined structure has shown a significant positive correlation with compressive strength(R_(c))and impact energy index(K_(E)),further verifyi ng its rationality in comprehensively assessing the impact tendency of gangue-containing coal bodies.Applying this index to the evaluation of gangue-containing coal seams provides a more accurate reflection of their impact tendency compared with the residual energy index,which has a wide range of potential applications and practical significance. 展开更多
关键词 gangue-coal combined structure mechanical response peak elastic energy density difference impact tendency comprehensive impact instability index
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Finite element model updating of existing steel bridge based on structural health monitoring 被引量:4
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作者 何旭辉 余志武 陈政清 《Journal of Central South University of Technology》 EI 2008年第3期399-403,共5页
Based on the physical meaning of sensitivity,a new finite element(FE) model updating method was proposed. In this method,a three-dimensional FE model of the Nanjing Yangtze River Bridge(NYRB) with ANSYS program was es... Based on the physical meaning of sensitivity,a new finite element(FE) model updating method was proposed. In this method,a three-dimensional FE model of the Nanjing Yangtze River Bridge(NYRB) with ANSYS program was established and updated by modifying some design parameters. To further validate the updated FE model,the analytical stress-time histories responses of main members induced by a moving train were compared with the measured ones. The results show that the relative error of maximum stress is 2.49% and the minimum relative coefficient of analytical stress-time histories responses is 0.793. The updated model has a good agreement between the calculated data and the tested data,and provides a current baseline FE model for long-term health monitoring and condition assessment of the NYRB. At the same time,the model is validated by stress-time histories responses to be feasible and practical for railway steel bridge model updating. 展开更多
关键词 steel bridge model updating structural health monitoring condition assessment sensitivity
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Analysis of static structural mechanics of vertical axis wind turbine with lift-drag combined starting structures
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作者 QU Chunming FENG Fang +2 位作者 LI Yan BAI Yuedi ZHAO Bin 《排灌机械工程学报》 CSCD 北大核心 2021年第9期923-928,共6页
The finite element analysis was carried out for a composite vertical axis wind turbine with lift-drag combined starting structures to ensure the structure safety of a vertical axis wind turbine(VAWT).The static and mo... The finite element analysis was carried out for a composite vertical axis wind turbine with lift-drag combined starting structures to ensure the structure safety of a vertical axis wind turbine(VAWT).The static and modal analysis of rotor of a composite vertical axis wind turbine was conducted by using ANSYS software.The relevant contour sketch of stress and deformation was obtained.The analysis was made for static structural mechanics,modal analysis of rotor and the total deformation and vibration profile to evaluate the influence on the working capability of the rotor.The analysis results show that the various structure parameters lie in the safety range of structural mechanics in the relative standards.The analysis showing the design safe to operate the rotor of a vertical axis wind turbine.The methods used in this study can be used as a good reference for the structural mechanics′analysis of VAWTs. 展开更多
关键词 vertical axis wind turbine finite element analysis static structural mechanics lift-drag combined starting structure model analysis
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Detached-eddy simulation of flow around high-speed train on a bridge under cross winds 被引量:3
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作者 陈敬文 高广军 朱春丽 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第10期2735-2746,共12页
In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation(DES), a 1/8th scale model of a three-car high-speed train and a typical bridge mod... In order to describe an investigation of the flow around high-speed train on a bridge under cross winds using detached-eddy simulation(DES), a 1/8th scale model of a three-car high-speed train and a typical bridge model are employed, Numerical wind tunnel technology based on computational fluid dynamics(CFD) is used, and the CFD models are set as stationary models. The Reynolds number of the flow, based on the inflow velocity and the height of the vehicle, is 1.9×10~6. The computations are conducted under three cases, train on the windward track on the bridge(WWC), train on the leeward track on the bridge(LWC) and train on the flat ground(FGC). Commercial software FLUENT is used and the mesh sensitivity research is carried out by three different grids: coarse, medium and fine. Results show that compared with FGC case, the side force coefficients of the head cars for the WWC and LWC cases increases by 14% and 29%, respectively; the coefficients of middle cars for the WWC and LWC increase by 32% and 10%, respectively; and that of the tail car increases by 45% for the WWC whereas decreases by 2% for the LWC case. The most notable thing is that the side force and the rolling moment of the head car are greater for the LWC, while the side force and the rolling moment of the middle car and the tail car are greater for the WWC. Comparing the velocity profiles at different locations, the flow is significantly influenced by the bridge-train system when the air is close to it. For the three cases(WWC, LWC and FGC), the pressure on the windward side of train is mostly positive while that of the leeward side is negative. The discrepancy of train's aerodynamic force is due to the different surface area of positive pressure and negative pressure zone. Many vortices are born on the leeward edge of the roofs. Theses vortices develop downstream, detach and dissipate into the wake region. The eddies develop irregularly, leading to a noticeably turbulent flow at leeward side of train. 展开更多
关键词 detached-eddy simulation high speed train bridge cross wind flow structure train aerodynamics
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Structural safety monitoring for Nanjing Yangtze River Bridge 被引量:6
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作者 黄方林 何旭辉 +1 位作者 陈政清 曾储惠 《Journal of Central South University of Technology》 EI 2004年第3期332-335,共4页
In order to evaluate objectively and accurately the integrity, safety and operating conditions in real time for the Nanjing Yangtze River Bridge, a large structural safety monitoring system was described. The monitori... In order to evaluate objectively and accurately the integrity, safety and operating conditions in real time for the Nanjing Yangtze River Bridge, a large structural safety monitoring system was described. The monitoring system is composed of three parts: sensor system, signal sampling and processing system, and safety monitoring and assessment system. Combining theoretical analysis with measured data analysis, main monitoring contents and layout of measuring points were determined. The vibration response monitoring was significantly investigated. The main contents of safety monitoring on vibration response monitoring are vibration of the main body of the Nanjing Yangtze river bridge, collision avoidance of the bridge piers, vibration of girders on high piers for the bridge approach and earthquake. As a field laboratory, the safety monitorying system also provides information to investigate the unknown and indeterminate problems on bridge structures and specific environment around bridges. 展开更多
关键词 structural safety monitoring Nanjing Yangtze river bridge safety monitoring system vibration (response)
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Fatigue damage reliability analysis for Nanjing Yangtze river bridge using structural health monitoring data 被引量:2
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作者 何旭辉 陈政清 +1 位作者 余志武 黄方林 《Journal of Central South University of Technology》 EI 2006年第2期200-203,共4页
To evaluate the fatigue damage reliability of critical members of the Nanjing Yangtze river bridge, according to the stress-number curve and Miner’s rule, the corresponding expressions for calculating the structural ... To evaluate the fatigue damage reliability of critical members of the Nanjing Yangtze river bridge, according to the stress-number curve and Miner’s rule, the corresponding expressions for calculating the structural fatigue damage reliability were derived. Fatigue damage reliability analysis of some critical members of the Nanjing Yangtze river bridge was carried out by using the strain-time histories measured by the structural health monitoring system of the bridge. The corresponding stress spectra were obtained by the real-time rain-flow counting method. Results of fatigue damage were calculated respectively by the reliability method at different reliability and compared with Miner’s rule. The results show that the fatigue damage of critical members of the Nanjing Yangtze river bridge is very small due to its low live-load stress level. 展开更多
关键词 fatigue damage reliability evaluation railway steel bridge structural health monitoring real-time rainflow counting method
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D-S理论和Markov链组合的桥梁性能退化预测研究 被引量:1
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作者 杨国俊 田里 +2 位作者 唐光武 毛建博 杜永峰 《应用数学和力学》 CSCD 北大核心 2024年第4期416-428,共13页
为准确预测桥梁性能退化,考虑到数据随机性和微小扰动发生状态跳跃,提出了一种D-S(Dempster-Shafer)证据理论和Markov链组合的桥梁性能退化组合预测模型和性能退化率的概念.该模型基于指数平滑(exponential smoothing,ES)方法获得新的... 为准确预测桥梁性能退化,考虑到数据随机性和微小扰动发生状态跳跃,提出了一种D-S(Dempster-Shafer)证据理论和Markov链组合的桥梁性能退化组合预测模型和性能退化率的概念.该模型基于指数平滑(exponential smoothing,ES)方法获得新的预测数据序列,并利用Markov链和D-S理论不断进行优化,从而实现桥梁性能退化的组合预测.实际工程的应用结果表明:性能退化率可以直观地表征在梁性能退化的速度.其次,该模型的平均相对误差为1.54%,较于回归、灰色和模糊加权Markov链模型,精度分别提高了1.11%,0.88%和2.8%,而后验差比值为0.242,小于0.35;模型的标准差为9.021,相比其他模型分别减小了3.978,3.405和7.500,而变异系数为0.109,均小于其他模型,验证了组合预测模型在精度和稳定性方面的优越性,可为在役桥梁结构性能退化预测与维护提供理论基础. 展开更多
关键词 桥梁工程 性能退化预测 D-S证据理论 MaRKOV链 组合预测模型 桥梁性能退化率
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二维Hofmann类双金属配合物Cu(DMF)_2[Pt(CN)_4]的合成及晶体结构(英文)
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作者 陆润芹 周虎 袁爱华 《无机化学学报》 SCIE CAS CSCD 北大核心 2010年第2期347-350,共4页
A two-dimensional cyanide-bridged Cu(Ⅱ)-Pt(Ⅱ) bimetallic complex has been synthesized by solution diffusion method using [Pt (CN)4]2- and [Cu (L)]2+ (L =3,10-diethanol-1,3,5,8,10,12-hexaazacyclotetradecane) as build... A two-dimensional cyanide-bridged Cu(Ⅱ)-Pt(Ⅱ) bimetallic complex has been synthesized by solution diffusion method using [Pt (CN)4]2- and [Cu (L)]2+ (L =3,10-diethanol-1,3,5,8,10,12-hexaazacyclotetradecane) as building blocks. Unexpectedly, the obtained complex Cu(DMF)2[Pt(CN)4] (1) is an analogue of the well-known Hofmann -type clathrate without macrocyclic ligand. Single-crystal X-ray diffraction reveals that 1 crystallizes in monoclinic, space group C2/m, a=1.624 8(6) nm, b=0.739 3(3) nm, c=0.695 5(3) nm, β=108.969(4)°. The crystal structure of 1 consists of two-dimensional corrugated metal cyanide sheets without interpenetration stacking along the a axis in an ABAB packing mode. 展开更多
关键词 氰基桥联 大环配体 Hofmann类 晶体结构
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基于InSAR技术的大跨桥梁温度变形监测研究 被引量:1
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作者 周云 危俊杰 +3 位作者 李剑 郝官旺 郑佳缘 朱正荣 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第3期39-50,共12页
以国内某高速铁路钢拱桥为研究对象,选取2017—2018年期间59幅C波段Senti⁃nel-1号雷达卫星影像,利用PS-InSAR技术处理影像获得桥梁的视线向(Line of Sight,LOS)位移,根据SAR成像空间几何关系解算出支座的纵向位移.研究结果表明:支座纵... 以国内某高速铁路钢拱桥为研究对象,选取2017—2018年期间59幅C波段Senti⁃nel-1号雷达卫星影像,利用PS-InSAR技术处理影像获得桥梁的视线向(Line of Sight,LOS)位移,根据SAR成像空间几何关系解算出支座的纵向位移.研究结果表明:支座纵向位移的时空特性与实际桥梁结构相符合,验证了PS-InSAR技术观测桥梁结构位移的可行性.建立支座纵向位移与温度的线性相关模型,并与结构健康监测系统的实测结果进行对比.两者吻合良好,相对误差控制在10%以内,验证了PS-InSAR测量桥梁结构位移的可靠性.利用有限元模拟温度作用下桥梁支座的位移变化,并与PS-InSAR位移时间序列进行对比.两者趋势基本一致,LOS向位移误差在[-10,10]mm,验证了PS-InSAR测量桥梁结构位移的准确性. 展开更多
关键词 结构健康监测 PS-INSaR 大跨桥梁结构 有限元方法 温度变形监测
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基于改进Faster R-CNN与U-Net算法的桥梁病害识别与量化方法 被引量:6
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作者 乔朋 梁志强 +3 位作者 段长江 马晨 王思龙 狄谨 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第3期627-638,共12页
为实现桥梁病害检测的自动化,对基于图像处理技术的混凝土桥梁表观病害的智能识别和尺寸确定方法展开研究.提出基于改进Faster R-CNN算法的病害识别方法,利用K均值聚类和遗传算法对区域候选网络锚框进行优化设计;以裂缝预测区域为基础,... 为实现桥梁病害检测的自动化,对基于图像处理技术的混凝土桥梁表观病害的智能识别和尺寸确定方法展开研究.提出基于改进Faster R-CNN算法的病害识别方法,利用K均值聚类和遗传算法对区域候选网络锚框进行优化设计;以裂缝预测区域为基础,提出ResNet34结合U-Net的裂缝形态提取方法,并结合裂缝形态学研究了裂缝像素宽度和长度的确定方法.结果表明:锚框优化设计可改进Faster R-CNN算法的表观病害识别效果,5类常见病害的预测准确率、召回率、平均精确率分别由68.40%、69.87%、74.64%提升到85.40%、83.59%、83.72%;利用病害预测框,结合改进U-Net算法的裂缝像素尺寸计算,可实现裂缝病害尺寸的自动测量;基于改进Faster R-CNN和改进U-Net的方法可实现混凝土桥梁常见病害的智能识别和尺寸量化,从而提高桥梁病害检测效率并促进桥梁技术状况评定的智能化. 展开更多
关键词 桥梁工程 表观病害识别 裂缝尺寸确定 改进Faster R-CNN 改进U-Net
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基于Halbach阵列轴向式电涡流阻尼器性能提升
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作者 朱前坤 梁玉坤 +1 位作者 王宪玉 杜永峰 《振动与冲击》 EI CSCD 北大核心 2024年第22期45-52,共8页
为了提高轴向式电涡流阻尼器的阻尼性能,引入Halbach阵列,建立了Halbach阵列轴向式电涡流阻尼器(Halbach array axial eddy current damper,HAECD)模型。首先,阐明了HAECD的整体构造、工作原理与力学特性,采用三维电磁场有限元瞬态分析... 为了提高轴向式电涡流阻尼器的阻尼性能,引入Halbach阵列,建立了Halbach阵列轴向式电涡流阻尼器(Halbach array axial eddy current damper,HAECD)模型。首先,阐明了HAECD的整体构造、工作原理与力学特性,采用三维电磁场有限元瞬态分析方法验证电涡流单元阻尼系数计算的准确性;然后,建立四种阵列方式的电涡流阻尼单元计算模型并进行了优化分析;最后,分析了永磁体厚度、磁化角度及磁极配比对HAECD阻尼系数的影响。研究结果表明:Halbach阵列相较于其他阵列方式,在同等磁体体积情况下的阻尼系数提升率最高可达59.2%;针对本装置,适当增加永磁体厚度能有效提升阻尼系数,最优磁体厚度为31 mm;当磁化角度为2°时,阻尼系数最大;阻尼系数随着磁极配比的增大而逐渐缓慢增加,当磁极配比为2.5时,阻尼性能最优。 展开更多
关键词 桥梁结构 振动控制 阵列优化 参数分析 HaLBaCH阵列
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基于滑窗OPTICS算法和DATA-SSI算法的桥梁模态参数智能化识别
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作者 陈永高 钟振宇 罗晓峰 《振动与冲击》 EI CSCD 北大核心 2024年第7期18-29,共12页
针对现有基于数据驱动的随机子空间(data-driven stochastic subspace identification,DATA-SSI)算法存在的不足,无法实现稳定图中真假模态的智能化筛选,提出了一种新的模态参数智能化识别算法。首先通过引入滑窗技术来实现对输入信号... 针对现有基于数据驱动的随机子空间(data-driven stochastic subspace identification,DATA-SSI)算法存在的不足,无法实现稳定图中真假模态的智能化筛选,提出了一种新的模态参数智能化识别算法。首先通过引入滑窗技术来实现对输入信号的合理划分,以避免虚假模态和模态遗漏现象的出现;其次通过引入OPTICS(ordering points to identify the clustering structure)密度聚类算法实现稳定图中真实模态的智能化筛选,最后将所提算法运用于某实际大型斜拉桥主梁结构的频率和模态振型识别过程中。结果表明,所提改进算法识别的频率值结果与理论值(MIDAS有限元结果)以及实际值(现场动力特性实测结果)间的误差均在5%以内,且识别的模态振型图与理论模态振型图具有很高的相似性。 展开更多
关键词 桥梁结构 随机子空间(SSI) 滑窗原理 密度聚类算法 稳定图
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基于EDA统计图量化的桥梁动态监测数据质量评估
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作者 殷鹏程 谭曼丽莎 +1 位作者 曹阳梅 单德山 《重庆交通大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第5期9-16,共8页
探索性数据分析统计图在桥梁健康监测动态数据质量评估中已有广泛应用。为了减少人工观察统计图的主观性,通过近似度量方法实现统计图的量化分析,得到多个指标对监测数据进行快速质量评估。在运营环境激励作用下,桥梁结构动力响应具有... 探索性数据分析统计图在桥梁健康监测动态数据质量评估中已有广泛应用。为了减少人工观察统计图的主观性,通过近似度量方法实现统计图的量化分析,得到多个指标对监测数据进行快速质量评估。在运营环境激励作用下,桥梁结构动力响应具有短时线性平稳性,近似服从正态分布。以某大跨斜拉桥振动数据为研究对象,首先,绘制样本数据直方图和Q-Q图,通过观察数据分布特征预先判断数据质量,确定优、良和差3个等级。然后,分别通过KL散度和余弦相似度2种近似度量方法对样本数据直方图和Q-Q图进行量化,得到数据服从正态分布程度的指标;通过箱线图检测样本数据全局异常点,得到正常数据占比;统计分析得到量化值和先验质量等级的对应关系,确定以直方图KL散度和余弦相似度为主、以箱线图正常数据占比为辅的数据质量评估标准。最后,取部分数据为验证集,进一步验证所提方法各个指标的合理性,并给出该方法在实际工程上的应用结果。 展开更多
关键词 桥梁工程 桥梁结构健康监测 数据质量评估 探索性数据分析 KL散度 余弦相似度 箱线图
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Design method of pile-slab structure roadbed of ballastless track on soil subgrade 被引量:5
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作者 ZHAN Yong-xiang YAO Hai-lin JIANG Guan-lu 《Journal of Central South University》 SCIE EI CAS 2013年第7期2072-2082,共11页
Pile-slab structure roadbed is a new form of ballastless track for high speed railway. Due to lack of corresponding design code, based on the analysis of its structure characteristics and application requirements, it ... Pile-slab structure roadbed is a new form of ballastless track for high speed railway. Due to lack of corresponding design code, based on the analysis of its structure characteristics and application requirements, it is proposed to carry out load effect combination according to ultimate limit state and serviceability limit state, and the most unfavorable combination of each state is chosen to carry through design calculation for pile-slab structure. Space model of pile-slab structure can be simplified as a plane flame model, by using the orthogonal test method, and the design parameter of pile-slab structure is optimized. Moreover, based on the engineering background of Suining-Chongqing high-speed railway, the dynamic deformation characteristics of pile-slab structure roadbed are further researched by carrying on the indoor dynamic model test. The test results show that the settlement after construction of subgrade satisfies the requirement of settlement control to build ballastless track on soil subgrade for high-speed railway. Slab structure plays the role of arch shell as load is transmitted from slab to pile, and the vertical dynamic stress of subgrade soil is approximately of "K" form distribution with the depth. The distribution of pile stress is closely related to soil characteristics, which has an upset triangle shape where the large dynamic stress is at the top. Pile compared with soil shares most dynamic stress. Pile structure expands the depth of the dynamic response of subgrade has limited effect on dynamic response. These results can provide subgrade. and improves the stress of subgrade soil, and the speed of train scientific basis for pile-slab structure roadbed used on soil 展开更多
关键词 soil subgrade ballastless track pile-slab structure roadbed load combination dynamic model test
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Rock bridge slice element method in slope stability analysis based on multi-scale geological structure mapping
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作者 张发明 汪北华 +2 位作者 陈祖煜 汪小刚 贾志欣 《Journal of Central South University》 SCIE EI CAS 2008年第S2期131-137,共7页
The searching method of failure surface which consists of complex geological structures in high and steep rock slopes was studied. Based on computer simulation technology and Monte-Carlo method, three dimensional mult... The searching method of failure surface which consists of complex geological structures in high and steep rock slopes was studied. Based on computer simulation technology and Monte-Carlo method, three dimensional multi-scale geological structures such as engineering scale and statistical scale structures of the slope were simulated. The searching method of failure route which consists of joints and rock bridges was determined via simulation annealing method by considering the shear strength of joints or rock bridges in one supposed route. When shear strengths of all the supposed routes were computed, the least shear strength route was considered failure route. Then, the inclined slice of joint slices and rock bridge slices were separated according to the position of joints and rock bridges. For the rock bridge slices, by distinguishing the failure model, the force direction to the next slice was defined. Finally, the limit equilibrium equations for every slice were established, and the slope stability factor was obtained. One practical example indicates that the discussed method is more closely to the real condition. 展开更多
关键词 ROCK SLOPE three dimensional GEOLOGICaL structure ROCK bridge SLICE element method stability
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基于响应面法和ARO算法的桥梁有限元模型修正 被引量:1
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作者 杨宏印 姜良维 +2 位作者 顾箭峰 曹鸿猷 吴楠昊 《重庆交通大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第9期9-17,共9页
针对桥梁结构模型修正过程中计算量大、全局寻优难等问题,提出一种基于响应面法和人工兔优化算法(artificial rabbits optimization, ARO)的桥梁有限元模型修正方法。该方法通过F检验法明确对结构响应影响显著的参数并建立响应面模型作... 针对桥梁结构模型修正过程中计算量大、全局寻优难等问题,提出一种基于响应面法和人工兔优化算法(artificial rabbits optimization, ARO)的桥梁有限元模型修正方法。该方法通过F检验法明确对结构响应影响显著的参数并建立响应面模型作为桥梁有限元模型的代理模型进行迭代计算,然后通过静动力联合修正法基于特征响应的响应面模型计算值和试验值构建目标函数,并通过人工兔优化算法对目标函数进行迭代计算进而获得精确的有限元模型参数。采用该方法对变截面连续刚构黄河特大桥有限元模型进行修正,结果显示:基于显著性分析结果建立的桥梁响应面模型相关系数大于0.98,且平均绝对误差低于0.05;模型修正后主梁关键截面竖向位移最大相对误差由32.97%降至5.72%,平均相对误差由20.67%降至3.61%,桥梁前3阶竖向自振频率平均相对误差仅为0.18%。可见,采用所提方法修正的模型能用于评价桥梁结构实际受力性能。 展开更多
关键词 桥梁工程 变截面连续刚构桥 有限元模型修正 F检验法 响应面法 静动力联合修正法
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CoFeMgAl-LDHs/CNTs复合材料对水泥水化及微观结构的影响 被引量:3
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作者 廖牧情 熊志文 +3 位作者 柯国军 邹品玉 宋百姓 金丹 《硅酸盐通报》 CAS 北大核心 2022年第1期3-12,共10页
通过进行水化热测试、非蒸发水含量测试、X射线衍射分析、扫描电镜分析、压汞测试及强度试验,研究了钴铁镁铝水滑石-碳纳米管复合材料(CoFeMgAl-LDHs/CNTs)对水泥水化过程、硬化水泥净浆孔结构及强度的影响。结果表明,CoFeMgAl-LDHs/CNT... 通过进行水化热测试、非蒸发水含量测试、X射线衍射分析、扫描电镜分析、压汞测试及强度试验,研究了钴铁镁铝水滑石-碳纳米管复合材料(CoFeMgAl-LDHs/CNTs)对水泥水化过程、硬化水泥净浆孔结构及强度的影响。结果表明,CoFeMgAl-LDHs/CNTs复合材料通过成核作用显著提升了水泥3 d内的水化程度,从而显著提高了水泥净浆3 d内的抗压强度,3 d后强度提高效果逐渐减小,7 d后复合材料对硬化水泥浆体强度没有明显的提高作用。掺入CoFeMgAl-LDHs/CNTs复合材料的水泥净浆与空白净浆相比,胶凝孔和毛细孔含量明显增多,大孔含量有所降低,同时复合材料的桥联作用进一步优化了水泥净浆的微观结构,从而提高了水泥基体薄弱部位的应力承载能力。因此在同一龄期,复合材料掺入后硬化水泥净浆的强度有所增大。由于复合材料掺量的变化对孔径分布没有明显的影响,改变复合材料的掺量对同龄期硬化水泥净浆强度提升影响较小。 展开更多
关键词 钴铁镁铝水滑石-碳纳米管 水泥净浆 水化 孔结构 强度 成核作用 桥联作用
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基于ANSYS Workbench的联合收获机滚筒轴疲劳强度分析与优化 被引量:1
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作者 陈旭 徐磊鑫 +3 位作者 王万章 解文东 袁玲合 何勋 《农业装备与车辆工程》 2024年第2期1-7,共7页
切纵轴流谷物联合收获机脱粒能力强、工作效率高,是未来收获行业的发展趋势。联合收获机在作业的过程中由于喂入量不稳定、物料层不均匀使得切流脱粒滚筒所受的交变载荷冲击较大,造成滚筒轴断裂。采用ANSYS Workbench对滚筒轴进行静力... 切纵轴流谷物联合收获机脱粒能力强、工作效率高,是未来收获行业的发展趋势。联合收获机在作业的过程中由于喂入量不稳定、物料层不均匀使得切流脱粒滚筒所受的交变载荷冲击较大,造成滚筒轴断裂。采用ANSYS Workbench对滚筒轴进行静力学和疲劳强度分析,得到实际作业过程中导致滚筒轴断裂失效的原因为疲劳断裂,然后对轴的结构和材料进行改进,改进后的轴最大应力值减小至原来的40.6%左右,疲劳寿命循环次数有了极大的提高,有效保障了联合收获机长时间的安全作业。 展开更多
关键词 联合收获机 切流滚筒轴 静力学分析 疲劳分析 结构优化
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Pt25Rh/TaC界面特性的第一性原理研究
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作者 左元华 于晓华 +5 位作者 荣菊 冯晶 张志伟 魏燕 蔡宏中 胡昌义 《原子与分子物理学报》 北大核心 2024年第5期144-152,共9页
铂铑(PtRh)合金具有优良的高温力学性能,是目前最具潜力的航天发动机推力器喷管材料之一.研究表明,进一步提升PtRh合金的高温性能,能有效延长航天飞行器的服役寿命.本研究利用第一性原理、Materials Studio软件,研究了TaC热障涂层与Pt2... 铂铑(PtRh)合金具有优良的高温力学性能,是目前最具潜力的航天发动机推力器喷管材料之一.研究表明,进一步提升PtRh合金的高温性能,能有效延长航天飞行器的服役寿命.本研究利用第一性原理、Materials Studio软件,研究了TaC热障涂层与Pt25Rh高温合金的界面特性和结合机制.结果表明,TaC的热膨胀系数与Pt25Rh较为接近,比同类热障涂层具有更优的界面匹配性和结合力,既可作为单独的防护层使用,也可作为粘结层使用.此外,由于Ta-C,Pt-C和Rh-C键的电荷转移能力均强于Ta-Pt和Ta-Rh键,TaC与Pt25Rh合金的最稳定结合位置为孔位的Pt25Rh(111)/TaC(111)C,其界面粘附功为6.202 J/m^(2).本研究可为PtRh合金的热防护提供借鉴. 展开更多
关键词 高温合金 热障涂层 第一性原理 界面结构 结合机制
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