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Failure behavior of rock and steel slag cemented paste backfill composite structures under uniaxial compression:Effects of interface angle and steel slag content
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作者 HAO Jian-shuai ZHOU Zi-han +1 位作者 CHEN Zhong-hui CHE Zeng-hui 《Journal of Central South University》 2025年第7期2679-2695,共17页
The stability of the“surrounding rock-backfill”com posite system is crucial for the safety of mining stopes.This study systematically investigates the effects of steel slag(SS)content and interface angle on the stre... The stability of the“surrounding rock-backfill”com posite system is crucial for the safety of mining stopes.This study systematically investigates the effects of steel slag(SS)content and interface angle on the strength and failure characteristics of rock and SS-cemented paste backfill composite specimens(RBCS)through uniaxial compression strength tests(UCS),acoustic emission systems(AE),and 3 D digital image correlation monitoring technology(3 D-DIC).The intrinsic mechanism by which SS content influences the strength of SS-CPB was revealed through an analysis of its hydration reaction degree and microstructural characteristics under varying SS content.Moreover,a theoretical strength model incorporating different interface angles was developed to explore the impact of interface inclination on failure modes and mechanical strength.The main conclusions are as follows:The incorporation of SS enhances the plastic characteristics of RBCS and reduces its brittleness,with the increase of SS content,the stress-strain curve of RBCS in the“staircase-like”stag e becomes smoother;When the interface angle is 45°,the RBCS stress-strain curve exhibits a bimodal feature,and the failure mode changes from Y-shaped fractures to interface and axial splitting;The addition of SS results in a reduction of hydration products such as Ca(OH)_(2) in the backfill cementing system and an increase in harmful pores,which weakens the bonding performance and strength of RBCS,and the SS content should not exceed 45%;As the interface angle increases,the strength of RBCS decreases,and the critical interface slip angle decreases first and then increases with the increase in the E S/E R ratio.This study provides technical references for the large-scale application of SS in mine backfill. 展开更多
关键词 steel slag-cemented paste backfill interface angle rock-backfill composite structures failure mode
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Optimal variable structure control with sliding modes for unstable processes 被引量:4
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作者 KUMAR Satyendra AJMERI Moina 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第10期3147-3158,共12页
In this work,a variable structure control(VSC)technique is proposed to achieve satisfactory robustness for unstable processes.Optimal values of unknown parameters of VSC are obtained using Whale optimization algorithm... In this work,a variable structure control(VSC)technique is proposed to achieve satisfactory robustness for unstable processes.Optimal values of unknown parameters of VSC are obtained using Whale optimization algorithm which was recently reported in literature.Stability analysis has been done to verify the suitability of the proposed structure for industrial processes.The proposed control strategy is applied to three different types of unstable processes including non-minimum phase and nonlinear systems.A comparative study ensures that the proposed scheme gives superior performance over the recently reported VSC system.Furthermore,the proposed method gives satisfactory results for a cart inverted pendulum system in the presence of external disturbance and noise. 展开更多
关键词 variable structure control sliding mode control Whale optimization algorithm ROBUSTNESS non-linear system
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External blast flow field evolution and response mechanism of single-layer reticulated dome structure 被引量:5
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作者 Shao-bo Qi Guang-yan Huang +1 位作者 Xu-dong Zhi Feng Fan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期241-253,共13页
Single-layer reticulated dome structure are commonly high-profile building in the public and can be attractive targets for terrorist bombings,so the public can benefit from enhanced safety with a stronger understandin... Single-layer reticulated dome structure are commonly high-profile building in the public and can be attractive targets for terrorist bombings,so the public can benefit from enhanced safety with a stronger understanding of the behavior of single-layer reticulated dome structure under explosion.This paper investigates the fluid-structure interaction process and the dynamic response performance of the singlelayer reticulated dome under external blast load.Both experimental and numerical results shown that structural deformation is remarkably delayed compared with the velocity of blast wave,which advises the dynamic response of large-span reticulated dome structure has a negligible effect on the blast wave propagation under explosion.Four failure modes are identified by comparing the plastic development of each ring and the residual spatial geometric of the structure,i.e.,minor vibration,local depression,severe damage,and overall collapse.The plastic deformation energy and the displacement potential energy of the structure are the main consumers of the blast energy.In addition,the stress performance of the vertex member and the deep plastic ratio of the whole structure can serve as qualitative indicators to distinguish different failure modes. 展开更多
关键词 External blast loading Reticulated dome structure Fluid-structure interaction Dynamic response mode Response mechanism
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Dynamic behavior of reinforced concrete frame structure during construction 被引量:3
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作者 田明革 易伟建 《Journal of Central South University of Technology》 EI 2008年第3期418-422,共5页
The effects of concrete's time-variant elastic modulus,casting structural components,assembling temporary shoring framework system,and shock by operating construction equipment on dynamic behavior of the reinforce... The effects of concrete's time-variant elastic modulus,casting structural components,assembling temporary shoring framework system,and shock by operating construction equipment on dynamic behavior of the reinforced concrete frame structure during construction were investigated. The dynamic tests of an eight-storey reinforced concrete frame structure during full-scaled stages of the sixth storey construction cycle were carried out by ambient vibration. Natural frequencies,corresponding mode shapes and damping ratio were determined by power spectrum processing the tested signal data in frequency domain. The changes of frequencies,mode shapes and damping ratios at different construction stages were given. The results show that natural frequencies and modal damping ratios reach the maximum at stage of casting fresh concrete,especially for higher modes. Modal damping ratios at each construction stage are less than 5% of those during usage. 展开更多
关键词 structural dynamics ambient vibration structure during construction mode shape natural frequency modal damping ratio
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Experimental study on anti-penetration mechanism of bolted composite protective structure with limited span under impact of low-velocity projectile 被引量:3
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作者 Yu-jia Liu Dian Li +2 位作者 Hai-liang Hou Zhu-jie Zhao Yue Xie 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第6期995-1005,共11页
In order to study the influence of the bolt joint mode on low-velocity projectiles penetrating the composite protective structure,two bolt joint models which connect the composite target to the fixed frame were design... In order to study the influence of the bolt joint mode on low-velocity projectiles penetrating the composite protective structure,two bolt joint models which connect the composite target to the fixed frame were designed,the ballistic test of the bolted composite protective structure with limited span was carried out,and the bearing and failure characteristics of the bolted region,as well as the energy dissipation of each part of the structure,were analyzed.The results show that in the condition of lowvelocity impact,there are three failure modes for the bolted composite protective structure subjected to projectile penetration,including failure of the impact point of the composite target,failure of protective structure connecting components and failure of the holes in the bolted region of the composite target;the failure mode of bolt holes in the bolted region has a great influence on the protection performance,and the allowable value of the bearing capacity of the bolted region depends on the sum of the minimum failure load in the failure modes and the friction force;shear-out failure occurring in the bolt holes in the bolted region exerts the greatest effect on ballistic performance,which should be avoided;When simultaneous failure occurs in the bolted region and the free deformation region of the composite protective structure,the energy absorption per unit surface density of the composite protective structure reaches the maximum,which can give full play to its anti-penetration efficiency. 展开更多
关键词 Impact dynamics Composite protective structure Bolt joint Ballistic test Failure modes
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Decentralized Variable Structure Control of Complex Giant Singular Uncertainty Systems 被引量:1
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作者 Wen Xiangcai&Liu Yongqing (Department of Automation, South China University of Technology Guangzhou, 510641, P. R. China.) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1996年第1期23-34,共12页
This paper, at the first time, considers the problem of decentralized variable structure control of complex giant singular uncertainty systems by using the property of diagonally dominant matrix and Frobenius-Person t... This paper, at the first time, considers the problem of decentralized variable structure control of complex giant singular uncertainty systems by using the property of diagonally dominant matrix and Frobenius-Person theorem. The splendid selection of switching manifold for each subsystem makes the design relatively straightforward and can be easily realized. An illustrate example is given. 展开更多
关键词 Complex giant singular uncertainty systems Multiple input interconnected Decentralized variable structure control Sliding mode Completely controllable.
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Assessment of the ballistic response of honeycomb sandwich structures subjected to offset and normal impact 被引量:1
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作者 Nikhil Khaire Gaurav Tiwari +1 位作者 Vivek Patel M.A.Iqbal 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第10期56-73,共18页
In the present study,experimental and numerical investigations were carried out to examine the behavior of sandwich panels with honeycomb cores.The high velocity impact tests were carried out using a compressed air gu... In the present study,experimental and numerical investigations were carried out to examine the behavior of sandwich panels with honeycomb cores.The high velocity impact tests were carried out using a compressed air gun.A sharp conical nosed projectile was impacted normally and with some offset distance(20 mm and 40 mm).The deformation,failure mode and energy dissipation characteristics were obtained for both kinds of loading.Moreover,the explicit solver was run in Abaqus to create the finite element model.The numerically obtained test results were compared with the experimental to check the accuracy of the modelling.The numerical result was further employed to obtain strain energy dissipation in each element by externally running user-defined code in Abaqus.Furthermore,the influence of inscribe circle diameter and cell wall and face sheet thickness on the energy dissipation,deformation and failure mode was examined.The result found that ballistic resistance and deformation were higher against offset impact compared to the normal impact loading.Sandwich panel impacted at 40 mm offset distance required 3 m/s and 1.9 m/s more velocity than 0 and 20 mm offset distance.Also,increasing the face sheet and wall thickness had a positive impact on the ballistic resistance in terms of a higher ballistic limit and energy absorption.However,inscribe circle diameter had a negative influence on the ballistic resistance.Also,the geometrical parameters of the sandwich structure had a significant influence on the energy dissipation in the different deformation directions.The energy dissipation in plastic work was highest for circumferential direction,regardless of impact condition followed by tangential,radial and axial directions. 展开更多
关键词 Honeycomb sandwich structure Offset impact Energy dissipation characteristic Deformation and failure mode Geometry effect
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Stabilization Variable Structure Control for Singular Decoupling Motor System
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作者 Zou, Wenxun Liu, Yongqing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第1期65-72,共8页
This paper describes the important application of variable structure control (VSC) theory on induction motor (IM) decoupling control system. A design scheme using singular system variable structure control method for ... This paper describes the important application of variable structure control (VSC) theory on induction motor (IM) decoupling control system. A design scheme using singular system variable structure control method for a decoupling IM system is presented. The scheme is shown to be robust to parametric variations and external disturbances. Simulation results show the stability and effectiveness of the proposed scheme 展开更多
关键词 Singular system Sliding mode Variable structure control Decoupling control Switch- ing function.
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Vacuum deposited film growth,morphology and interfacial electronic structures of 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)
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作者 WEI Jun-hua NIU Dong-mei GAO Yong-li 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第4期1041-1061,共21页
Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,... Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)and the interface electronic structures.The film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule interactions.On atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands mode.The initial molecular layer at dielectric,semiconductor and conductive substrates displays slight different lattice structure.The initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase.C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive materials.This usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the interface.Although it is air stable,C8-BTBT is chemically reactive with some transition metals and compounds.The orientation change from lying down to standing up in the film usually leads to decrease of ionization potential.The article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices. 展开更多
关键词 interface film morphology packing configuration growth mode electronic structure chemical reaction interface dipole
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Influence of structural plane angle and roughness on Brazilian characteristics of composite disc specimens
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作者 SHAN Ren-liang DOU Hao-yu +5 位作者 NIE Ming-yue ZHENG Peng LI Geng-zhao PANG Yuan-yang BAI Yao SUN Peng 《Journal of Central South University》 CSCD 2024年第11期4232-4247,共16页
In this paper,Brazilian test was performed on disk samples of analogue materials with defined structural planes.The surface strain evolution process of the disk samples during loading was analyzed via digital image co... In this paper,Brazilian test was performed on disk samples of analogue materials with defined structural planes.The surface strain evolution process of the disk samples during loading was analyzed via digital image correlation.The damage evolution process was explored from a microscopic perspective by combining discrete element numerical simulation technology.The criterion of the failure mode of the disc specimen in the split state was theoretically deduced.The influence of structural surface roughness and loading inclination angle on the stress state at the center of the specimen was explored.The results showed that the failure modes of the samples could be divided into three typical modes as matrix failure,structural plane failure and combination failure.The rough structural plane improves the failure strength of the specimen by limiting its lateral deformation,and the degree of improvement weakens continuously with the increase of the inclination angle of the structural plane.As the inclination angle of the structural plane increases,the main type of microcracks in the structural plane changes from shear microcracks to tensile microcracks.This study contributes to a better understanding of macro-and meso-failure characteristics of rock masses with structural planes under a splitting state. 展开更多
关键词 analogue material structural plane Brazilian test failure mode particle flow code
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宽垄缩行种植模式下播种方式和密度对盐碱地花生群体结构和产量的影响
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作者 慈敦伟 谢宏峰 +7 位作者 张建成 王冕 信志红 唐朝辉 张佳蕾 王秀贞 任超 杨吉顺 《花生学报》 北大核心 2025年第1期16-22,共7页
花生(Arachis hypogaea L.)是重要的油料作物和经济作物,提高单产成为当前保障花生生产的迫切需求。合理群体结构是提高花生光能利用率、增加产量的有效途径之一。本研究选用高产大花生品种花育60为试验材料,在盐碱地宽垄缩行种植模式... 花生(Arachis hypogaea L.)是重要的油料作物和经济作物,提高单产成为当前保障花生生产的迫切需求。合理群体结构是提高花生光能利用率、增加产量的有效途径之一。本研究选用高产大花生品种花育60为试验材料,在盐碱地宽垄缩行种植模式下设置单粒和双粒2种播种方式,每种播种方式设置3个密度。研究表明相同播种方式下,蛋白质含量、油酸含量与O/L、光合速率、各层次冠层透光率、产量构成因素等均随着穴(株)距的增加而增大;而亚油酸含量随着穴(株)距的增加而降低。不同播种方式中,单粒精播产量随着株距的增加而降低,但株距10.0与12.5 cm处理产量无显著差异,而双粒穴播产量则随着穴距的增大而升高;单粒精播除株距15.0 cm处理产量低于双粒穴播各处理外,株距10.0与12.5 cm处理产量均显著高于双粒穴播各处理;单粒精播的蛋白质、脂肪、油酸含量及O/L值、光合速率、各层次的透光率均高于双粒穴播各处理。综合以上研究结果认为,盐碱地宽垄缩行种植模式下单粒精播12.5 cm株距为最优配置。本研究为进一步挖掘盐碱地花生产量潜力和盐碱地花生生产大面积应用提供了理论依据和技术支撑。 展开更多
关键词 花生 盐碱地 种植模式 产量 群体结构
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径向磁通永磁同步电机电磁振噪综述 被引量:1
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作者 毛彦欣 赵文祥 《中国电机工程学报》 北大核心 2025年第9期3667-3684,I0033,共19页
永磁同步电机(permanent magnet synchronous machine,PMSM)因其优越的电磁性能被广泛应用,电机的振动噪声特性作为评价其综合性能的重要技术指标而备受关注。该文对径向磁通PMSM电磁振噪方面的国内外研究工作进行概述,对电磁力、结构... 永磁同步电机(permanent magnet synchronous machine,PMSM)因其优越的电磁性能被广泛应用,电机的振动噪声特性作为评价其综合性能的重要技术指标而备受关注。该文对径向磁通PMSM电磁振噪方面的国内外研究工作进行概述,对电磁力、结构模态、电磁振噪分析及抑制方面的现有研究进行系统归纳。对于电机电磁振噪的抑制,主要介绍结构优化方法和控制策略改进方法。最后,阐述现有PMSM电磁振噪研究存在的问题以及未来可能的发展方向。 展开更多
关键词 永磁同步电机 振动和噪声 电磁力 结构模态 控制策略
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型钢-钢纤维混凝土局部组合梁受力性能 被引量:2
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作者 伍凯 杨毅恒 +3 位作者 诸睿哲 张雁杰 梁庆庆 王世龙 《哈尔滨工业大学学报》 北大核心 2025年第2期153-163,共11页
为解决型钢混凝土结构的施工困难,充分发挥各部分材料的性能优势,将钢筋笼离散化为随机分布的钢纤维,并将钢纤维混凝土集中应用于受压区,形成型钢-钢纤维混凝土局部组合梁。对18根不同钢纤维体积率(ρ_(sf))、剪跨比(λ)、型钢受压翼缘... 为解决型钢混凝土结构的施工困难,充分发挥各部分材料的性能优势,将钢筋笼离散化为随机分布的钢纤维,并将钢纤维混凝土集中应用于受压区,形成型钢-钢纤维混凝土局部组合梁。对18根不同钢纤维体积率(ρ_(sf))、剪跨比(λ)、型钢受压翼缘上下部混凝土保护层厚度(C_(ss)、C_(sv))和型钢规格(I_(s))的组合梁试件进行四点弯试验。分析试验参数对破坏模式、荷载-挠度曲线以及破坏对称性的影响。结果表明:增大ρ_(sf)对小剪跨比试件(λ为1.5或1.7)的界面黏结性能具有积极改善作用,试件破坏模式由界面破坏转为弯扭破坏;混凝土保护层厚度须随I_(s)同步增大,确保混凝土保护层对型钢提供足够的“握裹效应”,避免或削弱弯扭变形的不利影响。通过高斯分布拟合,得到试件整体性能开始出现严重退化时的挠度退化系数,进而对构件整体性能开始出现严重退化时的挠度进行预测。 展开更多
关键词 组合结构 型钢混凝土 钢纤维混凝土 破坏模式 荷载-挠度曲线 能量耗散
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碳纤维复合材料层合板胶接接头力学性能影响因素分析
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作者 张云鹏 梁福地 +4 位作者 杨康 董鹏飞 刘本刚 乔永莲 冯欢 《材料导报》 北大核心 2025年第S1期711-715,共5页
采用结构胶对不同胶层厚度(0.5 mm、1.0 mm、1.5 mm、2.0 mm)、不同被粘物(织物/织物F1F1,预浸料/织物P1F1)以及不同环境(常温干态、高温湿态、水、航空煤油)条件下的碳纤维增强树脂基复合材料层合板的单搭胶接结构进行拉伸剪切试验,研... 采用结构胶对不同胶层厚度(0.5 mm、1.0 mm、1.5 mm、2.0 mm)、不同被粘物(织物/织物F1F1,预浸料/织物P1F1)以及不同环境(常温干态、高温湿态、水、航空煤油)条件下的碳纤维增强树脂基复合材料层合板的单搭胶接结构进行拉伸剪切试验,研究其力学性能。同时,采用扫描电子显微镜(SEM)对胶接接头断裂表面的微观形貌进行分析,探讨其破坏模式。实验结果表明:随着胶层厚度从0.5 mm增加到1.5 mm时,试样常温干态拉伸剪切强度持续降低,减少了21.53%;胶层厚度增加到2.0 mm时强度有所回升;高温湿态环境条件下的强度逐渐减小,降低了49.25%。在相同胶层厚度、不同环境状态条件下,高温湿态环境下的强度最大,在水中浸泡过的强度最小;在常温干态及相同厚度条件下,P1F1的强度均比F1F1的强度大。通过观察胶接接头断面的电镜扫描结果发现,结构胶接接头的破坏模式主要为被粘物失效、胶层失效及两者的混合失效。 展开更多
关键词 结构胶 胶接接头 拉伸剪切强度 失效模式
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基于滚动摩擦的输送机刮板优化设计与效果分析
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作者 郝建 陈琳 +5 位作者 宋旗 李文昕 王端一 张晓峰 贾顺 马彪 《山东科技大学学报(自然科学版)》 北大核心 2025年第2期12-20,共9页
刮板输送机作为综采工作面的核心装备之一,在煤炭生产中承担了巨大工作量。然而传统刮板因其自重过大导致磨损严重,在运行过程中存在高能耗、高载荷和难维护问题,严重影响工作面煤炭运输效率。为了降低刮板自重和磨损,提出了一种优化刮... 刮板输送机作为综采工作面的核心装备之一,在煤炭生产中承担了巨大工作量。然而传统刮板因其自重过大导致磨损严重,在运行过程中存在高能耗、高载荷和难维护问题,严重影响工作面煤炭运输效率。为了降低刮板自重和磨损,提出了一种优化刮板局部结构的设计方案,旨在降低刮板的自重和刮板运行时的摩擦系数,从而减少传统刮板存在的问题。通过模拟实验和工程应用,验证其有效性。研究结果表明:通过改变刮板与中部槽之间的接触方式,使新型刮板的摩擦力比传统刮板减少约89.92%;使用新型刮板的输送机低载荷状态发生频率提升12.5%,中载荷、高载荷、超载荷状态发生频率均有所下降;每台电动机的年用电量降低约25%,内蒙古双欣煤矿年耗电量降低了约27%。本研究为刮板输送机的设计与改进提供了有益的参考,具有实际工程应用价值。 展开更多
关键词 输送机 刮板 自动排污结构 滚动体 摩擦方式
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金属空心球复合结构的吸声性能
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作者 敖庆波 王建忠 +1 位作者 樊永霞 马军 《功能材料》 北大核心 2025年第3期3121-3125,共5页
以金属空心球为基体,利用胶粘法将空心球堆叠成简单立方和密排六方两种典型结构,通过真空烧结制成空心球复合吸声结构。对具有不同材料厚度、空腔厚度、堆叠方式、空心球的材质及大小等结构参数的复合结构进行吸声性能测试,分析结构参... 以金属空心球为基体,利用胶粘法将空心球堆叠成简单立方和密排六方两种典型结构,通过真空烧结制成空心球复合吸声结构。对具有不同材料厚度、空腔厚度、堆叠方式、空心球的材质及大小等结构参数的复合结构进行吸声性能测试,分析结构参数对吸声性能的影响规律。结果表明,随着样品厚度从5 mm增加到20 mm的过程中,第一吸声峰出现在测试频率区域50~6400 Hz内,并从高频区向中低频方向移动;在样品后侧添加空腔,可以使其吸声-频率曲线向中低频移动,且空腔厚度越大,移动的距离越大;空心球的直径越小,复合结构吸声性能越优异;空心球的制备工艺、大小和堆叠方式一致时,材质对复合结构吸声性能的影响效果很小;以密排六方形式堆叠的空心球复合结构较简单立方结构在全频范围内吸声性能好且性价比高。 展开更多
关键词 金属空心球 吸声性能 复合结构 堆叠方式
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耗能支撑-钢框架-剪力墙多重抗侧力混合结构地震破坏全过程拟动力试验及数值分析
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作者 李亮 牛飞宇 +4 位作者 李昀泽 毛孜 周天华 陈军武 何瑶 《土木工程学报》 北大核心 2025年第8期44-56,共13页
为研究装配屈曲约束支撑的钢框架-剪力墙混合结构的抗震性能及耗能机理,文章对一个10层1/8缩尺混合结构试件进行拟动力试验,得到23个工况下结构的位移、加速度响应、剪力墙裂纹发展过程及破坏模式。通过ABAQUS模拟分析进一步研究耗能支... 为研究装配屈曲约束支撑的钢框架-剪力墙混合结构的抗震性能及耗能机理,文章对一个10层1/8缩尺混合结构试件进行拟动力试验,得到23个工况下结构的位移、加速度响应、剪力墙裂纹发展过程及破坏模式。通过ABAQUS模拟分析进一步研究耗能支撑-框架、钢框架及剪力墙三部分之间的能量分配、耗能支撑的塑性耗能和剪力墙的塑性损伤情况。研究表明:(1)屈曲约束支撑(Buckling Restrained Brace,BRB)耗能占结构总耗能的69.9%,其破坏模式主要表现为BRB端部节点板与钢柱之间的焊缝被拉断和BRB端部过渡段面外压弯失稳;钢框架耗能仅占结构总耗能的3.1%,基本处于弹性状态;剪力墙耗能占结构总耗能的16.7%,内部损伤主要集中在混凝土材料上,钢筋与钢骨基本处于弹性状态;(2)剪力墙裂缝首先出现在2~3层,并逐渐扩散至整个剪力墙,裂缝始终为微裂缝且分布较为均匀;(3)BRB显著改善了钢框架-混凝土剪力墙结构的内力分配、变形特征及破坏模式,剪力墙的整体损伤程度较轻,并未出现局部严重破坏。 展开更多
关键词 屈曲约束支撑 混合结构 拟动力试验 剪力墙 破坏模式
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电动汽车液压ABS滑模变结构模糊PID控制设计
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作者 张杰飞 张昊 《机械设计与制造》 北大核心 2025年第4期237-240,245,共5页
为了进一步提高汽车防抱死制动系统(ABS)控制效率和运行平稳性,设计了一种电动汽车液压ABS滑模变结构模糊PID控制方法。在分析液压ABS系统的组成的基础上,构建ABS滑模变结构控制器。在MATLAB/SIMULINK平台建立了模糊PID的控制系统,分别... 为了进一步提高汽车防抱死制动系统(ABS)控制效率和运行平稳性,设计了一种电动汽车液压ABS滑模变结构模糊PID控制方法。在分析液压ABS系统的组成的基础上,构建ABS滑模变结构控制器。在MATLAB/SIMULINK平台建立了模糊PID的控制系统,分别从不同高低附着系数路面以及不同负载工况两方面开展仿真分析。研究结果表明:当路面属于高附着系数时,模糊PID控制后滑移率达到了一个合适的范围,车辆获得了最大制动强度,极大缩短制动距离。在(60~20)km/h范围内进行制动时,轴间滑模控制能够与前后轴制动力分配高效匹配,制动效果理想。处于高-低附路面工况下时,模糊PID控制模式比常规制动与ABS滑模制动性能更优。模糊PID制动快速达到了稳定制动状态。 展开更多
关键词 ABS控制 模糊PID MATLAB平台 滑模变结构
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张力作用下部分浸液带钢振动特性研究
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作者 王兴东 张祖锋 +3 位作者 吕成 胡朝阳 吴宗武 杨芃 《振动与冲击》 北大核心 2025年第13期148-157,共10页
热镀锌带钢正向薄和宽方向发展,沉没辊和塔顶辊间带钢处于部分浸液,振动特性复杂,需研究其柔性特征与流固耦合效应的振动机理。针对弹性支撑的部分浸没带钢,建立了面外振动的动力学模型,分析了模态频率灵敏度影响因子;搭建试验平台,开... 热镀锌带钢正向薄和宽方向发展,沉没辊和塔顶辊间带钢处于部分浸液,振动特性复杂,需研究其柔性特征与流固耦合效应的振动机理。针对弹性支撑的部分浸没带钢,建立了面外振动的动力学模型,分析了模态频率灵敏度影响因子;搭建试验平台,开展了计及张力的不同浸没深度带钢模态试验,建立并验证了部分浸没带钢的有限元模型有效性。依据部分浸没带钢仿真模型,对比分析了其振型特性,定量分析了不同厚度、液体、张力及浸没深度对带钢模态灵敏度的影响。结果表明:随张力和浸没深度增大,各阶模态频率值及宽度方向振型节线分别增大和减小,灵敏度变化与之相反,振型节线更趋向于浸没部分;液体A中频率为液体B中的2.47倍~2.53倍;n=3阶模态灵敏度较大,浸没更深带钢的(0,3)阶模态频率对张力变化的灵敏度更低。 展开更多
关键词 柔性带钢 流固耦合 振型畸变 试验研究 模态灵敏度
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多类城市职住及通勤状态对出行方式选择影响比较
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作者 周雨阳 赵聪颖 +3 位作者 李京昆 陈艳艳 柳堤 王书灵 《交通运输系统工程与信息》 北大核心 2025年第2期26-35,共10页
建立绿色高效的出行服务体系是我国绿色出行行动计划的重要内容,需要考虑居民职住状态和通勤方式在不同等级城市中的异质性。本文基于来自3类城市的1788份有效问卷,构建SEM-MNL(Structural Equation Modeling-Multinomial Logit)模型,... 建立绿色高效的出行服务体系是我国绿色出行行动计划的重要内容,需要考虑居民职住状态和通勤方式在不同等级城市中的异质性。本文基于来自3类城市的1788份有效问卷,构建SEM-MNL(Structural Equation Modeling-Multinomial Logit)模型,量化分析职住状态、通勤属性和个人经济特征对多类别城市通勤方式选择的综合影响。研究发现,潜变量通勤属性是影响出行方式的关键因素,相较于一线和新一线城市,其在普通城市中的约束作用更为明显。职住状态通过通勤属性间接影响通勤方式选择,3类城市路径系数分别为0.83,0.89和0.93。居住类型在一线城市和普通城市对通勤距离和方式选择的作用呈现相反趋势,一线城市高学历者倾向绿色出行,非一线反之。新一线城市短通勤距离居民租房比例最高,且有近半数选择慢行交通。通过调整职住分布提高短距离通勤比例,可以提升绿色出行分担率,随着城市等级下沉,调控反馈灵敏度增高。研究结果为多类城市职住平衡和交通基础设施规划提供了差异化政策建议,有利于促进低碳出行,助推城市交通供需平衡和可持续发展。 展开更多
关键词 城市交通 出行方式选择 结构方程模型 通勤属性 职住状态
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