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雨天路滑现象的力学建模与分析
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作者 丁洲祥 《力学与实践》 北大核心 2017年第4期333-335,348,共4页
针对雨天路滑这一自然现象,基于土力学固结理论、强度理论和有效应力原理等,探讨提出了简化一维等效模型条件下的建模分析方法.采用固结土体抗剪强度除以剪应力的形式,建议了一种道路表面抗滑安全系数.结合工程经验性常见土体参数和路... 针对雨天路滑这一自然现象,基于土力学固结理论、强度理论和有效应力原理等,探讨提出了简化一维等效模型条件下的建模分析方法.采用固结土体抗剪强度除以剪应力的形式,建议了一种道路表面抗滑安全系数.结合工程经验性常见土体参数和路面行走算例,按简化模型进行了定性和定量分析,探讨了路滑的影响因素及其规律.结果表明,在算例条件下,一般砂土路面抗滑安全系数大致为黏土路面的6.0~9.0倍.土力学模型有望为路面抗滑设计和评估提供新的思路. 展开更多
关键词 土力学 路滑 抗剪强度 固结 安全系数
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万家口水电站左岸进场路滑坡的分析及处理
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作者 侯建斌 张会玉 《吉林水利》 2009年第6期42-45,共4页
根据万家口水电站左岸进场路滑坡地形地貌、地层岩性和地下水情况,从滑坡的外貌特征、受力特征角度进行了分析,得出滑坡成因的正确结论,并结合现场的实际情况,提出了较好的处理措施。
关键词 路滑 特征分析 成因结论 处理措施
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船舶主机滑油投油过程控制和周期优化可行性探讨
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作者 丁经龙 《中文科技期刊数据库(引文版)工程技术》 2024年第5期0066-0069,共4页
现代建造船舶,无论是出口海轮还是内河小型船舶,几乎都要靠主机来驱动航行。船舶主机作为船上唯一且重要的动力源,主机的日常安全运转非常重要,对其可靠程度要求是不可言喻的,尤其是为主机服务的滑油日用管路系统更是非常重要,来不得任... 现代建造船舶,无论是出口海轮还是内河小型船舶,几乎都要靠主机来驱动航行。船舶主机作为船上唯一且重要的动力源,主机的日常安全运转非常重要,对其可靠程度要求是不可言喻的,尤其是为主机服务的滑油日用管路系统更是非常重要,来不得任何的马虎。因此一般主机试车前,滑油管路都要进行焊接、投油清洁等工作交由服务商检查确认,清洁交验认可后才能动车。下面我结合个人现场工作经历和领导的指导,浅谈下主机滑油日用管系投油过程中常遇到的问题及改进方法,与大家一起探讨,以便缩短船舶主机投油地周期,为按期或提前交船做好充分的保障。 展开更多
关键词 主机 油管 投油清洁周期
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汽轮发电机组滑油管路高频噪声的消除 被引量:3
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作者 龚存忠 靳军 +2 位作者 张李伟 朱蕾 张承红 《船舶工程》 CSCD 北大核心 2009年第B09期54-55,123,共3页
汽轮发电机组在试验调试期间,滑油管路产生尖叫声,噪声指标大大超出设计要求.通过分析认为滑油管路走向复杂,滑油经节流孔板节流后产生了高频噪声.经过节流孔板结构型式的改造,高频噪声得以消除.利用计算软件对节流孔板进出口附近的滑... 汽轮发电机组在试验调试期间,滑油管路产生尖叫声,噪声指标大大超出设计要求.通过分析认为滑油管路走向复杂,滑油经节流孔板节流后产生了高频噪声.经过节流孔板结构型式的改造,高频噪声得以消除.利用计算软件对节流孔板进出口附近的滑油流场进行理论计算,结果表明改进的节流孔板降低了滑油在管路中的流速,减弱了滑油流动时产生涡的强度,缩短油流稳定时间和距离,使滑油流动在很短距离内稳定,避免出口出现弯头时产生噪声和振动,达到消除噪声尤其是高频噪声的目的. 展开更多
关键词 汽轮发电机组 油管 高频噪声 控制
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你怎么知道路滑
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《健康问答》 2005年第9期48-48,共1页
下雪那天,我匆忙吃完早点,提前出发送儿子去上学。到了学校门口,发现今天来送孩子的家长特别多。儿子一下车就蹦蹦跳跳地往学校里跑,我忙提醒他一句“路滑,注意安全!”这时,旁边一个小孩回头说了句:“知道了,谢谢叔叔!”我儿... 下雪那天,我匆忙吃完早点,提前出发送儿子去上学。到了学校门口,发现今天来送孩子的家长特别多。儿子一下车就蹦蹦跳跳地往学校里跑,我忙提醒他一句“路滑,注意安全!”这时,旁边一个小孩回头说了句:“知道了,谢谢叔叔!”我儿子则没有反应。于是我再喊了一句:“路滑,注意安全!”儿子回过头,奇怪地看了我一眼。仍设有吱声,还是刚才那个小孩答了一句:“知道了!”然后他挽起我儿子的手走了。 展开更多
关键词 儿子 学校 安全 小孩 《你怎么知道路滑 笑话 当代
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IITD算法在滑油管路模态参数辨识中的应用 被引量:3
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作者 边杰 霍常青 +1 位作者 王平 唐广 《郑州大学学报(工学版)》 CAS 北大核心 2018年第1期84-89,共6页
将端点延拓引入本征时间尺度分解(ITD)中用于改进其端点效应,并将改进的ITD法(IITD)用于结构模态参数识别,提出了基于IITD的模态参数识别方法(IITD-MPI).将IITD-MPI用于位移仿真信号和滑油管路测频信号的模态参数识别研究.研究结果表明... 将端点延拓引入本征时间尺度分解(ITD)中用于改进其端点效应,并将改进的ITD法(IITD)用于结构模态参数识别,提出了基于IITD的模态参数识别方法(IITD-MPI).将IITD-MPI用于位移仿真信号和滑油管路测频信号的模态参数识别研究.研究结果表明,对于位移仿真信号而言,与理论值相比,IITD-MPI法辨识的模态固有频率最大误差小于0.6%,阻尼比最大误差为1%.对于滑油管路测频信号而言,IITD-MPI法辨识的模态固有频率与测试模态频率相比,差别在0.15%以内,其辨识的阻尼比与半功率带宽法识别的阻尼比差别不大于3%.由此,验证了IITD-MPI法的有效性和实用性. 展开更多
关键词 本征时间尺度分解 模态参数 参数辨识 仿真与试验 油管
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主机滑油管路优化设计 被引量:3
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作者 程士超 张晓雯 《内燃机与配件》 2017年第15期16-17,共2页
主机滑油管路直接进主机,管路当中的垃圾和污染物会对机器直接造成损伤,所以对管路清洁度要求非常高,目前外高桥现场针对主机滑油管路采取二次拆装清洁后投油的做法,投油周期较长,有的船型出现过投油时间长达半年的情况。本文主要针对... 主机滑油管路直接进主机,管路当中的垃圾和污染物会对机器直接造成损伤,所以对管路清洁度要求非常高,目前外高桥现场针对主机滑油管路采取二次拆装清洁后投油的做法,投油周期较长,有的船型出现过投油时间长达半年的情况。本文主要针对主机滑油管路设计进行优化,从而达到提高现场投油效率,缩短投油周期的目的。 展开更多
关键词 主机投油 油管设计 设备布置
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32500DWT散货船主机滑油管路串油工艺的应用 被引量:2
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作者 梁启龙 《中国水运(下半月)》 2011年第9期100-101,共2页
文中介绍32500DWT散货船主机滑油管路串油工艺的应用。从避免滑油被污染更好地保护主机正常运转角度出发,通过分析滑油管系建造过程存在的各种风险和船舶建造过程各个可能被污染的环节,结合船厂的实际情况采取相应的控制措施。探索如何... 文中介绍32500DWT散货船主机滑油管路串油工艺的应用。从避免滑油被污染更好地保护主机正常运转角度出发,通过分析滑油管系建造过程存在的各种风险和船舶建造过程各个可能被污染的环节,结合船厂的实际情况采取相应的控制措施。探索如何获得最佳的滑油串油方法,最终得出适合本船的滑油管路串油工艺。 展开更多
关键词 油管 串油工艺 船舶主机
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SZH-2型周波继电器中滑差闭锁电路的功能与原理
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作者 李尔京 《中国电力》 CSCD 1993年第4期70-71,共2页
我国电网普遍采用的SZH型数字式频率继电器对电网的安全运行发挥了很大作用,但运行中该型继电器也多次出现误发信号或误动作的现象.为保证该型继电器动作的正确率,提高电网的安全稳定运行水平,对该型继电器又增加了滑差闭锁功能,型号定... 我国电网普遍采用的SZH型数字式频率继电器对电网的安全运行发挥了很大作用,但运行中该型继电器也多次出现误发信号或误动作的现象.为保证该型继电器动作的正确率,提高电网的安全稳定运行水平,对该型继电器又增加了滑差闭锁功能,型号定为SZH-2型周波继电器(简称SZH-2型继电器).本文对滑差闭锁功能的作用、整定原理及工作原理简介如下.1 滑差闭锁功能的作用1.1 防止SZH-2型继电器内部清零回路,计数回路等元件损坏引起的误动作.1.2 防止输入电压相位接连突变(如-相电压变化保险对地闪络、短路故障。 展开更多
关键词 继电器 周波继电器 差闭锁电
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美国国家标准《走路和工作表面防滑材料》(A1264.2)简介
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《化工安全与环境》 2002年第23期15-15,共1页
关键词 美国 国家标准 《走和工作表面防标准》 (A1264.2) 安全
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某船主机机外滑油系统串油清洗工艺设计 被引量:1
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作者 陆洋 酉小广 +1 位作者 左红稳 肖海瑞 《船海工程》 北大核心 2020年第1期107-110,共4页
某在建船舶采用双机双桨的推进型式,针对该双主机机外滑油系统结构较为复杂、难以彻底串油的问题,采用单台主机分阶段串油和2台主机依次串油相结合的方案,设计适用合理的串油工艺流程,高效地完成滑油管路、滑油循环舱、相关设备及附件... 某在建船舶采用双机双桨的推进型式,针对该双主机机外滑油系统结构较为复杂、难以彻底串油的问题,采用单台主机分阶段串油和2台主机依次串油相结合的方案,设计适用合理的串油工艺流程,高效地完成滑油管路、滑油循环舱、相关设备及附件的清洗,使得滑油清洁度达到标准要求。 展开更多
关键词 主机 油管 油循环舱 串油清洗
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浅谈传统串油和化学清洗管路工艺 被引量:3
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作者 胡文凤 徐峰 +1 位作者 叶步永 李移山 《机械工程与自动化》 2021年第3期189-191,共3页
船舶滑油管路在安装完成后要将主机外部的滑油管道、设备及主机内部冲洗干净,以保护主机在使用过程中不被损坏,选择合适的串油工艺方法十分重要。详细介绍了传统串油工艺和化学清洗与串油相结合的具体方法和注意事项,并在时间、成本、... 船舶滑油管路在安装完成后要将主机外部的滑油管道、设备及主机内部冲洗干净,以保护主机在使用过程中不被损坏,选择合适的串油工艺方法十分重要。详细介绍了传统串油工艺和化学清洗与串油相结合的具体方法和注意事项,并在时间、成本、易操作程度和效果4个方面进行对比分析,为船舶建造的串油工艺选择提供参考。 展开更多
关键词 油管 串油工艺 化学清洗 串油
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滑油引起的机损事故
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作者 岳进堂 《中国船检》 2004年第6期98-99,共2页
关键词 船舶 主机 机损事故 事故分析 油管堵塞 维护 保养
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Research on global path planning based on ant colony optimization for AUV 被引量:6
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作者 王宏健 熊伟 《Journal of Marine Science and Application》 2009年第1期58-64,共7页
Path planning is an important issue for autonomous underwater vehicles (AUVs) traversing an unknown environment such as a sea floor, a jungle, or the outer celestial planets. For this paper, global path planning usi... Path planning is an important issue for autonomous underwater vehicles (AUVs) traversing an unknown environment such as a sea floor, a jungle, or the outer celestial planets. For this paper, global path planning using large-scale chart data was studied, and the principles of ant colony optimization (ACO) were applied. This paper introduced the idea of a visibility graph based on the grid workspace model. It also brought a series of pheromone updating rules for the ACO planning algorithm. The operational steps of the ACO algorithm are proposed as a model for a global path planning method for AUV. To mimic the process of smoothing a planned path, a cutting operator and an insertion-point operator were designed. Simulation results demonstrated that the ACO algorithm is suitable for global path planning. The system has many advantages, including that the operating path of the AUV can be quickly optimized, and it is shorter, safer, and smoother. The prototype system successfully demonstrated the feasibility of the concept, proving it can be applied to surveys of unstructured unmanned environments. 展开更多
关键词 autonomous underwater vehicle (AUV) path planning ant colony optimization pathsmoothing
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Mechanical analysis of transmission lines based on linear sliding cable element
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作者 刘云 钱振东 夏开全 《Journal of Southeast University(English Edition)》 EI CAS 2013年第4期436-440,共5页
In order to study the sliding characteristics when the cable structures are connected with other rods, a string of sliding cable dements (SCE) consisting of one active threenode SCE passing through the sliding point... In order to study the sliding characteristics when the cable structures are connected with other rods, a string of sliding cable dements (SCE) consisting of one active threenode SCE passing through the sliding point and multiple inactive two-node SCEs is put forward. Based on the updated Lagrangian formulation, the geometric nonlinear stiffness matrix of the three-node straight sliding cable dement is deduced. The examples about two-span and three-span continuous cable structures are studied to verify the effectiveness of the derived SCE. Comparing the cable tension of SCE with the existing research results, the calculating results show that the error is less than 1%. The sliding characteristics should be considered in practical engineering because of the obvious difference between the cable tension of the SCE and that of the cable element without considering sliding characteristics. 展开更多
关键词 transmission line sliding cable element updated Lagrangian formulation geometric nonlinear
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农用运输车雨天行驶的安全技术
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作者 王淑华 包仁忠 《农业机械化与电气化》 2003年第5期27-28,共2页
1雨天路滑的防范 雨天行车的特点之一是路滑难行,即使在黑色、水泥路面,其制动距离也会大大加长,而在泥泞的乡间土路上行驶,其制动距离更长,这给安全行车带来不利影响.此外,在泥泞路还容易侧滑,甚至操作不当而翻倒.
关键词 农用运输车 雨天 行驶安全 路滑 视线不清 制动失灵 障碍物 防范措施
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Effects of asphalt pavement texture on hydroplaning threshold speed 被引量:5
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作者 Mohammad Hosein DEHNAD Ali KHODAII 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第1期256-264,共9页
Hydroplaning speed can be affected by pavement texture depth,thickness of water film,tire pressure and tread depth.In this study,to understand the influence of pavement texture on the hydroplaning speed,a new lab-scal... Hydroplaning speed can be affected by pavement texture depth,thickness of water film,tire pressure and tread depth.In this study,to understand the influence of pavement texture on the hydroplaning speed,a new lab-scale apparatus has been designed and manufactured.The lack of proportion between linear movement of vehicle shaft and the wheel rotation was found to be a good index to determine hydroplaning threshold.A 5%drop in the ratio of wheel-to-axle rotation has been assumed as an index to determine hydroplaning threshold.Based on the measures,a simplified model was developed that is able to predict the hydroplaning speed depending on pavement's texture characteristics.The results indicated that a 77%increase in mean texture depth cause 9%increase in hydroplaning threshold speed. 展开更多
关键词 asphalt pavement HYDROPLANING surface texture hydroplaning test machine
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Mechanical response of transmission lines based on sliding cable element 被引量:4
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作者 刘云 钱振东 夏开全 《Journal of Central South University》 SCIE EI CAS 2014年第8期3370-3377,共8页
In order to study the sliding characteristics when the cable is connected with the other rods in the transmission line structures,a linear sliding cable element based on updated Lagrangian formulation and a sliding ca... In order to study the sliding characteristics when the cable is connected with the other rods in the transmission line structures,a linear sliding cable element based on updated Lagrangian formulation and a sliding catenary element considering the out-of-plane stiffness coefficient are put forward.A two-span and a three-span cable structures are taken as examples to verify the sliding cable elements.By comparing the tensions of the two proposed cable elements with the existing research results,the error is less than 1%,which proves the correctness of the proposed elements.The sliding characteristics should be considered in the practical engineering because of the significant difference between the tensions of sliding cable elements and those of cable element without considering sliding.The out-of-plane stiffness coefficient and friction characteristics do not obviously affect the cable tensions. 展开更多
关键词 transmission lines sliding cable element updated Lagrangian formulation geometric nonlinearity mechanical response
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Design of micropiles to increase earth slopes stability 被引量:4
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作者 孙书伟 王家臣 卞晓琳 《Journal of Central South University》 SCIE EI CAS 2013年第5期1361-1367,共7页
A methodology was proposed for the design of micropiles to increase earth slopes stability. An analytic model based on bearn-colurnn equation and an existing P-y curve method was set up and used to find the shear capa... A methodology was proposed for the design of micropiles to increase earth slopes stability. An analytic model based on bearn-colurnn equation and an existing P-y curve method was set up and used to find the shear capacity of the micropile. Then, a step-by-step design procedure for stabilization of earth slope with rnicropiles was introduced, involving six main steps: 1) Choosing a location for the rnicropiles within the existing slope; 2) Selecting micropile cross section; 3) Estimating length of rnicropile; 4) Evaluating shear capacity of mieropiles; 5) Calculating spacing required to provide force to stabilize the slope; 6) Designing the concrete cap beam. The application of the method to an embankment landslide in Qinghai Province was described in detail. In the final design, three rows of rnicropiles were adopted as a group and a total of 126 rnicropiles with 0.23 m in diameter were used. The micropile length ranged between 15 and 18 m, with the spacing 1.5 m at in-row direction. The monitoring data indicate that slope movement has been effectively controlled as a result of the slope stabilization measure, which verifies the reasonability of the design method. 展开更多
关键词 micropiles earth slope stabilization lateral response analysis design method P-y curve
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Path Planning for Lunar Surface Robots Based on Improved Ant Colony Algorithm 被引量:1
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作者 SONG Ting SUN Yuqi +2 位作者 YUAN Jianping YANG Haiyue WU Xiande 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第6期672-683,共12页
In the real-world situation,the lunar missions’scale and terrain are different according to various operational regions or worksheets,which requests a more flexible and efficient algorithm to generate task paths.A mu... In the real-world situation,the lunar missions’scale and terrain are different according to various operational regions or worksheets,which requests a more flexible and efficient algorithm to generate task paths.A multi-scale ant colony planning method for the lunar robot is designed to meet the requirements of large scale and complex terrain in lunar space.In the algorithm,the actual lunar surface image is meshed into a gird map,the path planning algorithm is modeled on it,and then the actual path is projected to the original lunar surface and mission.The classical ant colony planning algorithm is rewritten utilizing a multi-scale method to address the diverse task problem.Moreover,the path smoothness is also considered to reduce the magnitude of the steering angle.Finally,several typical conditions to verify the efficiency and feasibility of the proposed algorithm are presented. 展开更多
关键词 ant colony algorithm grid map multi scale path smoothing
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