检索结果-南通市图书馆

Science China(Technological Sciences) 2021年第2期64卷 297-316页

作者： ZHANG Rui meng xianghui LYU BuGao SUN Kai School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China AECC Commercial Aircraft Engine Company Limited Shanghai 200241China

Accurate contact calculations of real rough surfaces are fundamental but complicated. The model-based methods are convenient and straightforward. But these methods ignore some factors and may lead to less accurate results. This is especially true when considering multi-scale topographic features of engineering rough surfaces. Based on artificially generated rough surfaces, the deterministic contact analysis of two 3D rough surfaces is conducted by the finite element method(FEM). The calculations show that when the separation between surfaces reduces, results of classic model-based methods are quite different from those of this study, especially when the roughness distribution and textures are considered. As friction pairs are working under increasing harsh conditions, the accurate contact calculation in this paper will be of great significance.

关键词： deterministic contact analysis multi-scale topography finite element method(FEM) engineering rough surfaces

Transient tribo-dynamic analysis of crosshead slipper in lowspeed marine diesel engines during engine startup

在线全文

学校读者我要写书评

暂无评论

Friction 2021年第6期9卷 1504-1527页

作者： Rui LI xianghui meng Jingjin DONG Wenda LI State Key Laboratory of Mechanical System and Vibration Shanghai Jiaotong UniversityShanghai 200240China School of Mechanical Engineering Shanghai Jiaotong UniversityShanghai 200240China China Shipbuilding Power Engineering Institute Company Limited Shanghai 201206China

A crosshead slipper-guide system,which bears a significant thrust force,is an essential friction pair in low-speed marine diesel *** to the low moving speed of the crosshead slipper during engine startup,it is difficult to form good hydrodynamic lubrication between the crosshead slipper and ***,a detailed analysis of the crosshead slipper during engine startup is *** this study,a new transient tribo-dynamic model for a crosshead slipper during the engine startup process is *** model consists of a mixed lubrication model of the crosshead slipper-guide and dynamic models of the piston assembly,crosshead assembly,connecting rod,and *** tribo-dynamic performances of the crosshead slipper during startup and under the rated conditions were simulated and *** results show that the tribo-dynamics of the crosshead slipper during the startup process are significantly different from those under the rated *** measures beneficial for the low friction of a crosshead slipper-guide under the rated conditions may significantly increase the friction loss of the crosshead slipper-guide system during the startup process.

关键词： low-speed marine diesel engine crosshead slipper engine start-up mixed lubrication friction loss tribo-dynamic model

Analysis of the coated and textured ring/liner conjunction based on a thermal mixed lubrication model

在线全文

学校读者我要写书评

暂无评论

Friction 2018年第4期6卷 420-431页

作者： Chunxing GU xianghui meng Di ZHANG State Key Laboratory of Mechanical System and Vibration Shanghai Jiaotong University School of Mechanical Engineering Shanghai Jiaotong University School of Mechanical Electronic Technology Shanghai Jianqiao University

For the ring/liner conjunction, well‐designed surface texturing has been regarded as a potential means to improve its tribological performance, as well as the application of coating. However, so far most researchers focused on the one of these aspects. In this study, the combined effect of coating and texturing on the performance of ring/liner conjunction is numerically investigated. A thermal mixed lubrication model is presented. The effects of the coating's thermal and mechanical properties on the tribological performance are studied under the cold and warm engine operating conditions. Along with the increasing coating thickness, the effects of the coating's thermal properties on friction loss are found to be significant, as well as the effects of the coating's mechanical properties. It is also found that a soft coating with a lower thermal inertia has a greater ability to reduce the friction loss of the textured conjunction.

关键词： thermal mixed lubrication surface coating surface texturing piston ring tribological performance

Blow-by and tribological performance of piston ring pack during cold start and warm idle operations

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2016年第7期59卷 1085-1099页

作者： CHENG Jun meng xianghui XIE YouBai KONG XiaoLi School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240 China Research and Development Center of China's First Automotive Works (FAW) Group Changchun 130011 China

To reduce the fuel consumption of internal combustion engines, more attention has been paid to the tribological performance of the piston ring pack during the cold start and idle operations. In this research, a numerical model considering the cylinder liner deformation and the piston ring conformability is developed to predict the blow-by, lubrication, friction and wear of the piston ring pack under different operating conditions. The gas flow rate, inter-ring gas pressures, minimum oil film thickness, frictional force and wear load during cold start are calculated and compared with those during warm idle operating conditions. The results show that cylinder liner deformation and piston ring conformability together obviously affect blow-by and other tribological performance. Meanwhile, it is found that friction loss is larger during cold start than during warm idle operating conditions. However, the wear process is more severe during warm idle operation than during cold start. From this research, the blow-by and tribological performance of the piston ring pack during cold start and warm idle operations are understood more deeply.

关键词： cold start warm idle piston ring pack deformation blow-by

Scuffing failure analysis based on a multiphysics coupling model and experimental verification

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第6期12卷 1214-1234页

作者： Bugao LYU xianghui meng Jiabao YIN Yi CUI Chengen WANG School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

General reductions in lubricant viscosities and increasing loads in machine components highlight the role of tribofilms in providing surface protection against ***,the relationship between the scuffing process and the growth and removal of tribofilm is not well *** this study,a multiphysics coupling model,which includes hydrodynamic lubrication,asperity contact,thermal effect,tribochemistry reaction,friction,and surface wear,was developed to capture the initiation of surface *** and experiments for a piston ring and cylinder liner contact were conducted following a step-load sequence under different temperature *** results show that high temperature and extreme load could induce the lubricant film collapse,which in turn triggers the breakdown of the tribofilm due to the significantly increased removal *** failures of both lubricant film and tribofilm progress instantaneously in a coupling way,which finally leads to severe scuffing.

关键词： scuffing failure tribofilm boundary lubrication multiphysics coupling effects

Starved lubrication analysis of angular contact ball bearing based on a multi-degree-of-freedom tribo-dynamic model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2023年第8期11卷 1395-1418页

作者： Chengwei WEN xianghui meng Jiaming GU Lin XIAO Shuang JIANG Hanbing BI State Key Laboratory of Mechanical System and Vibration Shanghai Jiaotong UniversityShanghai 200240China School of Mechanical Engineering Shanghai Jiaotong UniversityShanghai 200240China Bearing Technical Center Shanghai Prime Machinery Co.Ltd.Shanghai 201108China Shanghai Tian An Bearing Co. Ltd.Shanghai 201108China

When the oil supply is not adequate to maintain the ideal lubrication,angular contact ball bearing will enter into the starved lubrication regime resulting in the potential performance degradation and consequently the severe *** study the effects of starved lubrication on the performance of angular contact ball bearing,this paper first proposes a multi-degree-of-freedom(DOF)tribo-dynamic model by introducing five-DOF inner ring,six-DOF balls,and six-DOF *** model considers the starved lubrication in the ball-raceway contact and the full multi-body interactions between the bearing *** different ball-raceway starvation degrees being analyzed,the effects of starved lubrication on the bearing tribo-dynamic performance are first *** comparison,it is found that the oil film thickness,the skidding performance,and the traction forces in the ball-raceway contact are significantly influenced by the starvation *** is also found that the starvation-induced change of the ball-pocket contact force is dramatical under combined loads,and the maximum contact force under this load condition increases with the increasing starvation degrees.

关键词： angular contact ball bearing starved lubrication tribo-dynamic performance multi-body interactions

船用柴油机十字头滑块摩擦动力学影响因素分析

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

上海交通大学学报 2020年第10期54卷 1035-1044页

作者：李瑞孟祥慧上海交通大学机械与动力工程学院上海200240

针对船用低速柴油机的十字头滑块-导板摩擦副,基于所建立的摩擦动力学模型和数值求解方法,分析滑块-导板配合间隙、润滑面积、滑块型线、曲轴偏置和十字头销偏置对十字头滑块摩擦动力学特性的影响.研究结果表明:增大滑块-导板的间隙可... 详细信息

针对船用低速柴油机的十字头滑块-导板摩擦副,基于所建立的摩擦动力学模型和数值求解方法,分析滑块-导板配合间隙、润滑面积、滑块型线、曲轴偏置和十字头销偏置对十字头滑块摩擦动力学特性的影响.研究结果表明:增大滑块-导板的间隙可以有效减小摩擦损失,但同时也会显著增加滑块的最大敲击能,从而加剧发动机的振动和噪声.曲轴向主推力侧偏置可以降低滑块的摩擦损失和发火上止点后的侧向力,同时最大敲击能也有所降低.十字头销向主推力侧偏置则使滑块的摩擦损失增大,发火上止点后的侧向力也有所上升.

关键词：船用柴油机十字头滑块混合润滑二阶运动摩擦动力学

在线全文

学校读者我要写书评

暂无评论

粘温效应对十字头滑块与活塞裙润滑影响分析

哈尔滨工程大学学报 2019年第12期40卷 1980-1985页

作者：李瑞孟祥慧上海交通大学机械与动力工程学院

为了研究船用低速二冲程柴油机关键摩擦副的摩擦动力学问题,本文依据多体动力学和混合润滑的基本原理,考虑润滑油的粘温效应,分析了工作温度下十字头滑块与活塞裙的摩擦学与动力学特性,并与冷态分析结果做了对比。结果表明:在工作温度下... 详细信息

为了研究船用低速二冲程柴油机关键摩擦副的摩擦动力学问题,本文依据多体动力学和混合润滑的基本原理,考虑润滑油的粘温效应,分析了工作温度下十字头滑块与活塞裙的摩擦学与动力学特性,并与冷态分析结果做了对比。结果表明:在工作温度下,十字头滑块和活塞裙的摩擦损失更小,但二阶运动更剧烈。同时,剧烈的二阶运动使得十字头滑块在发火上止点后,主推力侧的最小膜厚明显降低。

关键词：十字头滑块活塞裙粘温效应混合润滑摩擦学动力学二阶运动数值模拟船用低速柴油机

在线全文

学校读者我要写书评

暂无评论

煤矿钻探用钻杆疲劳寿命预测研究

煤炭科学技术 2020年第6期48卷 148-153页

作者：孟祥辉中煤科工集团重庆研究院有限公司重庆400039 瓦斯灾害监控与应急技术国家重点实验室重庆400039

目前矿用钻杆在煤矿井下施工疲劳寿命预测困难,无报废标准和报废依据,导致煤矿井下钻杆断裂事故频发,严重影响煤矿井下勘探钻孔、瓦斯抽采钻孔、探放水钻孔的施工安全和施工进度。矿用钻杆的工况条件复杂,基于弹塑性力学无法对钻杆疲劳... 详细信息

目前矿用钻杆在煤矿井下施工疲劳寿命预测困难,无报废标准和报废依据,导致煤矿井下钻杆断裂事故频发,严重影响煤矿井下勘探钻孔、瓦斯抽采钻孔、探放水钻孔的施工安全和施工进度。矿用钻杆的工况条件复杂,基于弹塑性力学无法对钻杆疲劳寿命、断裂失效原因、结构工艺的优化提高进行可靠研究;通过综合钻杆所受到转矩、弯矩、轴向力以及井壁的约束作用力等复合载荷条件建立钻杆约束模型,提出基于断裂力学和损伤力学、运用解析法和有限元分析方法对钻杆的疲劳寿命进行研究,并基于研发的钻杆动态性能试验系统对钻杆的疲劳寿命进行试验,提出矿用钻杆疲劳寿命预测研究方法,为钻探施工和钻杆的设计提供依据。结果表明:按照现有钻杆杆体、螺纹的加工工艺,73型钻杆在转矩4000 N·m,施工钻孔终孔直径为96 mm时,通过钻杆动态性能试验系统对钻杆的疲劳寿命进行试验,钻杆的疲劳寿命为5.32×10^5~4.78×10^5转,疲劳寿命与所建立的钻杆疲劳寿命预测模型一致,钻杆疲劳寿命最小位置在公螺纹处,杆体在受到1 mm以下划痕对钻杆整体疲劳寿命无影响。

关键词：钻杆疲劳断裂寿命预测裂纹钻探

在线全文

学校读者我要写书评

暂无评论

基于配置约束处理的产品配置设计方法

西安交通大学学报 2006年第11期40卷 1315-1319页

作者：孟祥慧蒋祖华上海交通大学机械与动力工程学院上海200030

为了解决复杂的配置设计问题,提出了一种集成配置设计方法.该方法包括3个相互协作的过程:通过实例匹配技术从现有设计实例库中搜索满意设计解;通过领域知识的支持解决具有强烈知识依赖性的模块配置问题及关键参数的赋初值问题;通过进化... 详细信息

为了解决复杂的配置设计问题,提出了一种集成配置设计方法.该方法包括3个相互协作的过程:通过实例匹配技术从现有设计实例库中搜索满意设计解;通过领域知识的支持解决具有强烈知识依赖性的模块配置问题及关键参数的赋初值问题;通过进化算法解决配置设计过程中参数的求解和优化问题.针对参数求解和优化过程中的一些复杂配置约束,在传统进化算法的基础上提出了约束校核操作和再设计规则的配置约束处理方法.最后以蜗杆减速器为实例,验证了所提出的基于配置约束处理的产品配置设计方法能够快速给出良好的设计解,从而为复杂产品的配置设计问题提供求解方案.

关键词：配置约束配置设计进化算法领域知识