燃机端面齿联轴器刚度特性参数化建模与实验

为研究刚度特性对重型燃机端面齿联轴器工作行为的影响,构建端面齿联轴器刚度分析参数化模型,对端面齿接触压力、扭转刚度、压缩变形等重要参数进行计算分析.采用有限元方法研究联轴器结构变形与刚度的变化规律.用实验装置对联轴器的变形和刚度进行了直接测试,刚度模型计算结果与有限元结果以及实验结果吻合较好.研究结果表明:螺栓预紧过程中端面齿及轮盘圆柱发生了不同程度的扭转,导致联轴器各部件刚度特性各有不同,其中端面齿压缩刚度随预紧力增大明显增大,而其它部件的刚度略微减小.由于扭转的存在,端面齿联轴器在变形、刚度变化规律、接触应力及接触状态等特征上有别于一般的联轴器.     

用PHP制作带附件的E-mail

介绍了一种跨平台的简单易学的服务器脚本技术PHP(Personal Home Page)及带附件的电子邮件存放格式,通过实例说明了带附件的电子邮件的实现原理,以及如何使用PHP脚本技术编写基于Web平台的电子邮件的软件包,并给出了相应的实现方法及制作实例.     

基于虚拟样机的液压挖掘机工作装置最大挖掘力分析

针对液压挖掘机工作装置挖掘力的分析计算与优化问题,对工作装置在斗杆挖掘工况下的最大挖掘力及工作装置关键铰接点空间位置对其最大挖掘力的影响进行了研究,提出了采用机械系统与液压系统联合仿真的方法,建立了某液压挖掘机工作装置的虚拟样机模型,分析斗杆油缸以系统最大压力工作,铲斗油缸、动臂油缸闭锁时,在整个挖掘范围内,工作装置的挖掘力图谱,并确定了最大斗杆挖掘力.在此基础上,以最大斗杆挖掘力为设计目标,通过试验设计方法,研究了工作装置机构铰接点空间位置对斗杆挖掘工况下最大挖掘力的影响.研究结果表明,液压挖掘机最大挖掘力达到国外同类产品水平,同时找出了铲斗最大挖掘力位置及数值,为工作装置优化设计和结构强度分析提供了有效依据.     

燃机端面齿微动磨损分析及数值仿真

运用Archard磨损定律以及接触力学理论,研究了燃机端面齿楔形接触面在不同交变载荷力作用下接触面接触压力、接触宽度、间隙量、滑移量等接触特征参数随磨损过程的变化发展规律.结果表明,接触齿面的磨损是由于接触面间反复的相对滑动、磨损导致了接触面几何形貌以及接触压力的改变,这些因素又反过来影响磨损过程.各参数具有时间依赖性...     

Living with and looking at landscape

Landscape is experienced in countless ways by all human beings, both individually and as members of communities, nations and humanity as a whole. Concern for rural locales as the loci of social, economic and domestic existence has, in recent centuries, often been seen in accord, but more usually in conflict, with attachment to the scenic qualities of landscape couched in aesthetic terms. Celebrated in art and in history, landscapes connote stability and security, but living with them is regarded as a virtue, looking at them condemned as shallow scenic appreciation. The stress between these two sets of values is exacerbated by the decline of rural economies throughout the developed world, the abandonment of agricultural landscapes and the loss of traditional countryside ties. Shifting landscape attachments reflect the timing, extent and current pace of rural depopulation. Whether despite or owing to their increasing remoteness from everyday life, landscapes are heavily freighted with moral and symbolic worth as ecological paradigms and as rightful common inheritances, while spurned as scenically frivolous.     

Modeling frequency- and temperature-invariant dissipative behaviors of randomly entangled carbon nanotube networks under cyclic loading

Recent experiments have shown that entangled networks of carbon nanotubes exhibit temperature- and frequency-invariant dissipative behaviors under cyclic loading. We have performed coarse-grained molecular dynamics simulations which show that these intriguing phenomena can be attributed to the unstable attachments/detachments between individual carbon nanotubes induced by van der Waals interactions. We show that this behavior can be described by a triboelastic constitutive model. This study highlights the promise of carbon nanomaterials for energy absorption and dissipation under extreme conditions.      

面向航空液压附件的热处理CAPP系统

主要研究并阐述了面向航空液压附件的热处理CAPP系统.此系统具有友好的界面,使操作人员的每一步操作都在中文提示下进行,并最大限度地减少了需输入的项目.用户在输入基本信息后,系统能自动完成数据查询,实现从热处理工艺设计到工艺卡片自动生成等一系列功能的完整过程.     

手自动一体式直角头设计

结合自动直角头、手动直角头各自特点,在自动直角头结构上增加小角度手动转位功能,使手自动一体式直角头既能在自动直角头的牙盘分度角度加工,也可在特殊角度靠手动微调找准角度后加工,实现360°全方位加工功能。     

Erweiterte Prüfmethoden zur sicheren Rad- und Fahrwerksverschraubung der E-Mobilität

Changes towards electrified vehicles lead to an overall increase of loads in chassis components, particularly in wheel attachments. Especially wheel attachments are facing increased dynamic loads, caused by increased axle loads, wheel dimensions, cornering loads due to tire grip and center of gravity improvements…to name some examples. To prevent fastener failures in future, new measurement and analysis procedures are being presented, enabling a complete and accurate verification of superimposed dynamic stresses caused by dynamic axial and bending loads in wheel & chassis fasteners at its critical failure area. Furthermore load-specific S−N-curves are required to accomplish an appropriate damage accumulation. This detailed understanding of loads occurring at fasteners itselfs enables improved safety in all chassis fasteners, provided these loads are known and taken into account at an early stage of a development process.     

两段预紧的端齿连接转子轴向预紧力的确定

现代涡桨,轴发动机多采用前、后两段分别轴向预紧的端齿连接转子,确定其预紧力的大小是一个极为重要而又非常困难的问题,在已知转子工作时各种载荷引起的轴向松弛力和压紧力的前提下,本文作者曾提出过一个综合考虑紧度裕度,强度裕度、装配关系等多因素的轴向预紧力确定准则。