薄板零件数控铣削加工变形控制研究

薄板零件数控铣削加工使用通用夹具装夹和传统加工工艺是造成加工后零件变形的主要原因。在分析零件结构特征及加工变形影响因素的基础上,从夹具设计、工艺方法改进、铣削加工工艺改进等方面入手,研究控制薄板零件加工变形的夹持方法、合理的加工工艺等。实践证明提出的改进方法有效控制了薄板零件的加工变形。     

铝合金航空薄壁件数控铣削加工变形预测与分析

在分析铣削加工中材料的变形机理、薄壁件数控铣削加工变形的基本特点的基础上,建立了集成于专业CAD/CAM/FEA系统的薄壁件数控铣削加工变形预测框架,以典型铝合金航空薄壁件数控铣削加工变形进行了预测与试验验证.     

薄壁件铣削技术研究

在航空航天工业中,薄壁件数控铣削是一种常见的典型加工。本文以薄壁件铣削加工过程为研究对象,完成了对薄板支架零件的数控加工工艺分析,建立了薄壁件加工变形的力学模型,应用有限元分析软件,建立了薄壁件铣削加工变形的模拟环境,总结了薄壁件铣削加工变形的规律,提出了薄壁件加工变形补偿的方法,并在Pro/E软件中生成了走刀路线。本研究成果为解决薄壁件铣削加工问题提供了一定的参考和依据。     

支架工艺优化设计及数控铣削加工的研究

采用优化的数控铣削工艺和高速铣削方法进行加工,经检测工件达到合格标准,保证了支架生产经济效益和加工质量。为今后薄壁件加工提供了重要的参考作用。     

纯镍风标加工的变形控制

纯镍风标是一种超薄零件,在加工中易变形.本文从毛坯的加工、数控铣削加工内腔和反面轮廓、零件边缘轮廓加工的过程中寻找控制零件变形的工艺方法.在毛坯加工中,合理运用刨削加工控制毛坯的变形,合理选择数控铣削加工中的刀路,保证了零件的基本轮廓;在加工零件边缘轮廓时使用线切割,在很大程度上减小了风标零件的变形.     

数控铣削加工工艺参数优化方法分析

介绍数控铣削加工工艺和数控铣削加工工艺参数优化方法,通过切削深度及其参数优化、高速铣削加工及其切削参数的确定、五轴铣削加工工艺优化,有效保证数控铣削加工的可靠性与合理性。因此,分析加工工艺参数优化方法对数控铣削具有重要意义。     

数控铣削加工中过欠切成因及对策

简要阐述了数控铣削加工过程中所出现的过欠切现象,并从系统刚性、刀具、铣削方式方法、进给速度、程序指令、工艺安排等六个方面进行成因分析,同时也提出了解决对策,为数控铣削加工时进行正确的工艺分析、合理的编制加工程序提供了可靠的依据,从而提高数控铣削加工精度以及生产效率。     

薄壁零件数控铣削加工工艺技术探讨

本文主要以薄壁零件数控铣削加工工艺技术为重点进行阐述,首先分析了薄壁零件数控铣削加工出现变形情况的关联因素;其次,从结合工件力学特征,调整工艺流程、整合走刀与加工顺序,排除切削的耦合作用、规范制定切削指数,稳定完成数控铣削加工几个方面深入说明并探讨薄壁零件数控铣削加工工艺技术的有效应用,继而强化薄壁零件数控铣削加工操作...     

一种数控铣削加工快速对刀方式的研究与实践

介绍了数控铣削常规对刀方式,提出一种数控铣削快速对刀方式,能显著降低数控铣削作业中更换工件、更换加工面甚至更换机床所带来的重复对刀工作量,这种快速对刀方式能有效提高数控铣削加工效率。     

航空发动机机匣电解加工工艺

目前航空发动机机匣型面加工,主要采用五坐标数控铣削成形加工方法。而数控铣削加工存在一定的缺陷,如机匣材料多数是高温耐热合金,机械切削成形困难,刀具消耗量大,刀具费用高;数控铣削后,材料表面残余应力大,工件易变形,需增加热处理工序消除变形;数控铣削加工周期长,设备占有量大,     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.