六自由度盾构管片拼装机机构设计

介绍了一种在盾构隧道施工中,用来给开挖好的隧道表面安装管片的管片拼装机,这是一种六自由度混联机构,整体机构串联中间包含一个二自由度五杆机构.分析了该拼装机的机构组成,工作原理及过程,进行了正运动学和逆运动学的分析,通过具体数值,验证运动学方程的准确性.最后,描述了拼装机对管片轨迹精确调整的过程.     

管片拼装机回转系统齿轮啮合动力学分析

为了研究管片拼装机回转系统齿轮啮合的动力学特性,以管片拼装机小齿轮-大齿圈的传动系统为研究对象,采用集中参数法建立了考虑齿面摩擦的六自由度直齿轮动力学模型,依据管片拼装机实际工况参数,利用Runge-Kutta方法分析了管片拼装机回转系统在空载和负载两种工况下小齿轮和大齿圈的振动位移情况,对管片拼装机回转系统进行了振动测试,验证了模型及求解的正确性,并提出了可以通过增大管片拼装机回转系统刚度来减小振动的方法。研究结果对管片拼装机回转系统的减振和降噪处理,以及提高管片拼装机回转系统的精度有重要的理论和实用价值。     

一种新型盾构管片拼装系统设计与研究

设计了一种六自由度的管片拼装系统实验平台,具有实现平动、仰俯、侧翻、横摇、提升及回转等六个动作的能力,能真实模拟盾构管片拼装系统的实际工况,并从机械结构、液压系统等方面进行了分析与计算。     

3-RPS并联构型的管片拼装新机构

针对现有盾构管片拼装机存在的不足,进行管片拼装机的功能分析,提出基于3-RPS并联构型的管片拼装机构设计新方案。对新机构进行了可行性、运动学和动力学性能分析,表明所提管片拼装机构能很好实现管片拼装过程中的升降、俯仰、摇摆三个动作,提高管片拼装质量。     

管片拼装机提升系统动力学分析与试验

在考虑液压弹簧力和液压摩擦力的基础上建立了管片拼装机提升系统的动力学模型,对管片拼装机提升系统的振动特性进行仿真,分析了管片拼装机在拼装不同位置管片时扼架的振动特性,并进行试验测试,提出了拼装机提升系统的抑振方法.结果表明:在拼装不同位置的管片时,拼装机扼架存在等幅周期性振动,振动速度范围为8～35 mm/s,振动位移...     

浅析管片机旋转运动液压系统

介绍了管片机的六个自由度及其工作原理,分析了管片机旋转运动液压原理,并对旋转马达、管片机泵及多路阀进行选型分析。     

盾构管片拼装机结构及功能简介

管片拼装机是在开挖的隧道上安装混凝土管片的专用装置,管片拼装的质量直接影响盾构施工进程及工程质量。简要介绍了开发的盾构管片拼装机的设备组成、工作原理、主要性能参数及管片拼装的质量要求。     

Φ6.28m盾构管片拼装的机扼架的力学特性

在研发某型号盾构管片拼装机的过程中,为了避免管片拼装机关键部件在运动过程中受力过大断裂造成重大工程事故,应用多体动力学仿真软件,建立整个管片拼装机的动力学仿真模型,对管片拼装机不同安装位置的管片拼装过程进行动力学研究。仿真得到了整个动作过程中关键部件举重钳-扼架在不同工况下的动态载荷与响应特性,并以得到的扼架铰接处的最大动载为边界条件,建立静力学模型。利用Ansys-Workbench对扼架最大受力情况进行有限元分析,分析得到了最大应力为123.24 MPa,确保了管片拼装机扼架部分的强度,仿真分析结果最后通过现场测试得到了验证。     

基于数字样机的TBM管片拼装机运动学和动力学仿真

针对全断面掘进机管片拼装机在设计过程中的约束变量多、干涉情况复杂和设计周期长等问题,进行管片拼装机运动学和动力学仿真的研究.首先对管片拼装机进行了运动学分析,然后利用Pro/E进行三维设计,最后将三维模型导入ADAMS中进行动态仿真.通过对该机构的仿真分析,得出各主动件的速度和驱动力曲线;以空间搜索的方法,找出各主动件的最大速度和最大驱动力,从而获得了管片拼装机的运动学和动力学特性,为机构设计及动力系统的选型设计提供了依据,缩短了设计周期.     

盾构管片拼装机结构强度分析

管片拼装机是盾构机的重要组成部分,主要功能是在掘进开挖完成以后将提前预制好的混凝土管片拼装成环形衬砌,以此来支撑和保护刚刚开挖完成的隧道表面,同时起到防止土体坍塌、渗入地下水及地表坍塌的作用。管片拼装机的转动装置、平移装置、提升装置、微调装置的强度对保证整个拼装机的结构安全和功能完整性起着至关重要的作用。在已确定管片拼装机最不利工作位置的前提条件下,利用通用有限元软件Abaqus作为分析手段,对管片拼装机在管片抓取、管片转动、管片安装三种工况下最不利位置时的结构强度进行校核,以保证管片拼装机结构满足强度和刚度要求。     

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.