钻杆螺纹的结构优化与有限元模拟

钻杆螺纹破坏的主要原因是钻杆所受的交变载荷大,产生了较大的应力集中。为缓解内螺纹小端应力集中,在钻杆（如普通钻杆、方钻杆等）上设计和使用了应力减轻槽结构,这些钻杆在使用过程中取得了良好的效果。基于螺纹牙的强度计算公式,用ANSYS软件建立了钻杆螺纹连接有限元分析模型,对有应力减轻槽的钻杆螺纹接触处进行应力分析,并和普通螺纹进行了对比,结果表明加应力减轻槽的钻杆螺纹所受应力大大减小,有益于延长钻杆的使用寿命。     

全液压自动猫道翻板机构动力学仿真分析

根据大陆科学钻探钻机自动猫道的设计要求,设计了猫道的翻板机构。该机构能够代替人工完成在钻井过程中运移钻杆的动作,实现钻具的自动运移。介绍了翻板机构的结构组成、工作原理及机构的动作流程,并利用Inventor软件为设计平台建立翻板机构模型。再利用ADAMS仿真软件,对翻板机构上不同规格的钻杆进行建模分析,测量钻杆的滚落速度以及钻杆与翻板机构之间的接触力。     

深孔加工中浮动环的液力纠偏研究

针对深孔钻削加工过程中钻杆易偏心、切削液对钻杆作用力的研究现状,利用流体力学理论和液体动压润滑原理,分析了深孔加工过程中浮动环对于钻杆纠偏的作用机理。对带有浮动环的BTA深孔加工钻削系统建立数学模型,对油膜厚度的表达式进行推导,并进一步推导了浮动环产生的油膜压力的表达式。利用数值算法对油膜压力进行近似求解,利用Fluent软件对带有浮动环的BTA钻杆系统进行流体仿真分析。研究结果表明:浮动环以一定的转速旋转,形成楔形油膜对钻杆具有纠偏作用。     

基于有限元法的螺旋钻采煤机钻杆结构参数优化

为提高螺旋钻采煤机螺旋钻杆的强度和寿命,减轻钻杆重量,以螺旋钻采煤机的螺旋钻杆为研究对象,在满足强度要求的前提下,以钻杆重量最轻为优化目标,通过Pro/E建立实体优化模型,采用有限元法,在Ansys Workbench软件中进行有限元强度分析,通过观察应力云图,选择螺旋钻杆的壁厚、叶片厚度、高度和螺旋角为变量,对钻杆结构进行参数优化,结果表明,螺旋钻采煤机螺旋钻杆的强度得到了明显提高,应力减小了15.8%,重量减轻了6.4%,延长了钻杆的使用寿命。     

钻杆螺纹的结构优化与有限元模拟

钴杆螺纹破坏的主要原因是钻杆所受的交变载荷大,产生了较大的应力集中.为缓解内螺纹小端应力集中,在钻杆(如钻铤、方钻杆等)上设计和使用了应力减轻槽结构,这些钻杆在使用过程中取得了良好的效果.基于螺纹牙的强度计算公式,用ANSYS软件建立了钻杆螺纹连接有限元分析模型,对有应力减轻槽的钴杆螺纹接触处进行应力分析,并和普通螺纹进行了对比,结果表明,加应力减轻槽的钻杆螺纹所受应力大大减小,有益于延长钻杆的使用寿命.     

深孔加工纠偏钻杆的仿真分析

随着传统深孔加工逐渐向高精度和高难度方向转变,深孔钻削孔轴线偏斜的问题更为突出。在分析已有纠偏技术的基础上提出一种新型的纠偏钻杆结构。通过流体动力学理论,运用FLUENT软件对纠偏钻杆锥形体外壁与深孔内壁之间的切削液流场进行仿真分析,从而验证了本纠偏钻杆结构的可行性。对不同切削液压力情况进行了仿真分析,提出的方法对探索深孔加工孔轴线偏斜纠正具有参考价值。     

BTA深孔钻杆振动主动控制实验研究

为减小BTA深孔钻削加工过程中钻杆振动对刀具寿命和工件加工精度的影响,开发了一种钻杆振动主动控制系统。所设计的超磁致作动器(GMA)能够满足钻削振动高频响和高精度的控制要求。在系统总体设计的基础上分别对钻杆振动模型和作动器动力学特性进行了分析,建立了传递函数模型。利用MATLAB软件对PID算法控制系统进行仿真,最终通过实验验证了所设计的振动主动控制系统对钻杆振动抑制的有效性。     

六自由度钻杆装卸机械手运动学研究

现有工程钻机机器人采用人工装卸方式换接钻杆,其工作效率较为低下且存在安全隐患。为提高钻机的钻杆换接效率,设计了一种六自由度钻杆装卸机械手。在此基础上,利用笛卡尔坐标系建立了机械手的运动学方程,并采用遗传算法运动学方程进行了求解。进一步通过UG软件建立了钻杆装卸机械手虚拟样机模型,并提出了同步驱动和依次驱动两种驱动方案,同时在两种方案下对钻杆装卸机械手的运动学进行了仿真分析,分析结果表明:运动学方程逆解和连杆参数设计正确;机械手同步驱动方式在运动特性方面优于依次驱动方式。研究成果为实现工程钻机人钻杆的自动装卸提供理论基础。     

基于组态技术的石油钻杆生产自动监控系统的设计与应用

随着我国石油工业的高速发展,对石油钻杆的需要不仅表现在数量上的增加,而且对钻杆的质量也提出了更高的要求.运用"kingview"组态软件的强大功能开发监控系统,以实现对钻杆设备运行状况的实时监测、故障报警、数据报表趋势分析与打印、历史数据记录及查询等功能,极大地提高了石油工业自动化水平,有效保证了新钻杆的质量.     

一种多功能小行星采样器的设计

对距离地球较远的小行星表面进行松散土壤和岩石的采样任务时,需要采集不同深度的土壤样品并就地进行分析,并将有价值的数据传回地球。为此研究一种多功能采样器,进行钻进机构、取样机构和密封加热机构等关键组成部分的设计,能实现土壤和岩石样品的采样、体积测量和加热任务。由于钻进过程中,钻杆的约束条件发生变化,为分析钻杆的稳定性,建立动态压杆稳定模型,计算钻杆稳定的临界载荷;考虑钻孔深度变化、钻杆导向约束等不断变化的条件,分析钻杆振动频率的变化规律,利用ANSYS软件仿真,得到了钻杆随钻进深度变化的一阶固有频率区间。对耦合的密封力和加热开关接触力进行计算,得到了满足要求的可靠驱动扭矩。通过原理样机的制作与试验,验证了多功能采样器的设计合理性,达到了质量轻、功耗小、功能多、采样量大的效果。     

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...     

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。     

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...     

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。     

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.     

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.     

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.