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.     

深井钻机钻杆自动传送装置载重臂的机械结构设计

以油田普遍使用的深井钻机钻杆自动传送装置为研究对象,对比分析国内外几种成熟的7000 m钻机使用的深井钻机钻杆自动传送装置,设计新型深井钻机钻杆自动传送装置,目的在于提高钻杆等管状钻具的输送效率和安全性。通过实验法,研究钻杆运送过程的受力情况,计算出装置最大受力位置和工作角度,设计深井钻机钻杆自动传送装置的总体结构。采用Solid Edge软件对载重臂等关键部件进行力学仿真计算、校核并制作样机测试系统,对相关数据进行运行操作,进一步优化结构设计,确定最优设计方案。     

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...     

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.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.