基于D-H参数法的四轴机床UG后处理研究

四轴数控机床要发挥其加工优势,离不开与之配套的四轴后处理软件;用NX生成的刀位数据经过后处理解析,才能生成G代码。研究的主要内容包括：运用D-H参数法设计“带A转台四轴机床”的后处理算法;研究基于UG POST Builder专用“A转轴四轴机床”的后处理程序,并用VERICUT进行仿真验证。     

一种鱼雷俯仰角出现±900°时的姿态仿真方法

摘要：随着鱼雷发射平台的多样化,火箭助飞鱼雷、空投鱼雷、自导水雷以及高空反潜鱼雷在发射和运动过程中会出现俯仰角在±900°附近的情况。当鱼雷俯仰角为±900°时,立式三轴转台的内环轴与外环轴重合,无法提供3个自由度的运动,致使鱼雷姿态仿真无法进行。通过改变敏感元件安装方式,建立在该种安装方式下三轴转台的驱动方程以及转台转角与鱼雷姿态角的转换表达式,解决了鱼雷俯仰角出现±±900°时的姿态仿真。数学仿真和半实物仿真结果表明,该方法正确可行,适用于鱼雷垂直发射、垂直入水以及俯仰角出现±900°时的半实物仿真试验。     

小曲率拱型支架支护系统理论与试验分析

针对煤层顺槽梯形支架存在的问题,提出一种新型结构的小曲率拱型支架。采用曲梁模型进行了支架系统的受力分析,得到其最大承载能力;通过与直梁支架承载能力相比较,得到了小曲率拱型支架承载能力系数与曲梁跨度和半径的影响关系。同时进行了地面试压和井下支护工程实验。结果证明:小曲率拱型支架力学性能远优于梯形支架,支撑能力大,自身稳定性良好,有效解决了近距离和下分层煤层巷道不可锚且在强压下难支护的问题。     

The HLD Study of Surfactant Partitioning for Oilfield Corrosion Inhibitors

The partitioning of corrosion inhibitor (CI) products is a measure of their potential to protect oilfield pipelines. In this paper the hydrophilic–lipophilic deviation (HLD) model is first used to quantify their partitioning in terms of the characteristic curvature (C _c,act) of a series of anionic (alkoxylated phosphate esters) and cationic (alkoxylated amines, aromatic amines, imidazoline acetates and quaternary amines) actives. This parameter is expressed over a range of pHs within which pipeline corrosion occurs. The HLD model is next used to predict the partitioning of each active from water into toluene at increased salinities. Linear mixing rules are lastly used to predict the characteristic curvature of Product A (C _c,mix) as a function of the C _c,act of a subset of actives.     

PCO低渗透砂岩油藏裂缝特征综合描述

阿根廷PCO油田VOA1油藏为中孔、超低渗的砂泥岩薄互层砂岩储集层,油藏圈闭是单一大型鼻状构造。通过综合分析岩心资料、构造演化、地震曲率属性、蚂蚁追踪属性及油藏圈闭高部位纯油区内部部分井初产高含水的异常响应数据等资料,对构造裂缝的岩心直观特征、构造应变、空间分布范围和几何特征、动态开启机理等进行了综合描述。研究表明,综合地质、地震、生产等资料从多个角度描述裂缝特征及其相关性,可靠性高,可以大大降低单一方法描述裂缝的不确定性,为生产方案调整提供了有效保障。     

耐低温橡胶的研究进展:分子结构设计与化学改性

综述了耐低温橡胶材料的研究进展,对比了天然橡胶、通用合成橡胶和特种合成橡胶的分子结构、耐低温性能及其影响因素,归纳了耐低温橡胶的改性方法,最后对耐低温橡胶材料今后的发展方向进行了展望。     

基于马达-垫圈的几何形状坐标新算法研究

为提高SCARA机器人机械臂末端执行器的操纵精度,提出一种基于马达-垫圈的几何形状坐标新算法。通过对某款运用仿生设计理论的SCARA机械臂的马达-垫圈装配设备开展视觉处理及精度控制技术研究,对末端执行器采集的马达和垫圈图像进行了图像处理,并基于模板特征进行了垫圈圆心和马达圆心的识别与定位,根据马达模具的几何形状提出一种基于拍3次图像的马达坐标计算方法;进行末端执行器定位精度控制试验,并验证该算法的可行性。结果表明:试验结果远远小于马达装配精度所要求的0.2 mm,证明了该算法能够有效地提高末端执行器的定位精度。     

纯滚动单圆弧齿轮的齿面相对主曲率半径和齿面接触应力分析

根据微分几何原理对纯滚动单圆弧齿轮进行曲率MATLAB仿真,分析了纯滚动单圆弧齿轮的不同参数对相对主曲率半径的影响;基于弹性接触变形理论,计算纯滚动单圆弧齿轮传动的齿面接触应力,考查主要参数对纯滚动单圆弧齿轮齿面接触应力的影响,为后续的纯滚动圆弧齿轮的设计制造具有重要意义,为开发新型的齿轮接触强度计算提供借鉴。     

Effect of prestressed ultrasonic peen forming parameters on bending curvature and spherical deformation of plate

The elastic prestressed ultrasonic peen forming (UPF) was adopted in order to solve problems of insufficient bending deformation and large spherical deformation of plate during free UPF. The theoretical analysis of prestressed UPF and the influence of elastic prebending moment on deformation were analyzed. Spherical deformation coefficient was defined to quantificationally describe the spherical deformation. Experiments were conducted to compare the differences between free UPF and prestressed UPF processes and the effects of processing parameters on bending curvature and spherical deformation coefficient were studied. The results show that peening trajectory in chordwise direction is beneficial to enlarging spanwise bending deformation and decreasing spherical deformation coefficient. Large prebending curvature is helpful to increase spanwise bending deformation and decrease chordwise deformation, thereby obviously decreasing spherical deformation coefficient. Large spanwise deformation can be obtained under large firing pin velocity, small plate thickness and small offset distance. Large firing pin velocity plays a positive role in decreasing spherical deformation, while plate thickness and offset distance have little effect on it. Above all, prebending curvature and peening trajectory are the most important factors during prestressed UPF process. This study provides guidance for parameters optimization of prestressed UPF for wing plate with large thickness.