可调角度弯钻杆的研制

在处理井下事故特别是藏鱼头事故时,由于鱼头不居中,甚至贴在井径变化较大处,因此很难实施普通打捞。现场普遍采用可弯肘节和折弯钻杆的方式进行寻找落鱼,实施打捞,有可能多次折弯钻杆,造成浪费,甚至造成井下更复杂情况的发生。根据这一情况,设计了可调角度弯钻杆。可调角度弯钻杆由上接头、花键体、调整套、下接头等组成,通过调节调整套和花键体等机构,可实现弯钻杆0°-4°调节。已完成可调角度弯钻杆的样机制造,并在多口井中进行应用。结果表明,采用可调角度弯钻杆可有效实施藏鱼头打捞,井口调节方便,应用取得了成功;单井可节约近30万元。     

输气管道弯管轴向作用力的分析

从弯管的受力分析入手，通过积分计算，分析了弯管与相邻直管段的轴向作用力，并了该轴向作用力的计算公式，为弯管的和分析打下了基础。     

Plastic loads of pipe bends under combined pressure and out-of-plane bending

This paper provides plastic limit and TES (twice-elastic-slope) plastic load solutions for 90° pipe bends under combined pressure and out-of-plane bending, via three-dimensional non-linear FE analyses using elastic-perfectly plastic materials. Without internal pressure, a closed-form approximation is given. For combined pressure and out-of-plane bending, tabulated data are given, from which TES plastic loads can be interpolated. It is found that TES plastic loads for pipe bends under out-of-plane bending are lower than those under in-plane opening bending, but are higher than those under in-plane closing bending. It suggests that the in-plane closing bending mode is the most critical loading mode for 90° pipe bends, which is fully consistent to existing findings.     

Fracture behavior of a corroded structural component under bending load

In order to clarify the significance of corrosion damage for risk assessment, bend tests were carried out on a roughened corroded annular plate prepared from an oil storage tank. It was found that a marked decrease of load carrying capacity occurred in the high deflection region depending upon the degree of corrosion damage. The reason for extensive loss of load carrying capacity was successfully explained from successive observation of crack growth behavior on the corroded surface of the annular plate. Photographic evidence showed that multiple cracks, initiated around individual pits, grew rapidly not only by crack growth, but also by coalescence with other neighboring cracks under the influence of plastic constraint derived from the welded joint. The linking up of multiple cracks leading to a catastrophic failure was considered to be a characteristic event of the roughened corroded component, and was expected to occur depending upon the degree of corrosion damage under a complex stress state.     

多层介质中多导体拐角结构电容参数的提取

本文给出一种计算多层介质中多导体拐角互连结构的准静态电容参数的快速算法─—维数缩减技术（DRT），并和有限差分法相结合，快速、准确地提取了多层介质中多导体拐角结构的准静态电容矩阵。由于维数缩减技术能充分利用集成电路结构分层的特点，从而大大减少了计算所需的时间和存储空间。文中给出的计算结果与Ansoft软件的计算结果吻合得较好，而计算所需的时间和存储空间大大少于Ansoft软件。     

复杂环境危房的爆破拆除

介绍了两栋复杂环境危房的爆破拆除，分别为排架结构加框架结构的混合结构和砖混结构的五层楼。根据周围环境和待爆建筑物的结构特点，简要分析了排架结构失稳下坠时的受力状况，排架结构加框架结构的混合结构采取纵向逐排爆破倒塌的方案，较好地控制了倒塌方向和范围。     

Spacesuit: Fashioning Apollo,Nicholas de Monchaux

Abstract

In this article, Cooks examines quilts is echoed in the work of other contemporary artists. She analyzes how references to the how the aesthetic of Gee's Bend quilts lend Black credibility to the art that has the potential to critically comment on the history of race, poverty, and social injustice in America.     

PROTOS M5卷接机组梗签输送装置的优化设计

为解决PROTOS M5卷接机组梗签输送装置中输送管道容易堵塞问题,通过Solid Works建立管道模型,利用Fluent分析软件模拟空气在管道中流动的形态,对流体在管道中的压力和流线进行分析,得到梗签输送管道的堵塞原因并对该装置进行了优化设计:将封闭式弯管改为开放式振槽,缩短输送管道长度;增加切碎梗签功能,将较长梗签切断,避免过长梗签卡在管道弯曲处;采用直管连接梗签箱与集中负压源,减少负压损失。结果表明:1管道在最大弯曲处、同一截面上出现螺旋式流动时,或在最大弯曲处出现流速为零时,以及管道压力损失过大时,均容易造成管道堵塞。2改进后管道压力和流线分布均匀,管道压力损失由452.8 Pa减小到245.5 Pa,有效解决了梗签输送管道堵塞问题。     

模型试验中的阵发性不稳定流态及折冲流——李家峡水电站左底孔试验中的两个问题

本文证实李家峡水电站左底孔不存在阵发性不稳定流态问题,模型上的这种不良流态是模拟条件引起的。文章分析了与折冲流有关的因素,如压差、压力和流速梯度以及渥奇面参数,进而提出了修改方案,基本解决了该孔存在的折冲流问题。     

Particle dynamics analysis in bend in a horizontal-vertical pneumatic conveying system with oscillatory flow

The pneumatic system is frequently operated in the high air velocity region, which aggravates the power consumption and erosion of bend, and the intensive study of the particles motion characteristic on a horizontal-vertical pneumatic conveying in various curved 90° bends is necessary. This experimental study focuses on the particles motion characteristic of bend on the horizontal-vertical pneumatic conveying with oscillatory flow (generated by installing the oscillator) in terms of on pressure drop, powder consumption, the evolution of particle velocity and particle fluctuating intensity during flowing through bends. The results indicate that powder consumption can be reduced by using oscillatory flow, which is more obvious with a larger radius ratios bend. Meanwhile, the pressure drop proportion of bend is higher than average pressure drop of the system within the same distance. Otherwise, the total reduction particles velocity through bend is less while using oscillatory flow, which is more obvious using larger radius ratios bend. The particle velocity using oscillatory flow is higher than that of the conventional pneumatic conveying for the cases of larger radius ratios bend, and this effect is less evident while through a smaller radius bend.