一种估算单桩经济直径的方法

在滩海油田开发过程中,经常需要设立立管桩,在环境荷载的作用下,立管桩顶部会发生位移,较大的位移对立管及栈桥的安全很不利,因此需要合理确定单桩的直径。埕岛油田在确定单桩直径时引入了经济直径的概念,文章对经济直径的原理进行了分析,给出了桩顶位移和桩径经济指数计算公式,并举例进行了计算,得出了桩径与桩顶位移及桩径经济指数的关系曲线, 进而求得经济桩径的取值范围。文章还对该方法的优缺点进行了分析。     

Freelance 2000 DCS在轴流机上的应用

简要介绍了Freelance 2000 DCS的功能特点以及轴流机的控制要求.结合轴流机的控制特点，用Freelance 2000 DCS对原模拟电子系统进行改造，实现并改进了轴流机流量－静叶位置调节、防喘振控制、逻辑控制、状态监测、信息管理等功能。改造后的系统可靠性高、技术先进、信息管理功能强，其设计思想和方法均可供石化企业大型压缩机控制系统的设计和改造借鉴。     

新疆伊犁托海水电站拱坝坝体变形监测分析

根据托海拱坝5号坝段、7号坝段例垂线实测资料分析，说明了新疆寒冷地区坝体采取聚胺脂喷涂施工措施后对坝体变形的影响，以及右坝肩渗漏对右坝肩岩体的影响，分析结果为托海水电站通过国家电力公司大坝安全监察中心大坝安全首次定检提供了科学依据。     

轴向进给比对薄壁管滚珠旋压影响的有限元分析

通过有限元数值模拟方法得出滚珠旋压中薄壁管在不同凹模旋转速度条件下轴向进给比的变化规律及工件的成形规律,并对模拟结果的等效应变分布做了分析,并与实验结果进行比较,给出薄壁管滚珠旋压时进给比的选取范围.结果表明,进给比对滚珠旋压中薄壁管直径的胀缩和工件的质量有着显著的影响.另外,从计算的模具所受的三向载荷变化情况分析了模具的使用寿命.     

Determining stress intensity factors of composites using crack opening displacement

The main purpose of this paper is to find the mixed-mode stress intensity factors of composite materials using the crack opening displacement (COD). First, a series solution of the composite material with a crack was used to evaluate COD values. Then, the least-squares method was used to calculate mixed-mode stress intensity factors. This algorithm can be applied to any method that generates or measures COD values. The major advantage of this method is that COD values very near the crack tip are not necessary. Both finite element simulations and laboratory experiments were applied to validate this least-squares method with acceptable accuracy if the even terms of the series solution are removed.     

屏蔽电泵运行中存在问题的分析与改进

对屏蔽电泵在非设计流量下工作存在较大的轴向力不平衡，造成前端轴承磨损严重进行了分析。在不降低效率的情况下，在屏蔽电泵的泵头加入平衡盘使轴向力得到平衡，并取得了满意的效果。     

Numerical modelling for scattering of waves in three-dimensional cracked material

In this paper, a mathematical model is proposed for the problem of the scattering of plane waves in a three-dimensional cracked materials. Instead of obtaining closed-form solutions as in conventional theoretical analysis methods, this approach, called the Equivalent Nodal Force (ENF) method formulates the mechanical effects of cracks as an equivalent nodal force in a numerical procedure, and physically translates cracked material into an equivalent continuous one. Several mechanical relations between waves and cracks are evident from this method. Also the results of several numerical calculations are presented and these are compared with those obtained by the conventional methods.     

分割电极片状压电致动器——(二)位移特性及狭缝宽度对其影响的实验研究

研究了悬臂梁式分割电极片状压电致动器的位移特性。理论分析表明，分割电极狭缝宽度会减小致动器自由端的位移输出，但当狭缝宽度小于致动器电极宽度的１０％时，可忽略狭缝宽度的影响。致动器端部位移的测试结果大于理论计算值。与现有磁头悬浮臂尺寸相近的致动器，在２０Ｖ～５０Ｖ的电压驱动下均可获得１μｍ～２μｍ的致动位移。对９８５０道／厘米的密度磁盘，该位移能覆盖至少一个磁道宽度，满足磁头定位两级伺服系统对第二级致动器位移的基本要求。     

Prediction of axial velocity profiles and solids hold-up in a rotary kiln

Axial bed depth profiles were experimentally measured in a rotary kiln containing ilmenite particles under steady state and transient conditions. The variables include feed rate of solids, inclination and rotational speed of the kiln. and dam height. The variation of the axial velocity with kiln axis was estimated. The semi-experimental model proposed by Perron and Bui (1990) was modified to include the effect of the variables of the present study. The mean residence time of solids was estimated from the fractional hold-up and expressed in terms of the process variables. The transients induced by a step change in any of the operating conditions were measured as variation of discharge rate of solids with time.     

光电摆角动态测量原理及其测量系统

本文阐述了用于测量物体摆角及摆心浮动量的光电动态实时测量原理,以及根据此原理研制的光电导弹喷管摆角动态测量系统。