海洋平台焊接接头低温疲劳裂纹扩展速率研究

针对海洋平台在交变载荷作用下的低温疲劳问题，对焊接接头处的低温疲劳裂纹扩展速率（da／dN）进行了研究。试样所用材料为海洋平台用钢ASTMA131，试样焊接接头的焊接工艺与实际管节点焊接工艺相同。试样接头部位承受弯曲循环载荷，试验环境温度分别为－25℃和20℃。通过对试验数据的处理，得出了低温和室温下的两条da／dN－ΔK曲线。结果表明，两曲线有一交点ΔKp，当应力强度因子幅值ΔK＜ΔKp时，低温环境下试样的da／dN低于室温，结构物偏于安全；当ΔK＞ΔKp时，低温环境下试样的da／dN大于室温，结构物偏于危险。     

带悬伸段柱的计算长度系数的分析和对比

运用小变形弹性稳定理论,通过分析下端刚接的带悬伸段柱的计算模型,导出相应的稳定方程,并将求得的计算长度系数的数值解与下端铰接时的计算长度系数进行对比分析。通过对相应临界荷载的对比分析,指出在确定计算长度系数时常犯的错误。同时给出下端刚接的带悬伸段柱的计算长度系数的设计表格和简化公式。     

复合玻纤风管在我国的应用

本文概述了复合玻纤风管的生产过程，并对该种风管的主要技术特点进行了论述，分析了复合玻纤风管的优缺点．     

网状阳极系统技术标准讨论

提供了网状阳极材料选用参数、设计依据、安装步骤以及调试、验收要求。制定的阳极网接地电阻计算公式,为电源设备选型提供了依据。指出了设计阳极网及电缆选用应遵循的原则,为广大设计人员提供了参考标准。     

油藏综合地球物理技术在垦71井区的应用

油藏综合地球物理技术在油田滚动勘探与开发的储层描述、精细地质建模中发挥蕾越来越重要的作用。油藏地球物理中相关技术的研究在国内外已有不同程度的开展。但针对处于开发中后期老油田剩余油预测的油藏综合地球物理技术的应用研究还很少。为此，开展了包括地质、地震、测井、岩石物理、油藏建模、油气歼发等多学科油藏综合地球物理技术的应用研究。在高精度三维地震、数字三分量检波器采集的二维多波地震、井间地震、三维VSP等资料高分辨率成像的基础上．发展了两项综合应用技术．即提供储层三维空间精细地球物理属性模型的多资料井震联合储层反演技术，以高精度构造解释与储层解释为基础的多尺度资料匹配确定性油藏建模技术。在胜利油田垦71井区应用油藏综合地球物理技术预测剩余油．取得了很好的效果。根据预测结果实施了5口补孔改层措施井，部署了13口新井．钻探结果与预测结果基本相符．预计可提高5％的油气采收率。     

大跨度体育馆空间钢管结构的设计与分析

保定长城体育馆看台为钢框架结构,屋面采用正放三角形钢管桁架结构,弦杆和腹杆均为无缝钢管。采用ANSYS软件,对结构在各主要荷载组合工况下的结构受力进行了分析,结果表明,结构受力合理,构件强度满足要求。分析了结构的整体稳定性和动力特性,计算结果表明,恒载和最不利活荷载组合为结构的最不利工况,结构在此工况下的强度和整体稳定性均满足要求。     

过盈联结过盈量的计算与修正

为保证过盈联结的工作可靠性 ,确定过盈联结的过盈量除了考虑所传递的载荷以外 ,还应考虑其他条件因素对过盈的影响 ,以合理计算联结过盈 ,在满足联结件材料强度的前提下 ,提高过盈联结的可靠性     

10kV SF6环网柜(欧式)与电缆连接存在问题分析及应对措施

从设备、电缆附件、安装工艺等方面分析了10kVSF。共箱式环网柜与10kV电缆连接存在的问题，提出改善的措施。     

The static and fatigue strength of bolted joints in composites with hygrothermal cycling

The effects of hygrothermal cycling upon the performance of a bolted composite joint was examined. Bolt torque relaxed as the number of environmental cycles increased. Comparison with analytical results suggested that the bolt torque “zigzag” behavior probably results from the natural sensitivity of bolted composite joints to the existing ambient temperature and moisture. The washer effect and specimen surface finishes were investigated to study the friction effect on joint bearing performance. Fatigue tests of specimens exposed to hygrothermal cycling exhibited greater hole elongation than specimens not exposed. High preload does improve static failure strength and the fatigue life of specimens under room conditions. Tests run on IM6/3501-6 material specimens with hygrothermal cycling show reasonable declines in fatigue life. The moisture weight gains of composites under hygrothermal cycling exposure were measured and compared to numerical results; good correlation was obtained. As a result, bolt failure occurred in some fatigue tests and is most frequently associated with large thickness-to-diameter ratio. The peak-to-peak stress was defined to study the effect of the R-ratio on bolts for the bolt failure problem.     

Failure of a Fusion Welded Ball Joint as a Result of Modification in MnS Direction

A failure investigation was performed on a ball joint from an ATV front suspension system. The location of the fracture was the bearing ball/stud interface, which is a fusion-welded joint, and occurred after approximately 20 h of field-testing. The two parts are made out of carbon steel and were previously heat-treated. Many elongated MnS inclusions were found in the stud material, and these inclusions were parallel to the symmetry axis. Even though these inclusions were not significantly sized, their number was important. Macroscopic evidence showed that the joint failed in a ductile mode under centered tensile overload. Microscopic examination showed that MnS orientation changed in the fusion joint area. The inclusions had been redirected during the welding process and laid parallel to the fracture surface. This reorientation caused a significant decrease in the effective cross section of the joint and overload fracture occurred.