新型D形螺栓U形管式换热器结构改进

提出将现有螺纹锁紧环U形管式换热器管箱端盖上的锁紧环梯形螺纹用一组D形螺栓连接替代,并将原螺纹锁紧环与管箱盖板合为一平顶盖的新型端盖结构,使得该换热器装拆方便、制造简单且重量减轻。此外,还对D形螺栓、筒体端部及平顶盖进行了强度分析,并将其与原结构进行了简单比较。     

钢筋剥肋滚轧直螺纹连接质量监督浅谈

针对内螺纹与外螺纹接触面积过小造成在荷载尚未达到规定值时钢筋从套筒中拔出现象,从3个方面分析接触面积过小原因,提出相应钢筋剥肋滚轧直螺纹连接质量监督措施,消除施工中存在质量与安全隐患,确保钢筋剥肋滚轧直螺纹连接质量。     

Improved design of threaded connections by autofrettage in aluminium compounds for cyclic high pressure loading: design calculations and experimental verification

Threaded connections in an aluminium valve body under high internal pulsating pressure are investigated. A static straining process called autofrettage leads to an improved fatigue behaviour of the aluminium component, while normally the threaded connections are unloaded during this autofrettage. But by unloading the thread during autofrettage, the first loaded thread flank becomes the weakest point of this valve component. This effect is analysed with nonlinear finite element simulations, the FKM guideline for fatigue assessment and by experimental testing. The analytical and experimental parts match very well. It can be shown that a well‐designed autofrettage without unloading the threaded connection is helpful for the aluminium thread and extends its fatigue lifetime, as residual compressive stresses and an equalized stress distribution over the thread flanks can be achieved. Finally, different materials were chosen for the plug or screw, and this material influence for cyclic loading is shortly analysed.     

浸渍对炭-石墨材料孔隙孔径的影响

以进口Ф 288 mm接头为试样，对其进行了二浸三烧及石墨化处理，并逐阶段对不同孔隙孔径的填充情况做了图像分析的微区定量测试，从测试结果中可看出浸渍的效果与炭－石墨材料孔隙孔径的大小有直接关系。     

浅谈钢筋直螺纹连接技术的应用

结合工程实例，对钢筋直螺纹连接技术的应用进行介绍，该技术连接可靠，有较大的综合经济技术效益，值得推广应用，     

异种材料典型螺纹联接件在预紧和热循环条件下的力学行为

在核电厂堆内构件中,如果螺纹联接结构的联接件和基体采用两种不同的材料,由于螺纹联接件材料的热膨胀系数小于基体材料,在升温过程中将产生较大的附加应力.本文以典型螺纹联接件M12为例,模拟堆内热循环载荷条件,对其进行有限元仿真计算分析.在与试验结果及理论分析、经验公式互相比较的基础上,对预紧力矩、螺纹联接件和基体的变形量、联接件在预紧力、升温、降温等不同载荷条件下的应力等参量变化情况进行了研究,为工程设计提供了可靠的依据.     

Phase-field simulation of dendritic solidification using a full threaded tree with adaptive meshing

Simulation of the microstructure evolution during solidifi cation is greatly benefi cial to the control of solidifi cation microstructures. A phase-fi eld method based on the full threaded tree(FTT) for the simulation of casting solidifi cation microstructure was proposed in this paper, and the structure of the full threaded tree and the mesh refi nement method was discussed. During dendritic growth in solidifi cation, the mesh for simulation is adaptively refi ned at the liquid-solid interface, and coarsened in other areas. The numerical results of a threedimension dendrite growth indicate that the phase-fi eld method based on FTT is suitable for microstructure simulation. Most importantly, the FTT method can increase the spatial and temporal resolutions beyond the limits imposed by the available hardware compared with the conventional uniform mesh. At the simulation time of 0.03 s in this study, the computer memory used for computation is no more than 10 MB with the FTT method, while it is about 50 MB with the uniform mesh method. In addition, the proposed FTT method is more effi cient in computation time when compared with the uniform mesh method. It would take about 20 h for the uniform mesh method, while only 2 h for the FTT method for computation when the solidifi cation time is 0.17 s in this study.     

双油管完井工艺技术

双油管完井所需的井下工具较多,工艺也比较复杂,在我国油田开发中是一项比较新的完井工艺技术。本文通过涠10-3油田7口井次的施工实践,介绍有关双油管完井的一般井下管柱结构、完井工具及作用和现场施工工艺等。     

大口径特殊套管接头TP-QR的开发

针对13.375in及以上的大口径API套管接头存在的上扣速度慢、接头应力高、上扣控制难等问题,研制了专用于大口径快速上扣的套管特殊接头TP-QR。该产品通过了ISO 13679 CAL II实物性能试验,其抗粘扣性能、密封完整性、结构完整性达到了产品设计要求,并在油田完成了下井使用。     

带内螺纹的望远镜镜身注塑模具设计

分析了望远镜镜身的结构,提出了塑件成型及模具设计的关键点,设计了模具的整体结构。设计了可相对运动的组合式型芯,以增加内抽芯机构的运动空间,通过塑件推出时带动螺纹滑块的移动实现了内侧抽芯。设计了矩形型芯镶块、加工了避空结构,采用螺钉固定,解决了狭小空间安装小型芯的问题,避免了模具干涉。采用了锥面配合,提高了模具的定位精度,减小了配合件的摩擦。经生产验证,该模具生产的塑件质量满足图纸要求。