钢结构用高强度螺栓及其连接

除焊接、铆接和六角头(普通)螺栓连接以外,高强度螺栓连接也是钢结构的另一种重要连接方式。高强度螺栓有8.8S级、10.9S级和12.9S级三种。我国目前使用的高强度大六角头螺栓只有8.8S级和10.9S级两种,扭剪型高强度螺栓只有10.9S级一种。该文对高强度螺栓及其连接作了比较,并提出了注意事项。     

直臂式转台倾覆事故分析及处理方法

介绍了转台的基础连接方式，着重分析了T型高强螺栓在设计和制造中存在的问题，以及造成螺栓断裂、连接失效和转台倾覆的主要原因及事后的处理方法。     

包钢2号高炉框架柱梁制造

2号高炉框架柱、梁使用钢结构扭剪型高强螺栓副连接.总高25 570 mm,采用两段制造,直线组装焊接方法,保证了直线不直度符合要求;采取机械、火焰矫正方法,保证悬挑梁与相应框架梁高强螺栓连接端面高度差≤1 mm;用"滚动"预装方法,把立体转化为平面组合;保证四根立柱间距为正方形,对角线差小于5 mm;立柱与四根横梁所在平面垂直;框架和平台在工地用高强螺栓顺利把合.     

球磨机筒体与衬板连接方法的改进

许多选矿厂是用螺栓连接球磨机筒体和衬板的。这种连接方法,在螺栓头磨损完了,衬板就会掉下来,需要更换新衬板。我厂的φ1200×1200毫米球磨机使用平滑式衬板(6厘米)。衬板与筒体是用螺栓连接,当衬板磨损约4厘米时,螺栓头便磨损掉了,因此需要更换新衬板。今年三月,我们将螺栓连接改用揷销连接(见图),即在衬板翻砂时,铸成两个有孔的小圆柱。在     

回转轴承螺栓连接分析

通过对连接螺栓预紧力的分析，讨论了载荷、环境温度对高强度螺栓的影响，确定了高强度螺栓连接预紧力许用上限值分析，优化了安装方案，提高了螺栓的强度，为今后现场复核高强度连接螺栓的预紧力是否为最佳状态提供了理论依据。     

限动齿条连接的设计改进

分析了螺栓连接的限动齿条在使用过程中出现的问题。以天津钢管公司168机组限动齿条连接改造为例,在分析计算后,将螺栓连接形式改进为哑铃型连接形式。热模拟有限元分析及现场使用验证结果表明:与螺栓连接限动齿条相比,哑铃型限动齿条连接的使用可靠性及后期维护方面更佳,备件数量可以减少,生产效率得到提高。     

高强度螺栓连接副的检测技术

大六角头高强度螺栓连接副扭矩系数的检测,扭剪型高强度螺栓连接副坚固预拉力的检测,高强度螺栓连接磨擦面抗滑移系数的检测,是钢结构材料验收中的重要测量.这些渐渐兴起的检测技术,对钢结构工程施工质量的监督具有重要的意义.     

中国轻型化镁部件的技术连接

前言Foreword汽车工业的强化轻型化设计鼓励使用镁作为铸造材料。对于压铸部件设计来讲,镁是目前最轻的金属材料,镁具有合适的机械和物理性能并且被大部分汽车部件所采用,因为薄壁压铸件采用镁材料具有良好的可铸性。镁外壳部件、镁梁和加劲部件采用螺栓连接来安装,从传统意义上讲铝和钢部件采用高抗拉强度紧固体,紧固体采用碳素钢制成在连接安装上不存在问题,但高抗拉3号紧固件和镁部件一起使用都经历了各种挑战。基本设计连接原则是“采用螺栓断裂损坏型的连接失效”。这一基本原则对于镁部件的连接也适用和有效,因此钢紧固件要求较高的…     

球磨机端盖法兰连接螺栓的断裂原因及其解决

对氧化铝生产流程中溶出工艺使用的QS-2736溢流型球磨机（溶出磨）端盖法兰连接螺栓出现断裂的问题进行分析,并提出相应的解决方法和预防措施。     

钢包回转台高强度连接螺栓的脆断分析与设计改进

本文介绍了钢包回转台高强度连接螺栓在静载低应力状态下脆断的实例，证实了断裂原因是由于高强度合金钢裂纹敏感型突发性脆断所致。并对钢包回转台高强度连接螺栓的设计提出了改进意见。     

高强度螺栓延伸法预紧的实际预紧力研究

采用液压延伸法对螺栓联接进行预紧是一种快捷经济的预紧方法。该法一般通过控制拉伸量或拉伸力来保证螺栓的预紧。应用传统的计算方法难以准确地计算采用延伸法预紧后螺栓的实际预紧力,而运用有限元技术对螺栓的预紧过程进行仿真,准确可靠地计算了螺栓的实际预紧力。     

解体式钢水罐回转台螺栓强度有限元分析

采用Inventor三维建模软件建立了某360t解体式钢水罐回转台三维实体模型,利用ABAQUS有限元软件对连接座与回转支撑台之间的连接螺栓和底座与基础之间的地脚螺栓进行了有限元静力分析。通过对连接螺栓和地脚螺栓在施加螺栓预紧力和不施加预紧力的情况下局部区域的精细分析,给出了两种状态下螺栓连接区域的应力分布和变形,得到螺栓预紧力足够的结论,同时指出不施加螺栓预紧力会导致连接区域的分离,这在工程中是不容许的。     

Strength of Glued-In Bolts after Full-Scale Loading

In 1993 after 9 years of use, one of the wooden blades of a windmill was struck by lightning. After demounting, the damaged blade was handed over to the Technical University of Denmark, Lyngby, for the investigation of potential fatigue damage. This paper presents an experimental determination of the residual strength of the glued-in bolts that served as the blade to rotor hub connection in the windmill. The load history of the bolts, the test method, the observed fracture modes, and the force displacement curves are presented along with the recorded residual strength of the bolts. The bolts with a length of 500 mm had a special hollow tapering giving them a higher load-bearing capacity than solid bolts of equal dimensions. An FEM analysis confirms the higher load-bearing capacity. The mean residual stength was found to be 362 kN with a standard deviation of 37 kN, which is 95% of the predicted strength based on short-term tests on similar bolts. At fracture, a displacement between 0.4 and 1.0 mm was observed. In the majority of failures, the bolts were pulled out like a cork from a bottle.     

桥式起重机主端梁连接计算分析

对桥式起重机主端梁的连接形式加以介绍,着重对该处的连接螺栓进行了分析计算,并得出结论。     

特殊螺纹接头上扣过程仿真分析

在试验和有限元分析的基础上,介绍了特殊螺纹接头上扣扭矩曲线与接头结构的关系,并完成了宝钢BGT2系列196.85×12.7 mm BG140V BGT2套管气密封特殊螺纹接头的上扣过程的模拟。参照ISO13679(2002)标准要求,针对不同的几何尺寸组合分别建立有限元模型,并分析其上扣过程扭矩曲线变化,探讨了不同尺寸参数对扭矩曲线形状的影响;同时利用有限元模型计算了该规格产品的屈服扭矩和上扣过程接触力变化。通过与实物试验的对比,验证了该分析结果的可靠性,从而为产品开发和使用提供指导。     

重力式热管换热器串联组件的实验研究

提出的新型重力式热管换热器的结构，是用以解决在余热回收系统中换热装置低温酸露点腐蚀问题。本技术的核心问题就是采用热管串联组件。这种组件可以使前后热管壁温分布均匀，提高在低温下抗酸腐蚀的能力。实验表明，即使人口烟气温度较低，烟气侧热管壁温仍然较高。     

Coordinated morphogenesis of epithelia during development of the Caenorhabditis elegans uterine-vulval connection

Development of the nematode egg-laying system requires the formation of a connection between the uterine lumen and the developing vulval lumen, thus allowing a passage for eggs and sperm. This relatively simple process serves as a model for certain aspects of organogenesis. Such a connection demands that cells in both tissues become specialized to participate in the connection, and that the specialized cells are brought in register. A single cell, the anchor cell, acts to induce and to organize specialization of the epidermal and uterine epithelia, and registrates these tissues. The inductions act via evolutionarily conserved intercellular signaling pathways. The anchor cell induces the vulva from ventral epithelial cells via the LIN-3 growth factor and LET-23 transmembrane tyrosine kinase. It then induces surrounding uterine intermediate precursors via the receptor LIN-12, a founding member of the Notch family of receptors. Both signaling pathways are used multiple times during development of Caenorhabditis elegans. The outcome of the signaling is context-dependent. Both inductions are reciprocated. After the anchor cell has induced the vulva, it stretches toward the induced vulval cells. After the anchor cell has induced specialized uterine intermediate precursor cells, it fuses with a subset of their progeny.     

Reinforcing Transverse Glulam Deck Panels with Through-bolted Glulam Stiffener Beams: Theoretical Analysis

Two design criteria, allowable stress design (ASD) and load and resistance factor design (LRFD), are presented for calculating glued-laminated (glulam) stiffener beam depth and number of dome head through bolts used in deck-to-deck connections for longitudinal stringer, transverse deck glulam bridges. Design examples for six deck panel spans (762–3,658 mm) and an applied 89 kN wheel load are also presented. The connection configurations (stiffener beam depth and number of dome head bolts) for both ASD and LRFD differ only in the stiffener beam depth (maximum 15% difference). Both ASD and LRFD criteria performed very well when compared to experimental observation and results of loaded stiffener beam connected deck panels.     

自然补偿热力管系在设备端点附近的有效限位方式

在有端点附加位移的自然补偿管系设计中,端点附近的限位方式对端点推力值有直接影响,为有效降低管道对设备的推力,利用管系自身热变形量来吸收端点附加线位移,本文探讨了端点附近的有效限位方式,并用通过实例计算对不同限位方式所产生的端点推力进行比较,以选择最有效的限位方式。     

邯钢60MW汽轮机安装实践

介绍了邯钢60MW汽轮机垫铁布置、地脚螺栓的安装、汽缸找中心、各转子间联轴器找中、大口径管道连接、油系统冲洗及验收标准等,对同类型发电机组汽轮机的安装和检修具有一定的参考价值。