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71.
锥形形状记忆合金阻尼器性能分析与试验研究 总被引：1，自引：1，他引：0
本文对一种新型形状记忆合金阻尼器——锥形形状记忆合金阻尼器的性能进行了数值分析和试验研究。基于形状记忆合金的超弹性双线型本构模型,利用非线性有限元方法分析了锥形形状记忆合金阻尼器的滞回性能,并且用大型能用程序ANSYS进行了验证,得出锥形形状记忆合金阻尼器的滞回模型可简化为分段线性滞回模型,试验包括形状记忆合金丝的本构试验、疲劳试验阳阻尼器的性能试验．试验结果与数值分析结果基本吻合,形状记忆合金表现出良好的超弹性。 相似文献
72.
深井复合钻柱技术是解决特深科学钻探超长钻杆柱可靠性问题的重要途径,其与设备能力、材料性能、钻进条件及管柱力学等息息相关。本文系统总结了复合钻柱技术在我国深部钻探中的发展和应用情况,在复合钻柱强度理论的基础上,探讨了不同复合钻柱的组合方案及其极限下深。研究结果表明,若以?216 mm直径终孔,仅依靠钢质钻柱已无法满足特深钻探13000 m的下深要求,而采用V150钢级?127 mm钻杆配合?127 mm钛合金钻杆及S135钢级?127 mm钻杆配合?129 mm铝合金钻杆可分别满足最大13484 m和18783 m的下深要求,钻柱总重分别仅有360.5 t和324.3 t,均具备可靠的安全性保障。本文对特深科学钻探用复合钻柱的设计和选择具有参考意义。 相似文献
73.
与传统的钢制钻杆相比,铝合金钻杆具有密度小、比强度高、无磁等优点,因此在深井与超深井钻井作业中具有较大优势。在实际使用中,铝合金钻杆两端需要通过钢接头之间的螺纹来实现拧卸钻杆,而铝合金杆体与钢接头还需要过盈装配以实现紧固连接 。以液氮为冷源,对50 mm的7075铝合金钻杆管体与钢接头进行了“冷组装”过盈装配,铝合金管体与钢接头之间的过盈量分别为0.10、0.15、0.20 mm。对组装后两端带钢接头的铝合金钻杆分别进行了拉伸和扭转试验,评价了铝合金管体与钢接头连接的可靠性,对断裂试样的断口进行了宏观与微观分析,阐述了其断裂机理。结果表明,采用“冷组装”方式可以实现铝合金管体与钢接头的过盈装配,其中过盈量为0.15 mm时,带钢接头的铝合金钻杆综合性能较优,可以承受较大的抗拉强度极限和抗扭极限,其断裂方式为脆性断裂。 相似文献
74.
The welding was one of the technologies to manufacture manned cabin, which was a significant part of the submersible. To improve the procedure, horizontal EBW was employed on TC4 ELI alloy with 60 mm thickness, and the microstructures and properties of the joints were investigated. The crystals and microstructures of the welds were homogeneous from the top to bottom, and the microhardness of the weld was equivalent, which was harder than that of the base metal. The tensile properties of the joints were homogeneous along the penetration. The tensile strength and yield strength of the joints were higher than those of the base metal, and the percentage elongation after fracture was 80% of the base metal, which indicated the strength mis-match as overmatching. The impact toughnesses of the welds were equivalent along the penetration, which reached 80% of the base metal. The joint specimens were bended to 180° with no cracks. The investigation verified the excellent procedure and properties of horizontal EBW, which would make China become one of the countries with the capacity of manufacturing submersible cabin. 相似文献
75.
针对半刚接钢框架-混凝土墙(PSRCW)结构中连接件易发生疲劳断裂的问题,利用形状记忆合金(SMA)制成连接件并将其应用到PSRCW结构中。对4个2层单跨PSRCW结构试件在水平低周往复荷载作用下的抗震性能进行了试验研究。根据试验现象分析了各试件的受力破坏过程,研究了连接件类型、尺寸和布置位置对各试件的滞回性能、耗能能力、强度、刚度、延性和变形恢复能力的影响。试验结果表明:基于SMA连接件的PSRCW结构整体性较好、耗能能力强、结构强度退化具有2个平台阶段、刚度退化较为缓慢、延性好和结构具有较强的变形恢复能力。同时,增大SMA连接件的直径可以提高结构的承载能力、初始刚度和延性;在框架梁柱与内填墙交界面间均布置SMA连接件时,结构整体性最好,强度退化缓慢,延性好。因此,将SMA连接件应用于PSRCW结构中,对于改善钢混组合结构的力学性能有一定的理论意义和实用价值。 相似文献
76.
Given their excellent self‐centering and energy‐dissipating capabilities, superelastic shape memory alloys (SMAs) become an emerging structural material in the field of earthquake engineering. This paper presents experimental and numerical studies on a scaled self‐centering steel frame with novel SMA braces (SMAB), which utilize superelastic Ni–Ti wires. The braces were fabricated and cyclically characterized before their installation in a two‐story one‐bay steel frame. The equivalent viscous damping ratio and ‘post‐yield’ stiffness ratio of the tested braces are around 5% and 0.15, respectively. In particular, the frame was seismically designed with nearly all pin connections, including the pinned column bases. To assess the seismic performance of the SMA braced frame (SMABF), a series of shake table tests were conducted, in which the SMABF was subjected to ground motions with incremental seismic intensity levels. No repair or replacement of structural members was performed during the entire series of tests. Experimental results showed that the SMAB could withstand several strong earthquakes with very limited capacity degradation. Thanks to the self‐centering capacity and pin‐connection design, the steel frame was subjected to limited damage and zero residual deformation even if the peak interstory drift ratio exceeded 2%. Good agreement was found between the experimental results and numerical simulations. The current study validates the prospect of using SMAB as a standalone seismic‐resisting component in critical building structures when high seismic performance or earthquake resilience is desirable under moderate and strong earthquakes. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
77.
锗的重要迁移形式——锗氢化物 总被引：2，自引：0，他引：2
经对锗及其氢化物的物理化学性质、有关矿床矿物流体包裹体化学成分、主要含锗矿物及锗矿物的化学成分、内生锗矿物的共生伴生矿物特征等相关问题的研讨,认为锗氢化物、锗合金氢化物是锗成矿的重要迁移形式。 相似文献
78.
XIAO Yuanfu SUN Yan LU Yan WEN Chunqi WANG JiangzhenDepartment of Geology Chengdu Institute of Technology Shilidian Chengdu Sichuan Zhu Xiling 《《地质学报》英文版》1998,72(3):308-313
Zinccopperite (tentatively named) is a rare native alloy mineral discovered in quartz monzonite-porphyry in the Xifanping area, Yanyuan County, Sichuan Province. It is a new variety of zinc-copper alloy mineral found for the first time in the porphyry-copper deposit in China. Its intergrown minerals are K-feldspar (mainly perthite), albite-oligoclase, quartz and biotite; and the associated minerals include pyrite and chalcopyrite. It is characterized by a golden reflection colour, being isotropic (isometric), with the grain size ranging from 10 to 50 μm, microhardness VHN10= 190 kg/mm2, and reflectance RVis= 67.97%. Electron microprobe (Model JXA-733) analysis shows Cu = 59.15%-62.55% and Zn= 36.32%-39.85%. The crystallochemical formula is Cu6.27-7.0Zn4.0, simplified as Cu7Zn4. 相似文献
79.
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