Results 71 to 80 of about 786 (139)
Analysis of dynamic splitting tensile failure and energy evolution characteristics of Jinping marble [PDF]
Splitting tensile failure is one of the main forms of instability failure of tunnel surrounding rock. At present, the mechanisms of rock crack propagation and energy evolution at the corresponding stages under dynamic splitting conditions have been ...
Fengchen MIAO +4 more
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Advancements and future prospects in the fundamental theories of rock blasting research Ⅱ—Dynamic–static relationship [PDF]
Blasting is a process in which the chemical energy of explosives is rapidly released, causing strong impact on the rock mass and achieving efficient rock fragmentation.
Chenxi DING +6 more
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Study on mechanical properties, fatigue properties and He+ irradiation behavior of SA508 Gr.3 Cl.1 steel made in China [PDF]
, 2017 SA508Gr.3Cl.1钢是用于制造核电压力容器的主要候选材料，属于不可替换的构件，其寿命决定了整个核电厂的寿命。本论文根据相关国家标准对国产SA508Gr.3Cl.1钢的微观组织、力学性能、疲劳性能和氦离子辐照行为进行了研究与评估。采用光学显微镜、扫描电子显微镜和透射电子显微镜对原始态SA508Gr.3Cl.1钢的微观组织结构进行了观察、分析与表征。通过硬度试验、冲击试验、拉伸试验以及对试样断口的分析，综合评价了SA508Gr.3Cl.1钢的力学性能。测试与分析了SA508Gr.3Cl ...
王驰
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Gaoya dianqi, 2019 绝缘管型母线是一种新型的母线产品,有着优异的性能。但应用时间较短,研究不够深入,致使故障频发。文中设计与制备了含气泡缺陷环氧浇注绝缘管型母线真型样品,通过加压电破坏试验,研究其电击穿机理。在试验中首次发现了气体膨胀鼓包导致最终击穿的破坏方式。研究结果表明,电—机械击穿应为其击穿模式,其击穿过程可分为气体增强阶段和击穿临界阶段两个阶段,并得到了阶段特征与阶段变化判据。气隙内由局部放电导致环氧树脂分解所产生的气体气压超过气隙壁断裂韧性临界值,造成裂纹失稳扩展是击穿的主要原因 ...
任想 +6 more
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Three-dimensional omnidirectional characterization methods of rock anisotropic wave velocity and acoustic emission location optimization [PDF]
Rock failure and instability have been key research topics in rock mechanics domestically and internationally. Numerous geotechnical disasters, such as rock bursts and slope instability, are associated with these phenomena. Acoustic emission detection is
Conghao LI +5 more
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Shiyou jixie, 2012 以Φ114.3 mm整体式方钻杆旋塞阀为例，采用CFD软件对其速度场和压力场进行数值模拟研究，以揭示流场的速度和压力分布，弄清流体在球阀关闭过程中的变化规律。建模时采用有限体积法对控制方程进行离散，用Quick格式处理对流项，压力修正采用二阶格式，方程组的求解采用分离求解和Simple算法。研究结果表明，旋钮水平面处的作用力存在3 MPa差异，增加了该处的疲劳损坏，使得裂纹沿水平面扩展；方钻杆旋塞阀的失效形式均与流场数值模拟计算结果一致，说明流场数值模拟结果是正确的。
冯文荣, 曹佳, 朱海燕, 冯勇
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, 1995 为解决石油平台在辽东湾海域的低温疲劳问题，借助ＭＴＳ试验机，建立一套低温疲劳实验系统，实现了低温疲劳实验中疲劳裂纹的观察和测量，以获取平台结构钢在低温下的疲劳裂纹扩展速率的可靠数据 ...
张兴钧 +4 more
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Jixie chuandong, 2014 With the development of the modern detection technology,carrying out the gear life prediction with initial crack is of great significance to power transmission device in special situations and precision predict the gear life.Based on the theory of linear
吴金亮, 汪中厚, 李刚
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Research review of the mechanism and influencing factors in dissociative adsorption of hydrogen on pipeline steel surface [PDF]
Objective Hydrogen energy has drawn significant attention as the strategy of energy transition pushing forward, making it essential to establish reliable hydrogen transmission systems.
Yulin SONG, Yuxing LI
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Dianci bileiqi, 2017 电瓷的无机粘接及对其表面进行少量的无机修复,都需要进行多次烧成,但对多次烧成对其性能的影响却缺少系统的讨论。本文将试条随同批电瓷产品进行多次烧成,通过测量试条的抗折强度及其强度分散性、显微结构特征及物相成分,讨论了多次烧成对电瓷机械性能的影响。结果表明:随着试条烧成次数的增加,抗折强度有小幅度下降,且强度分散性增大,上釉坯体中这种现象更明显。多次烧成后,晶体异常长大现象并不明显,但石英颗粒周围存在着微裂纹增多且出现扩展现象;主晶相莫来石-石英的量有一定程度减少,且析出了少量方石英相 ...
徐小燕 +4 more
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