Results 21 to 30 of about 512 (141)
Gaoya dianqi, 2021 针对一起500 kV断路器爆破片破裂事故,通过对破裂爆破片开展理化检验,发现故障爆破片材质为灰铸铁,表面有微孔,双侧用橡胶层密封保护,没有锈蚀,电镜分析表明材料脆性较大。通过更换同型断路器爆破片,比较新旧爆破片的性能,发现旧爆破片均有变形,大部分旧爆破片外侧橡胶层老化龟裂,导致爆破片进水锈蚀。通过开展爆破试验,发现部分旧爆破片爆破压力降低,但并不是锈蚀严重的样品。结果表明锈蚀并不是导致爆破片爆破压力下降的关键原因,该爆破片为平板型,铸铁材质,脆性较大,抗疲劳性能不足 ...
焦宗寒, 郑欣, 马宏明, 宋玉锋
doaj
Z-direction Enhancing Manufacturing Strategy for 3D Printing Prosthetic Socket of Continuous Fiber Composite [PDF]
, 2022 The prosthetic socket is a necessary rehabilitation-aid equipment for lower limb amputees. As an important kind of human-machine interface between the residual limb and the prosthesis, the prosthetic socket plays an important role in containing the ...
Li, D +7 more
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Experimental investigation on fracture behavior of lignite and its fracturing significance:taking Shengli Coalfield as an example [PDF]
, 2023 The anisotropy of fracture properties at different bedding orientations of lignite plays an important role in controlling the formation of fracture network of reservoir racturing.
Diankun ZHANG +2 more
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Development of a Two-dimensional Ultrasonic Vibration Assisted Grinding Technique of Monocrystal Silicon [PDF]
, 2010 基于超声振动磨削能有效提高加工效率及加工表面质量的特性,通过设计具有伸缩和弯曲两种模态的压电陶瓷椭圆振子,实现了单晶硅二维椭圆振动磨削技术。对超声振子的振动特性进行检测,证实改变压电陶瓷两电极之间的交流信号相位差和电压幅值,可得到不同形状和振幅的椭圆振动。对单晶硅进行超声磨削与普通磨削的对比试验,结果表明二维振动磨削的磨削力大幅降低,表面粗糙度显著减小,表面质量明显提高,加工表面延性域去除比例增加。从而证实二维超声振动磨削方法能够实现高效率高质量单晶硅加工。Based on the ...
吴勇波 +5 more
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Gaoya dianqi, 2022 电缆终端在湿热沿海地区运行过程中会偶发法兰、螺栓断裂的机械故障，对电缆的安全运行产生严重的威胁。为了分析螺栓断裂机理和螺栓受力特性，文中分析了断裂螺栓的拉伸性能、化学成分变化、金相显微组织和表面形貌特征，然后通过有限元法对电缆终端中螺栓的应力应变特征进行了分析。研究表明断裂螺栓化学成分不符合标准，机械性能和抗腐蚀性能显著较差；在役电缆终端螺杆中部位置有较大的应力和形变量，是螺栓脆弱部位；因此，在沿海高湿热高盐雾环境作用和螺栓高应力作用发生应力腐蚀，螺杆中部表面位置腐蚀最快并最先出现裂纹，然后向里扩展 ...
范伟男, 王勇, 李光茂, 杜钢
doaj
Simulating hydrogen embrittlement fracture based on phase field method
Xibei Gongye Daxue Xuebao, 2022 The phase field hydrogen embrittlement fracture model is improved by introducing tension-compression split of strain energy. The numerical formulas of the model are provided, besides, the coupling term of concentration field and displacement field is ...
CHEN Pengcheng +3 more
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Gaoya dianqi, 2021 复合绝缘子断串及芯棒击穿事故会对输电线路的安全稳定运行构成严重的威胁。文中对2016年以来浙江省内发生的复合绝缘子断串及芯棒击穿故障案例进行统计分析,包括故障概况、产品情况、故障形态、性能试验、故障原因以及相关建议措施等。结果表明,2016年以来浙江省内共发生8起复合绝缘子断串及芯棒击穿故障,包括6起酥朽断裂、1起脆性断裂及1起芯棒击穿。其中,脆性断裂主要为端部密封不良,外部潮气进入,并在长期高场强作用下产生的应力腐蚀所致;酥朽断裂主要为芯棒—护套粘接不良,在受潮、放电 ...
周晨 +5 more
doaj
Research status and progress of hydrogen embrittlement of hydrogen pipelines [PDF]
, 2023 Hydrogen transportation through pipelines has extremely high economic value in realizing the development of the hydrogen energy industry and promoting efficient energy utilization.
Hongliang MING, Jianqiu WANG, Jianwei DU
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Dizhen xuebao, 2020 基于首都圈数字地震台网的宽频带资料，首先采用CAP方法确定了永清MS4.3地震和廊坊MS3.0地震的震源机制解：永清地震节面Ⅰ的走向、倾角和滑动角分别为52°，62°和−140°，节面Ⅱ的走向、倾角和滑动角分别为300°，55°和−35°；廊坊地震节面I的走向、倾角和滑动角分别为48°，57°和−147°，节面Ⅱ的走向、倾角和滑动角分别为299°，63°和−38°。两次地震的震源机制解较为一致，推测它们可能具有相同的发震断层。利用近震转换波获得两次地震的震源深度，分别为19 km和13 km ...
He Li +4 more
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Analysis on the fracture failure in crack interaction of mortar using the phase-field method [PDF]
, 2016 This article introduces a new mortar fracture analysis method based on the phase-field method,which is used to analyze the fracture failure in crack interaction of mortar.The non-conserved Allen-Cahn equation was adopted as the system governing equation ...
GE Zhi +4 more
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