Uncertainty analysis of notch stress concentration factors for welded butt joints [PDF]
ObjectivesThis paper focuses on parametric modeling of a typical butt joint and establishes a finite element model with uncertain geometry of the weld seam, aiming to investigate the stress concentration factor Kt at the weld toe of the butt joint with ...
Chunbo ZHEN +4 more
core +1 more source
Shiyou jixie, 2012 针对应力集中导致石油钻杆螺纹产生疲劳裂纹，进而发生断裂失效的事故，在API接头的基础上，研究开发了一种新型钻杆螺纹接头，该新型螺纹结构主要改进之处是内螺纹锥度保持1:6不变，外螺纹锥度变为1:6.23。有限元分析结果表明，这种螺纹形式显著改善了接头上的受力分布情况，使得螺纹上应力分布更加均匀，并降低了主台肩过渡圆角处的应力集中。对样品的上扣试验结果表明，采用新型螺纹后，外螺纹接头主台肩底部的过渡圆角处应力集中情况也得到明显改善，接头整体受力分布和不同区域应力差更趋平缓 ...
焦文鸿, 高连新, 鲁喜宁
doaj
Study on Preparation and Application of Adhesive for Polyolefin Film [PDF]
, 2015 由于具有较高的机械强度、良好的化学稳定性、较好的电绝缘性、优良的加工性等优势，聚烯烃塑料广泛应用于社会生活中。在众多的聚烯烃塑料制品中，最为常见的产品是薄膜制品，包括聚乙烯薄膜、聚丙烯薄膜、多层共挤聚烯烃薄膜等。为了获得更优异的性能，实际应用中一般将聚烯烃薄膜与自身或者其他薄膜（如铝箔、聚酰胺薄膜、聚酯薄膜等）进行复合使用。目前，在复合过程中常用的聚烯烃薄膜粘结剂存在以下两个问题：1、环保问题：目前国内广泛使用的酯溶型聚氨酯粘结剂可能含有异氰酸酯单体的残留，而水性粘结剂由于干燥速度慢 ...
谢东权
core
Mechanism of rock burst induced within the fully mechanized top coal caving face with overlying knife-shape-like gob and hard thick roof [PDF]
Irregular upper gobs may increase the risk of rock burst incidents in coal mines. Investigating the rock burst mechanism in the complex mining spatial structure of multi-seam rock bursts is essential for ensuring the safe extraction of coal resources ...
Chao ZHOU +6 more
core +1 more source
Failure characteristics and control technology of “L-shaped” isolated island working face inroadway inflection point area [PDF]
Pillar free mining technology is widely used in coal mining field in China. After the formation of isolated island working face, it is affected by strong mining movement, which leads to the phenomenon of large deformation and instability of mining ...
Hui WANG +3 more
core +1 more source
Shiyou jixie, 2015 随着服役年限的增加，导管架海洋平台结构将产生缺陷和损伤。金属磁记忆技术可实现对铁磁性金属构件内部应力集中区的检测，因此可用于对导管架平台结构的应力集中检测。在介绍金属磁记忆检测机理后，将该技术应用到导管架平台结构预检测上，并以CEP导管架平台上部组块为对象开展了应力集中检测。经与超声检测结果对比，验证了金属磁记忆技术在导管架平台结构检测的适用性。研究结果表明，金属磁记忆检测能快速准确地对平台结构进行应力集中检测，其检测结果可为平台年检计划的制定提供依据和参考。
王宁, 吕涛, 徐长航, 陈国明
doaj
Damage characteristics and support optimization of roadway surrounding rock in near-vertical coal seams under combined dynamic and static loads [PDF]
Currently, most research on rock burst prevention and control focuses on horizontal and gently inclined coal seams. However, due to the unique occurrence characteristics of near-vertical coal seams, the characteristics of rock burst in these seams are ...
FENG Panfei +3 more
core +1 more source
Temporal and spatial evolution law of microseisms and induced impact mechanism in complex spatial structure area of steep and extremely thick coal seam [PDF]
The occurrence of coal mine rock burst disasters is closely related to the spatial structure, especially in the complex spatial structure area. It is of great significance to master the law of coal and rock catastrophe and reveal its mechanism in the ...
Changliang LU +8 more
core +1 more source
基于Pro/E Mechanica的农业机械用链轮的动力学分析
Jixie chuandong, 2015 链传动由于其传动可靠、结构简单,在农业机械中获得广泛应用。在工厂化水产养殖中应用的链斗式过滤装置中,作为链传动中关键零件,链轮受到工作环境恶劣、复杂载荷等因素影响,齿根磨损严重而失效。为增加链轮寿命、减少应力集中,利用Pro/E平台建立链轮的三维模型,并应用Pro/E Mechanica进行动力学分析,进行链轮设计的结构优化,在减轻其重量的同时,使链轮受力基本均匀,减少应力集中和变形。通过对链轮做全局敏感度分析表明:齿顶圆弧半径的增加削弱了最大应力的增长;最大应力随凸缘直径的增加而减小 ...
程启云 +4 more
doaj +1 more source
Dianci bileiqi, 2016 针对一起500 kV线路玻璃绝缘子集中破碎8片现象,进行了污秽度测量、成份分析、泄漏电流测量以及火花放电观察。结合运行环境和天气,认为玻璃绝缘子在污秽中成份金属离子和金属氧化物含量比较高,导致绝缘子串上产生长期工频泄漏电流和火花放电。长期工频泄漏电流和火花放电产生的电应力使得玻璃件损伤和钢化层破坏;污秽分布不均以及下雨天气,导致泄漏电流和火花放电集中在污秽严重一侧,玻璃件产生温差,从而产生热应力;在电应力和热应力的共同作用下,最终导致了本次集中破碎。
马御棠 +7 more
doaj