Results 11 to 20 of about 32,678 (200)

H形钢梁疲劳裂纹扩展过程数值模拟

open access: yesJianzhu Gangjiegou Jinzhan, 2022
采用基于断裂力学的有限元法对焊接H形钢梁的疲劳裂纹扩展过程进行了数值模拟。给出了模型的基本假定:初始裂纹为半径1.016 mm的圆形、裂纹中心位于受拉翼缘与腹板之间焊缝焊根处、裂纹前缘由3~4段1/4椭圆弧线控制、在裂纹前缘端点处与内部点处分别采用不同的Paris公式系数、以疲劳裂纹深度穿透受拉翼缘壁厚或SIF超过断裂韧性为循环终止条件。采用二次多项式外推插值的方式对H形钢梁裂纹前缘端点处以及紧邻端点的个别结点处直接输出的应力强度因子(SIF)计算值进行了修正。通过试验验证 ...
肖顺, 童乐为
doaj  

桥体钢箱梁疲劳裂纹拍摄小车的6 自由度运动实现方式

open access: yes工程技术研究, 2020
在对桥体钢箱梁内部疲劳裂纹进行检测后,论文中介绍了一种可将相机送入合适位置自动拍摄的拍摄小车以及拍摄小车控制相机 6 自由度的运动实现方式。
旭 王, 信仁 贾
semanticscholar   +1 more source

高速公路裂纹分析与防治措施研究

open access: yes智能城市应用
随着高速公路交通量的不断增加和交通荷载的不断加重,裂纹问题成为影响道路质量与安全的重要因素之一。裂纹不仅影响道路的使用寿命,还直接关系到行车安全。针对高速公路上裂纹的成因进行深入剖析,文中探讨了裂纹形成的基本原理,并基于现有裂纹防治技术,综合提出了科学合理的防治策略,对裂纹进行分类探讨,深入研究其检测与加固技术。文中提出了一套涵盖预防、修复、材料选材、施工质量把控等多维度的全面防治策略。通过具体案例及对比试验,证实了所提策略在提升道路品质、拉长使用年限及减少维护费用上的实际效用,高速公路裂纹控制研究 ...
睿龙 赵
semanticscholar   +1 more source

体心立方Fe中 \begin{document}${ \langle 100 \rangle}$\end{document} 位错环对微裂纹扩展影响的分子动力学研究

open access: yes, 2020
在辐照环境下, 载能粒子与材料相互作用导致材料中原子移位, 造成辐照损伤. 其中, 由辐照形成的过饱和自间隙原子团簇形成的间隙型位错环, 是体心立方Fe为基的材料中常见的辐照缺陷之一, 其与材料中其他缺陷之间相互作用, 是导致辐照硬化、脆化、肿胀及蠕变等辐照损伤的原因之一. 除此相互作用外, 在材料表面或内部沿晶界、沉积相、惰性气体形成的气泡所导致的微裂纹, 是诱发辐照促进应力腐蚀开裂的重要原因. 因此, 理解辐照条件下间隙型位错环与微裂纹之间的相互作用, 是理解辐照促进应力腐蚀开裂微观机制的重要一步.
梁晋洁, 高宁, 李玉红
semanticscholar   +1 more source

高压断路器瓷套裂纹尖端应力强度因子研究

open access: yesDianci bileiqi, 2020
针对三维裂纹尖端应力强度因子计算困难的现状,提出了一种新型的三维裂纹应力强度因子计算方法,通过与其它方法在计算含圆孔平板裂纹尖端应力强度因子的对比分析,验证了本文应力强度因子计算方法的有效性和优越性。建立含裂纹缺陷的高压断路器瓷套有限元数值模型,将本文方法应用于高压断路器瓷套裂纹的应力强度因子计算,研究了高压断路器瓷套表面裂纹应力强度因子与瓷套所处环境温度、裂纹分布位置和裂纹尺寸的变化关系,获得了易导致瓷套断裂的环境、裂纹分布位置和裂纹尺寸,为电力行业中断路器瓷套的设计及运行维护提供有效的技术指导和借鉴。
赵滨滨, 王莹, 徐晓萌, 崔文婷
doaj  

Designing Additive‐Manufactured High‐Performance CoCrNi Matrix Composites Based on Grain Boundary Segregation

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Through grain boundary segregation engineering, a crack‐free high‐strength CoCrNi medium‐entropy alloy (MEA) can be successfully fabricated via laser powder bed fusion (PBF‐LB). The influence of micron‐sized TiC particles on microstructural evolution, grain boundary segregation behavior, and mechanical properties was systematically ...
Cunliang Pan   +9 more
wiley   +1 more source

动态裂纹扩展中的裂纹滞留现象 [PDF]

open access: yes, 1997
该文研究了裂纹前方开始环绕和穿透介质中各种粗糙微粒而形成粗糙的裂纹表面等非稳定现象. 数值结果表明: 在I型情形, 振荡性裂纹前缘运动源于应力强度波的建设性——破坏性相互作用.
孟宪红, 李湘平, 王凯, 柳春图
core  

Microstructure Characteristics and Strength–Ductility Mechanisms of a Novel Neutron Shielding Al‐6Mg‐5Gd Alloy Fabricated by Laser Powder Bed Fusion

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Al‐based neutron shielding materials suffer from poor laser powder bed fusion (LPBF) processibility, hindering their simultaneous achievement of good printability and exceptional mechanical properties. In this work, the newly developed rare‐earth Al alloy (i.e., Al‐6Mg‐5Gd) was processed by LPBF technique to meet the printability, mechanical ...
Chen Yang   +8 more
wiley   +1 more source

Superior Abrasibility of YSZ(ESP)/BN@ZrO2‐Polyester Composite Sealing Coating Reinforcing With Hybrid Micron/Nanometer Multiscaled Pore Structure

open access: yesRare Metals, Volume 45, Issue 5, May 2026.
ABSTRACT Composite materials hold significant potential for abrasive sealing, yet composite materials used for abrasive sealing fall short in service durability under extreme environments. Here, a controllable strategy for adjusting pore structure is proposed, aiming to design a YSZ(ESP)/BN@ZrO2‐polyester coating with hybrid micron/nanometer ...
Shuang Yu   +8 more
wiley   +1 more source

Complexion‐Mediated Dislocation Transfer Enables Exceptional Strength‐Toughness Synergy in Multicomponent‐Alloy Bonded Hardmetal

open access: yesRare Metals, Volume 45, Issue 5, May 2026.
ABSTRACT The inherent brittleness of hardmetals stems from the rigid covalent bond in the ceramic matrix and the sharp ceramic/metal interface, which restricts the nucleation and motion of dislocations. In this study, a novel strategy is proposed to activate significant dislocation behaviors in the WC matrix by employing a non‐equiatomic CoNiFeCr ...
Cheng Qian   +9 more
wiley   +1 more source

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