Results 11 to 20 of about 391,064 (148)

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  

疲劳荷载特性对8.8级M24高强度螺栓疲劳裂纹扩展机理影响探析

open access: yesJianzhu Gangjiegou Jinzhan, 2023
为研究常幅疲劳荷载特性对高强度螺栓疲劳裂纹扩展的影响,针对钢结构端板连接用8.8级M24高强度螺栓在不同应力比/应力幅作用下常幅疲劳试验所得到的24个试件断口形貌进行定量分析,并采用ABAQUS软件数值模拟高强度螺栓应力集中情况,探讨含初始裂纹高强度螺栓裂纹尖端应力强度因子与荷载特性、预制裂纹形状之间的关系。结果表明:在轴向受拉疲劳荷载作用下,螺母与螺栓啮合第1圈螺纹处为疲劳断裂最不利位置;试件断口稳定扩展区面积与应力比/应力幅呈负相关,快速扩展区面积与应力比/应力幅呈正相关 ...
樊丽轩   +4 more
doaj  

基于断裂力学的GH3535合金蠕变裂纹扩展模拟和寿命评估

open access: yesHe jishu
在第四代先进反应堆钍基熔盐堆(Thorium Molten Salt Reactor,TMSR)中,高温含缺陷构件的寿命预测是结构完整性评估的重要环节。在该研究中,首先基于随时间变化的蠕变断裂力学,采用有限元分析(Finite Element Analysis,FEA)软件的围线积分方法计算蠕变断裂参量C*,结合Python语言编写的自动化分析程序,预测了GH3535合金紧凑拉伸试样C(T)的蠕变裂纹扩展(Creep Crack Propagation,CCP ...
王 雯, 王 晓艳, 李 志军
doaj   +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

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  

A Review on Cracking in Laser Additive Manufacturing of Nickel‐Based Superalloys: Types, Formation Mechanisms, and Suppression Strategies

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Nickel‐based superalloys (Ni‐based superalloys) have attracted extensive attention in laser additive manufacturing (LAM) due to their capability to directly fabricate complex and high‐performance structural components. However, the rapid melting and solidification inherent to LAM result in intense thermal cycling, which induces high residual ...
Tianxiang Lin   +9 more
wiley   +1 more source

Damage tolerance analysis of wading structures of amphibious aircraft based on Franc3D

open access: yesXibei Gongye Daxue Xuebao, 2022
Aiming at the combined action effect of the corrosive environment of amphibious aircraft wading structures and random loads including water surface take-off and landing impact, based on the standard load spectrum TWIST of transport aircraft, considering ...
HE Erming   +4 more
doaj   +1 more source

Cluster‐Driven Strengthening and Oxide Stripes‐Induced Embrittlement in Internally Oxidized AgMg Alloys

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Internal oxidation has been identified as an effective method for enhancing the strength of AgMg alloys. However, the concurrent occurrence of embrittlement remains inadequately understood, thus limiting their broader application. This study investigates the oxidation behavior of AgMg alloys with Mg concentrations ranging from 1 at% to 7 at ...
Hai‐Cheng Zhu   +12 more
wiley   +1 more source

On the Damage Tolerance of Diffusion Bonded Titanium–Aluminum Phase Biomimetic Composites

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT The biomimetic design principles of natural structures involve the strategic integration of stiff and compliant phases to synergistically enhance strength and toughness. Its evolutionary refined natural armor, characterized by a specialized microarchitecture, enables superior damage tolerance.
Shuai Tong   +10 more
wiley   +1 more source

氧化锌非线性电阻片隐性开裂分析

open access: yesDianci bileiqi, 2022
针对氧化锌非线性电阻片制造过程中隐性开裂的问题,采用金相显微镜等方法,对开裂断面的显微结构形貌、受力方式进行分析验证,探究了塑性开裂和脆性开裂两种隐性开裂的机理以及隐性开裂发生的时段。结果表明,氧化锌非线性电阻片发生隐性开裂的主要形式是在排结合剂之后发生的脆性开裂,这种开裂方式是在受力磕碰后,早期表现为非常隐蔽的微裂纹,后经高温烧结裂纹进一步扩展,最后受磨片剪切应力后开裂显现的一种失效模式。
张文刚   +5 more
doaj  

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