Results 61 to 70 of about 1,293 (161)
Meso-macro analysis of microwave-assisted double-indenter impact on rock-like materials [PDF]
Given the constraints on explosives and in response to the national “dual carbon” strategic goals, a new method of microwave-assisted impact fragmentation of rock-like materials has broad prospects in hard-rock tunneling, concrete structure demolition ...
Akang LI +6 more
core +1 more source
Hydrogen embrittlement susceptibility of the X70 pipeline steel substrate and weld in simulated coal gas containing hydrogen environment [PDF]
, 2017 The diffusion and accumulation behaviour of hydrogen in X70 pipeline steel were investigated via hydrogen permeation test, hydrogen diffusion simulation, and hydrogen content test technology in a simulated coal gas environment (4 MPa total pressure, 0.2 ...
GUAN Hong-peng +6 more
core +1 more source
Dianci bileiqi, 2016 采用基于内聚力裂缝模型（CCM）的有限元分析方法,模拟支柱式绝缘子的不同结构界面的力学特性,仿真再现了绝缘子受弯矩外载下界面脱粘失效的过程,并研究了粘结界面力学性能对绝缘子整体承载力的影响。分析表明,粘结层开裂过程可分为界面承载、界面开裂和裂纹扩展3个阶段;水泥粘结剂与金属基座的粘结层开裂时间早、脱粘速度快是绝缘子结构的薄弱环节;界面刚度、断裂能、极限强度的增加均能有效提高绝缘子的结构承载力,但随着承载力增加,破坏模型由界面脱粘变为水泥粘结剂受拉破坏。
马艳枝, 张艳红, 刘占民
doaj
, 1994 通过对紧凑拉伸试样裂纹扩展实验的有限元仿真模拟以及对中心裂纹试样和三点弯曲试样的精细有限元计算和分析;证实了稳态扩展裂纹尖端附近环形区内应力场三参数J-k_2-Q表征的有效性。研究结果进一步表明:在扩展裂纹尖端附近的环形区域内;因试样几何类型的不同;存在着不同类型的双参数主导区。对紧凑拉伸试样和弯曲裂纹试样;在裂关附近环形区内存在着J-k_2主导区;而对中心裂纹试样;在裂尖附近环形区内则存在着J-Q主导区。在一般情况下;应由J-k_2 ...
王自强, 魏悦广
core
Mechanical properties and energy evolution mechanism of coal prone to ejection [PDF]
In this paper, true triaxial loading and unloading tests under different principal stress conditions were conducted to study the mechanical properties, failure characteristics, and energy evolution laws of coal bodies that are prone to ejection under ...
Wentao XU, Yunhai CHENG
core +1 more source
Q355B钢对接接头气孔缺陷对疲劳寿命影响的试验研究与数值模拟
Jianzhu Gangjiegou Jinzhan焊接过程常伴随着气孔、夹渣、咬边等缺陷的产生，这些缺陷在疲劳荷载作用下容易导致疲劳裂纹的产生和扩展。使用有限元软件ABAQUS结合断裂力学分析软件Franc3D，建立含气孔缺陷的对接接头有限元模型，并在应力集中最大值处植入裂纹，依据断裂力学M积分对含裂纹的模型进行数值模拟，得到了不同初始裂纹长度和焊缝宽度下裂纹尖端的应力强度因子。分析结果显示，裂纹尖端的应力强度因子对初始裂纹长度变化敏感，随长度增加而增加，而裂纹两端的应力强度因子则呈相反趋势；增加焊缝宽度可以显著降低应力强度因子，随着焊缝宽度的增加 ...
熊海江 +4 more
doaj +2 more sources
Jianzhu Gangjiegou Jinzhan, 2018 以含椭圆形表面裂纹的三维平板为例,比较了J积分法、相互作用积分法、1/4结点位移法和扩展有限元法(XFEM)等方法计算应力强度因子(SIF)的特点。首先介绍了这4种方法的原理,将它们计算的平板表面裂纹SIF与国际认可的Newman-Raju公式计算值进行对比,均与公式计算值吻合较好,但XFEM计算的SIF沿裂纹前缘呈现出较小的振荡。然后,分析了这些方法计算的SIF对网格尺寸的敏感性,发现J积分法和相互作用积分法计算的SIF非常稳健,对网格尺寸不敏感,而其余方法对网格尺寸均有一定程度的敏感性。另外 ...
肖顺, 童乐为
doaj
Computer Simulating of Through or part-through Fatigue Crack Propagation [PDF]
, 1996 根据疲劳裂纹扩展的规律，对等幅和变幅谱载下CCT及PS（T）试件的疲劳裂纹扩展进行了计算机模拟。其结果经疲劳试验考评，误差在40%以内，能满足疲劳分析的要求。According to characters of Fatigue crack propagation,we imitated the tests of CCT and PS(T) by computer under constant amplitude and varied amplitude spectrum loading.The ...
宋建华, 成建国, 黄振仁
core
Control of two-phase pitch precursor and microstructure of cross-section of carbon fibers [PDF]
, 2017 为给高性能碳纤维的结构设计提供理论参考,利用各向同性煤沥青(IPc)与中间相沥青形成二元不相容共混物的相分离结构,并利用筛网装置改变共混沥青的熔; 体流动状态,研究共混两相沥青的相结构对最终碳纤维结构的影响。结果表明:在共混前驱体中,掺杂的15%; IPc不足以抑制劈裂的形成;而使用15层筛网纺丝装置,促进微畴沿径向折叠排列,抑制了轴向劈裂的出现;进一步提高熔体受剪切程度,各向同性相形成贯穿; 的条带结构,纤维截面重新出现劈裂结构。30%的各向同性相抵抗了碳纤维中的裂纹扩展 ...
余木火, 刘安华, 姚艳波
core +1 more source
Parameter calibration and application of GTN damage model for girth weld in X80 pipeline [PDF]
Objective Numerical simulations represent an important approach to studying the damage evolution behaviors of oil and gas pipelines constructed using high-grade steel.
Haitao WANG +6 more
core +1 more source