共查询到18条相似文献，搜索用时 812 毫秒
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通过构造含有复奇异指数的新应力函数,利用复合材料断裂复变方法对正交异性双材料界面裂纹应力奇异性进行了研究.通过求解一类偏微分方程组的边值问题,推出了正交异性双材料界面裂纹尖端应力具有λ=-1/2的常数奇异性,λ=-1/2+ε的非常数奇异性,λ=-1/2+iε的常数振荡奇异性和λ=-1/2+c+iε的非常数振荡奇异性,并建立了四种奇异性下正交异性双材料Ⅱ型中心穿透界面裂纹尖端的应力强度因子的计算公式以及应力场和位移场的解析解. 相似文献
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张彩凤 《湖南科技学院学报》2013,(8):9-12
比较讨论了两种求解I型裂纹的断裂因子的方法。第一种是通过在ANSYS软件建立实验模型,计算出应力强度因子;第二种是从J积分角度推导出应力强度因子公式,并使用MATLAB实现该计算,从而计算出应力强度因子。经过验证,得知有限元分析方法是可靠的。 相似文献
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由于裂纹尖端的奇异性,应用解析法求解复杂裂纹周边的位移场和应变应力场几乎不可行,然而可以采用数值法,借助ANSYS软件,对裂纹前缘、边缘的位移场和应变应力场进行模拟,模拟结果与断裂力学理论分析几乎一致. 相似文献
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利用大型有限元软件ANSYS/LS-DYNA的模拟功能,对轧辊的裂纹尖端开裂模式进行了模拟分析。在将裂纹尖端区域细化的基础上,得出含表面裂纹的热轧工作辊两个裂纹尖端的开裂模式是不同的,并且随着轧制深入以及裂纹扩展规律的影响,出现了裂纹尖端局部塑性区以及材料局部的卸载情况,使应力强度因子K以及J积分之间不再满足在线弹性过程中的换算关系形式。 相似文献
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根据珩磨加工特性和脆性陶瓷材料力学性能,应用断裂力学理论,分析加工表面裂纹尖端的应力强度因子及应力状态．珩磨附加拉应力增大陶瓷材料加工表面裂纹尖端的应力强度因子,降低陶瓷材料的临界磨削力,使陶瓷材料的去除容易进行．研究表明,珩磨可作为脆性陶瓷材料的一种高效加工方式． 相似文献
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《实验室研究与探索》2016,(5):123-126
提出了基于有限元分析的输电铁塔应力计算方法,并开发了输电铁塔实时应力计算系统。采用桁梁混合模型对输电铁塔进行建模,对铁塔结构进行离散化,以节点位移阵列作为未知量,与整体刚度矩阵,载荷阵列组成矩阵方程,采用置1法消除整体刚度矩阵的奇异性,运用高斯消元法求解节点位移矩阵,根据弹性力学中应力与位移的关系,给出各节点应力,最终求出铁塔受力情况。通过自主开发的输电铁塔实时应力计算系统反演了铁塔的倒塔事故。分析结果表明,该系统具有较高的计算精度,可用于输电铁塔实时应力计算。 相似文献
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赵连华 《常熟理工学院学报》2007,21(2):31-33
裂纹的应力应变状态对结构的断裂影响很大,是钢结构断裂分析和设计中研究的重点。由于一般构件的几何形状和荷载状态复杂,难于对裂纹尖端的应力应变状态得到理论解。本文利用ANSYS软件对受拉平板裂纹尖端三维应力状态进行了有限元分析,获得了钢结构裂纹尖端的应力分布规律。 相似文献
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The stress intensity factor (SIF) is a critical parameter associated with the fracture behaviour of materials. In this paper, we select the displacement function around a crack tip as the shape function of the digital image correlation (DIC), which makes it possible to directly calculate the SIF by the correlation scheme. Moreover, we use a non-rectangular subset, which can reduce the influence of plastic deformation and crack width on the DIC measurement accuracy. We measured the SIF of a mode I crack in a super-hard aluminium alloy specimen to verify the performance of the proposed method. Our experimental results show that a DIC with a specific shape function can be used to accurately and efficiently calculate the SIF. Furthermore, we also present a practical application of our proposed method for determining the SIF, crack propagation angle and crack tip displacement. 相似文献
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Theresistanceofapipelinesteeltohydrogensulfidestresscorrosioncracking (SCC)andhydrogen inducedcrack ing (HIC)isveryimportantforsteeltobeusedinsouroil/gasapplications.ElongatedMnSinclusionsarethemostsus ceptiblesitesforHICinitiation[1] ashydrogenatomscaneasi lyaccumulateattheinterfacebetweenthesteelmatrixandnon metallicinclusions.ThesegregationofsuchelementsasP ,Mn ,Cinthesteelenhancestheformationofhardbandsoncooling[2 ] .Theexistenceofthebandingstructurenotonlydecreasestheresistanceofthe… 相似文献
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ALSHOAIBI Abdulnaser M HADI M.S.A ARIFFIN A.K. 《浙江大学学报(A卷英文版)》2007,8(2):228-236
INTRODUCTION The finite element method (FEM) has proved to be very well suited for the study of fracture mechanics. Nevertheless, modelling the propagation of a crack through a finite element mesh turns out to be difficult because of the modification of the mesh topology. Use of crack propagation laws based on stress inten-sity factor range is the most successful engineering application of fracture mechanics. The stress intensity factors are a very important parameter in fracture analys… 相似文献
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ALSHOAIBI Abdulnaser M. ARIFFIN Ahmad Kamal 《浙江大学学报(A卷英文版)》2006,7(8):1336-1342
INTRODUCTION The finite element method (FEM) has been widely employed for solving linear elastic and elas-tic-plastic fracture problems. The evaluation of stress intensity factors in 2D geometries by FEM is a tech-nique widely used for non-standard crack configura-tions. Basically, there are two groups of estimation methods, those based on field extrapolation near the crack tip (Chan et al., 1970; Shih et al., 1976) and those using the energy release when the crack propagates. However… 相似文献
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XU Jing-jing WU Yi-min School of Electromechanical Engineering Automation Shanghai University Shanghai China 《上海大学学报(英文版)》2000,(Z1)
l lgtroductionIt is well known that the safety of pipeline systemsfor transpofting oil or gas is very important in the oil orgas industry, and it will be a catastTophe if an accidentoccurs. Howevef, there are a lot of methods for ensuringthe safety of such pipeline systems, for instance,TopRAM program['] (TransCanada Pipeline RiskAssessment Model), IAP program['] (The integrityAssessment Program), In-line inspection tools for crackdetection in gas and liquid pipeline['l etc. The safety … 相似文献
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Three-way pipes, T and Y pipes, are very important connecting components in pipeline systems, their strength are related to the
safety of pipelines. In the case that crack is not detected in the three-way pipe, ANSYS finite element program version 5.6 is applied to study
the stress distribution of the three-way pipe and to obtain the optimum fillet radius in the crotch region of the two pipes. The reasonable
intersection angle φ of the two pipes is also obtained. In the case that a surface crack is detected in the three-way pipe, the maximum stress
intensity factor (SIF) near the front of the surface crack is studied. 相似文献
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An adaptive mesh finite element model has been developed to predict the crack propagation direction as well as to calculate the stress intensity factors （SIFs）, under linear-elastic assumption for mixed mode loading application. The finite element mesh is generated using the advancing front method. In order to suit the requirements of the fracture analysis, the generation of the background mesh and the construction of singular elements have been added to the developed program. The adaptive remeshing process is carried out based on the posteriori stress error norm scheme to obtain an optimal mesh. Previous works of the authors have proposed techniques for adaptive mesh generation of 2D cracked models. Facilitated by the singular elements, the displacement extrapolation technique is employed to calculate the SIK The fracture is modeled by the splitting node approach and the trajectory follows the successive linear extensions of each crack increment. The SlFs values for two different case studies were estimated and validated by direct comparisons with other researchers work. 相似文献