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本文介绍了文献[2]的一个脚注,指出 Tresca 屈服条件(2)或(3)式的不正确性,并说明了理由. 相似文献
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对Mises屈服准则的一种新解释 总被引:1,自引:0,他引:1
对Mises屈服准则的一种新解释王庆明,朱国辉,程耀东(浙江大学动力工程及工程热物理博士后科研流动站,杭州310027)长期以来,人们在研究Mises屈服准则时都没有与最大剪应力T_(max)相联系,本文从一个新的角度分析Mises准则,揭示T_(m... 相似文献
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构造了一种在π平面上为椭圆的后续屈服函数,将该屈服函数、“Tresca”及“Misses型”后继屈服函数分别应用于干涉孔及冷胀孔问题的弹塑性有限元分析,并对这三种屈服函数在弹塑性有限元中的应用进行了评估。本文三种屈服函数在弹塑性问题中的应用评估对更有效地解决工程中的弹塑性问题有着实际的应用价值。 相似文献
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含蜡原油屈服值是用于计算停输管线再启动压力的重要流变参数。作者建立了一套小型微机数据采集的模拟装置用于测定含蜡原油在给定温度条件下的屈服值,通过模拟热输管线实际工况,针对两种典型胶凝原油,分析了胶凝在管线中原油的屈服机理,首次提出了油中空隙对胶凝强度的影响关系。为长输原油管道的间歇输送工艺及停输再启动技术提供了理论依据。 相似文献
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在材料力学教学实验中如何验证第四屈服准则肖隆秀(北京航空航天大学,北京100083)文献[1]提出了“屈服准则验证实验”方法,则将屈服准则表达式统一写为σ2+ατ2=σs,(第三强度理论α=4,第四强度理论α=3),用圆截面试件先拉到屈服,但并不使屈... 相似文献
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基于Hopkinson压杆的动态压剪复合加载实验研究 总被引:2,自引:0,他引:2
提出了一种可用于研究压剪复合加载下, 材料动态力学性能的实验装置, 该装置基于Hopkinson压杆, 通过添加一个带倾斜端面的垫块, 实现压剪复合加载.分析了该实验装置的基本数据处理方法, 并利用有限元分析验证了此分析方法的可行性;然后利用该装置对常规金属材料进行了相同冲击速度, 不同倾斜角度(0$^\circ$,30$^\circ$, 45$^\circ$)下的一系列实验. 实验结果表明, 该装置能实现压剪复合加载, 并且能得到材料的动态屈服面, 为研究材料在复杂应力状态下的动态力学性能提供了新的实验方法. 相似文献
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基于Hertz 理论圆柱和平面之间的滑动接触分析 总被引:1,自引:1,他引:1
当圆柱与平面之间产生摩擦滑动接触时,基于Hertz理论,推导了平面内应力分量的计算公式,分析了应力的分布,描述了应力分布的特点.在接触表面上,存在最大拉应力和最大压应力;最大拉应力出现在拖动边的边缘,而最大压应力发生在导向边的区域.因此,如果接触平面因拉或压应力引起失效,首先会出现在接触表面;第一型裂纹的产生及扩展首先会发生在拖动边的边缘.剪应力,主剪应力及Von-M ises等效应力(当摩擦系数较小时)的最大值均会出现在接触体内,存在于导向边.因此,塑性滑移开始首先会发生在接触体内,然后,才扩展到接触表面.这些结论为工程应用研究提供了依据. 相似文献
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对材料力学中梁的弯曲应力公式增加一修正项,以反映短梁弯剪翘曲变形对应力分布的影响。提出一种根据短梁横截面边界形状及艾瑞应力函数求解应力修正项的方法,应用弹性力学空间问题的一般理论,通过应力平衡方程、应变相容方程及应力边界条件,建立了关于任意截面短梁的应力修正项及剪应力的基本方程。在所建立的基本方程基础上,导出了矩形截面和圆形截面短梁修正应力的具体计算公式,该修正应力与均布荷载大小及弹性模量与剪切模量之比均成正比,但与截面惯性矩成反比。数值算例表明,本文方法计算的应力与通用有限元软件ANSYS计算的结果吻合良好,从而验证了本文方法及其基本公式的正确性。 相似文献
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Magneto-elastic stress in a thin infinite plate with an elliptical hole under uniform magnetic field
Norio Hasebe 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(6):745-764
Two-dimensional magnetic field and magneto-elastic stress solutions are presented for a magnetic material of a thin infinite
plate with an elliptical hole under uniform magnetic field. The linear constitutive equation is used for the magnetic field
and the stress analyses. The magneto-elastic stress is analyzed using Maxwell stress since only Maxwell stress is caused as
a body force according to the electro magneto theory. Except the approximation of the plane stress state in which the plate
is thin, no further assumption is made for the stress analysis, though Maxwell stress components are expressed by nonlinear
terms. The rigorous boundary condition expressed by Maxwell stress is completely satisfied without any linear assumptions
on the boundary. First, magnetic field and stress for soft ferromagnetic material is analyzed and then those for paramagnetic
and diamagnetic materials are analyzed. It is stated that the stress components are the same expressions for those materials
and the difference is only the magnitude of the permeability, though the magnetic fields are different each other in the plates.
If the analysis of magnetic field of paramagnetic materials is easier than that of soft ferromagnetic material, the stress
analysis may be carried out using the magnetic field for paramagnetic material. Shear deflection as well as stress in the
direction of the plate thickness arises and the solutions are also obtained. Figures of the magnetic field and stress distribution
are shown. Stress intensity factors are also derived. 相似文献
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封闭应力对岩石力学特性的影响不容忽视。从陈宗基提出岩石的封闭应力定义以来,研究的学者较少。本文从前人对封闭应力的定义出发,结合岩石力学发展现状,对封闭应力概念进行了拓展,提出了新的定义。将岩石力学研究中符合封闭应力定义的应力形式进行了归纳和分类,总结了各类封闭应力的变化规律及其计算公式,讨论了封闭应力与地下工程开挖之间存在的关联性及其影响的表达形式。本文对于推动封闭应力的深入研究具有积极意义,将为解释深部岩石力学特殊现象提供新的途径。 相似文献
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Hideo Koguchi Joviano Antonio da Costa 《International Journal of Solids and Structures》2010,47(22-23):3131-3140
The stress singularity that occurs at a vertex in a joint with a slanted side surface is investigated. The orders of stress singularity at a vertex and at a point on stress singularity lines for various material properties are determined using eigenanalysis. The stress distribution on an interface and the intensity of stress singularity at the vertex are investigated using BEM. It is shown that the order of stress singularity at the vertex in the joints can be reduced by slanting a side surface so as to decrease the angle between the interface and the side surface. The results of BEM analysis reveal that the distribution of stress on the interface is influenced by the slanted side surface. Finally, the 3D intensities of the singularity for stress components which are continuous at the interface are newly defined and determined for various material combinations. 相似文献
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Conditions of equilibrium of forces are formulated for a force system in a continuous body which consists of a bulk stress
and a stress concentrated on a curve. The system of forces is interpreted as a tensor valued measure and the equilibrium of
forces is interpreted in a weak sense. The divergence theorem is proved for bulk stress fields with the corresponding singularity.
Examples of such stress fields are given.
相似文献
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J. Srinivas J. V. Ramana Murthy 《Journal of Applied Mechanics and Technical Physics》2016,57(6):997-1005
An analytical study of the entropy generation rate and heat transfer in a flow of immiscible couple stress fluids between two horizontal parallel plates under a constant pressure gradient is performed. Both plates are kept at different and constant temperatures higher than that of the fluid. The Stokes couple stress flow model is employed. The classical no-slip condition is prescribed at the plates, and continuity of the velocity, rotation, couple stress, shear stress, temperature, and heat flux is imposed at the interfaces. The velocity and temperature distributions are found analytically, and they are used to compute the entropy generation number and Bejan number. The effects of the couple stress parameter and Reynolds number on the velocity, temperature, entropy generation number, and Bejan number are investigated. It is observed that the friction near the plates in couple stress fluids decreases as the couple stress increases. 相似文献
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Yu. N. Shevchenko R. G. Terekhov N. N. Tormakhov 《International Applied Mechanics》2007,43(6):621-630
Constitutive equations relating the components of the stress tensor in a Eulerian coordinate system and the linear components
of the finite-strain tensor are derived. These stress and strain measures are energy-consistent. It is assumed that the stress
deviator is coaxial with the plastic-strain differential deviator and that the first invariants of the stress and strain tensors
are in a nonlinear relationship. In the case of combined elastoplastic deformation of elements of the body, this relationship,
as well as the relationship between the second invariants of the stress and strain deviators, is determined from fundamental
tests on a tubular specimen subjected to proportional loading at several values of stress mode angle (the third invariant
of the stress deviator). Methods to individualize these relationships are proposed. The initial assumptions are experimentally
validated. The constitutive equations derived underlie an algorithm for solving boundary-value problems
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 43–55, June 2007. 相似文献