共查询到18条相似文献,搜索用时 140 毫秒
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为研究摩擦接触问题,本文建立了一个具有二类独立变量的二维弹塑性梁模型,由此提出了一个新的非线性二次互补性问题。其中的外部互补性条件定义了自由边界;而内部互补性条件则控制弹塑性分界面。文中证明了此二次互补问题等价于一非线性变分不等式,并导出了其对偶变分不等式。 相似文献
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本以Signorini接触问题为背景,讨论了变分不等式与边值问题的等价性,利用Green公式,基本解和基本解法向导数的性质,将区域型变分不等式化成等价的边界型变分不等式,并证明了边界变分不等式解的存在唯一性,为使用边界元方法数值求解提供理论依据。 相似文献
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摩擦约束弹性力学广义变分不等式解的存在性和唯一性 总被引:4,自引:0,他引:4
阐述了等价于摩擦约束弹性力学基本问题的广义变分不等式问题解的存在性和唯一性,进而提出广义变分不等式有限元近似及其离散解法。 相似文献
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为研究摩擦接触问题,本文建立了一个具有二类独立交量的二维弹塑性梁模型。由此提出了一个新的非线性二次互补性问题。其中的外部互补性条件定义了自由边界;而内部互补性条件则控制了弹塑性分界面。文中证明了此二次互补性问题等价于一非线性变分不等式,并导出了其对偶变分不等式。本文结果显示对偶问题较原问题有更多的优越性。应用于塑性极限分析理论中,文中最后证明了一个简单的下限定理。 相似文献
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建立了描述变形体和基础间接触问题的数学模型.接触是双面的,并采用非局部摩擦定理建模,支承列入计算.粘结场(bonding field)的变化用一个一阶的常微分方程来表示,材料特性用一个非线性粘弹性本构关系建模.导出了该力学问题的变分公式,当摩擦因数充分小时,证明了其弱解的存在性和唯一性.依赖于时间的变分不等式、微分方程和Banach不动点理论,是该证明依据的基础. 相似文献
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本文讨论带梯度障碍的抛物型变分不等式解的存在性、唯一性和正则性问题.通过证明一类带梯度障碍的问题的求解等价于解某个双边障碍的问题,并利用双边障碍问题解的存在性、唯一性和正则性,得到了带梯度障碍的问题的相应结果.这一方法将有助于对具有梯度约束的非线性以及完全非线性抛物型方程解的正则性的研究. 相似文献
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塑性全量理论的变分不等式模式及其无迭代解 总被引:1,自引:0,他引:1
变分不等式是解决一类带单侧约束的定常力学问题的有效数学工具.本文就弹塑性全量理论构造了等价的变分不等式模式,解除了弹塑性问题本构约束的不等式关系,比一般能量形式的描述更为简洁.它便于计算,具有可靠的数学依据,可以用二次规划法求解.计算时无需分级加载迭代,一步即可得收敛解. 相似文献
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一个第二类变分不等式的有限元逼近 总被引:1,自引:0,他引:1
本短文讨论下述第二类变分不等式(见 [2, 4])的有限元逼近及其误差分析:其中是平面凸多边形区域的的边界, 且而 . 诸如热量控制问题,流体通过半可透性壁的扩散问题以及简化库仑摩擦接触问题的正则化方法等均可归为上述变分不等式(1)(见[2,3]).在文[2]中给出了上述变分不等式的有限元逼近格式,作出了收敛性分析及误差估计.本文的目的是进一步用数值积分简化上述有限元逼近格式并改进原有的估计误差. 设Th是的拟一致三角形部分,Vh是对应的线性元空间,且使得vh=0在上.[2]中用数值积分代替其中 Mi… 相似文献
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We study the interior and exterior contact problems for hemitropic elastic solids. We treat the cases when the friction effects, described by Tresca friction (given friction model), are taken into consideration either on some part of the boundary of the body or on the whole boundary. We equivalently reduce these problems to a boundary variational inequality with the help of the Steklov–Poincaré type operator. Based on our boundary variational inequality approach we prove existence and uniqueness theorems for weak solutions. We prove that the solutions continuously depend on the data of the original problem and on the friction coefficient. For the interior problem, necessary and sufficient conditions of solvability are established when friction is taken into consideration on the whole boundary. 相似文献
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带摩擦的弹性接触问题广义变分不等原理的简化证明 总被引:4,自引:0,他引:4
在弹性摩擦接触问题中 ,从变分原理出发来研究接触问题 ,可以将摩擦力纳入问题的能量泛函 .为了得到摩擦约束弹性接触问题的能量泛函 ,日前大多是用拉格朗日乘子法 ,但拉格朗日方法用在变分不等问题中 ,要利用非线性泛函分析和凸分析来证明 ,证明复杂 .本文利用向量分析的工具及巧妙的变换 ,对带摩擦约束的弹性接触问题的广义变分不等原理进行了严格的证明 ,由于只用到向量分析 ,简化了证明 . 相似文献
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In this paper we examine an evolution problem which describes the dynamic bilateral contact of a viscoelastic body and a foundation.
The contact is modeled by a friction multivalued subdifferential boundary condition which incorporates the Coulomb law of
friction, the SJK model and the orthotropic friction law. The main result concerns the existence and uniqueness of weak solutions
to the hyperbolic variational inequality when the friction coefficient is sufficiently small. The proof is based on a surjectivity
result for multivalued operators and a fixed point argument.
Research supported in part by the State Committee for Scientific Research of the Republic of Poland (KBN) under Grants no.
2 P03A 003 25 and 4 T07A 027 26. 相似文献
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Marius Cocou Mathieu Schryve Michel Raous 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2010,94(3):721-743
The aim of this paper is to study an interaction law coupling recoverable adhesion, friction and unilateral contact between
two viscoelastic bodies of Kelvin–Voigt type. A dynamic contact problem with adhesion and nonlocal friction is considered
and its variational formulation is written as the coupling between an implicit variational inequality and a parabolic variational
inequality describing the evolution of the intensity of adhesion. The existence and approximation of variational solutions
are analysed, based on a penalty method, some abstract results and compactness properties. Finally, some numerical examples
are presented. 相似文献
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Marius Cocou Mathieu Schryve Michel Raous 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2010,61(4):721-743
The aim of this paper is to study an interaction law coupling recoverable adhesion, friction and unilateral contact between two viscoelastic bodies of Kelvin–Voigt type. A dynamic contact problem with adhesion and nonlocal friction is considered and its variational formulation is written as the coupling between an implicit variational inequality and a parabolic variational inequality describing the evolution of the intensity of adhesion. The existence and approximation of variational solutions are analysed, based on a penalty method, some abstract results and compactness properties. Finally, some numerical examples are presented. 相似文献
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We consider the variational free boundary problem describing the contact of an elastic plate with a thin elastic obstacle. The contact domain is unknown a priori and should be determined. The problem is described by a variational inequality for a fourth-order operator. The constraint on the displacement is given on a set of dimension less than that of the solution domain. We find the boundary conditions on the set of the possible contact and their exact statement. We justify the mixed statement of the problem and analyze the limit cases corresponding to the unbounded increase of the elasticity coefficients of the contacting bodies. 相似文献