弹性力学中混合变量的能量原理

建立了弹性力学中混合变量的虚功原理和虚余功原理,混合变量的最小势能原理和最小余能原理,混合变量最小势能的广义原理和最小余能的广义原理。同时,应用混合变量的最小势能原理于计算一复杂边界条件矩形板的弯曲。     

弹性力学中混合变量的极值变分原理

本文建立了弹性力学空间问题混合变量的最小势能原理和最小余能原理，并根据该最小势能原理给出了弯曲薄板混合变量的最小势能原理。应用该势能原理计算了一复杂边界条件矩形板的弯曲。     

声场的变分原理及有限元分析

给出了由声场的微分方程及边界条件导出的变分原理、广义变分原理以及由变分原理导出的有限元公式．通过对三个有代表意义的一维声场试验数据的比较分析，验证了上述变分原理及有限元公式的正确性．     

损伤粘弹性梁-柱的广义变分原理

从损伤的粘弹性材料的卷积型本构关系出发,建立了在小变形下损伤粘弹性梁-柱的控制方程,提出了以卷积形式表示的损伤粘弹性梁-柱弯曲问题的泛函,并给出了损伤粘弹性梁-柱的广义变分原理.应用这个广义变分原理,可分别给出梁-柱位移和损伤满足的基本方程,以及相应的初始条件和边界条件.     

广义混隐变分不等式解的存在性及算法

采用辅助变分原理技巧，证明了Hilbert空间内一类新的广义混隐变分不等式解的存在性，给出一个新的迭代算法．并讨论其收敛分析。我们的结果是近期献中相应结果的改进和推广。     

基于微分变分原理研究相空间中非完整系统的守恒律

为了进一步寻求动力学系统的守恒律,文章基于微分变分原理研究相空间中非完整力学系统的守恒律.首先从非保守系统的Hamilton原理出发,建立了相空间中非完整非保守系统的微分变分原理;其次,通过引进广义变分,给出了此微分变分原理在无限小变换下的不变性条件;最后,导出了相空间中非完整非保守力学系统的守恒律.文末举例说明结果的应用.     

非时间步参数时间有限元法

本文基于位移型Gurtin变分原理,对时间域进行离散时,采用具有非时间步参数的话值函数逼近广义节点位移,给出了一种新的计算弹性动力学初值问题的非时间步参数时间有限元法这是一种无条件稳定的计算格式算例表明,本文方法具有计算方法简便、实用以及精度较高的特点     

非线性混合似变分不等式解的存在性

本文介绍了自反Banach空间中一类非线性混合似变分不等式，利用极大极小不等式和辅助变分原理技术，给出了这类非线性混合似变分不等式解的存在性与唯一性的新证法。     

基于位移型Gurtin变分原理的非时间步参数时间有限元法

本文基于位移型Gurtin变分原理,对时间域进行离散时,采用具有非时间步参数的插值函数逼近广义节点位移,给出了一种新的计算弹性动力学初值问题的非时间步参数时间有限元法,这是一种无条件稳定的计算格式,通过算例,可知本文方法具有计算方法简便、实用和精度较高的特点。     

变分原理中的试探变分函数

变分原理在《结构化学》获《物质结构》中是很重要的内容，但在部分教材中介绍的不够完整。本文用实例说明选择试探变分函数不仅要符合品优条件，还要与所考虑体系有相同的边界条件。     

Equivalent Theorem of Hellinger-Reissner and Hu-Washizu Variational Principles

lintroductionIn1954,byso-calledtry-and-el.l.ormethodHull]deducedtheHu-Washizupl'inciple,whichplaysan.importantroleinthehistoryofvariation.In1964,ChienlZIsystematicallydiscussedtheLagrangemultipliermethod.Withthemethod,hesuccessfullydeducedHu-Washizuprinci…     

Equivalent theorem of Hellinger-Reissner and Hu-Washizu variational principles

The paper has proved that Hellinger-Reissner and Hu-Washizu variational principles are but equivalent principles in elasticity by following three ways: 1) Lagrange multiplier method. The paper points out that only a new independent variable can be introduced when one constraint equation has been eliminated by one Lagrange multiplier, which must be expressed as a function of the original variable(s) and/or the new introduced variable after identification. In using Lagrange multiplier method to deduce Hu-Washizu principle from the minimum potential energy principle, which has only one kind of independent variable namely displacement, by eliminating the constraint equations of stress-displacement relations, one can only obtain a principle with two kinds of variables namely displacement and stress; 2) involutory transformation, with such method Hu-Washizu variational principle can be deduce directly from the Hellinger-Reissner variational principle under the same variational constraints of stress-strain relation, and vice verse; 3)semi-inverse method, by which both of the above variational principles can be deduced from the minimum potential energy principle with the same variational constraints. So the three kinds of variational functions in Hu-Washizu variational principle are not independent to each other, the stress-strain relationships are still its constraint conditions.     

广义测不准关系对无限深势阱问题的影响

考虑了广义测不准原理,并重新计算无限深势阱问题,得到能量本征值。结果表明,此时的能量本征值除了包含通常的En=h2π2n2蛐2ma2以外,还包含能量修正项。而且能量本征值修正项只与参数α有关,与其它的参数没有关系。     

浅谈变频器的工作原理及其应用

通用变频器特点突出、性能优良,应用十分广泛.本文对变频器工作原理控制方式、变频器的应用、变频器起动加速能力的校验,以及如何合理选用进行了较为详细的阐述.     

Exact Computation of Parallel Robot''''s Generalized Inertia Matrix

According to the definition of the new hypothetical states which have obvious physical sig-nificance and are termed as no-gravity static and accelerated states, a method for exact computa-tion of the parallel robot's generalized inertia matrix is presented. Based on the matrix theory, the generalized inertia matrix of the parallel robot can be computed on the assumption that the robot is in these new hypothetical states respectively. The approach is demonstrated by the Delta robot as an example. Based on the principle of the virtual work, the inverse dynamics model of the robot is formulized after the kinematics analysis. Finally, a numerical example is given and the element dis-tribution of the Delta robot's inertia matrix in the workspace is studied. The method has computational advantage of numerical accuracy for the Delta robot and can be parallelized easily.     

基于能量变分的短肢剪力墙力学性能研究

考虑了短肢剪力墙翼板的剪力滞后效应,构造了新的截面位移模式和剪滞翘曲位移函数,基于能量变分原理和刚度法导出了短肢剪力墙考虑剪滞效应和剪切变形的结构分析平面单元刚度矩阵,从而得到简单易行的短肢剪力墙的力学性能分析方法,通过算例分析结果证实本方法是可行的。