文 颖, 曾庆元. 平稳运动稳定性分析的位移变分法[J]. 工程力学, 2011, 28(4): 1-006,.
引用本文: 文 颖, 曾庆元. 平稳运动稳定性分析的位移变分法[J]. 工程力学, 2011, 28(4): 1-006,.
WEN Ying, ZENG Qing-yuan. STABILITY ANALYSIS OF STEADY MOTION USING THE DISPLACEMENT-BASED VARIATIONAL METHOD[J]. Engineering Mechanics, 2011, 28(4): 1-006,.
Citation: WEN Ying, ZENG Qing-yuan. STABILITY ANALYSIS OF STEADY MOTION USING THE DISPLACEMENT-BASED VARIATIONAL METHOD[J]. Engineering Mechanics, 2011, 28(4): 1-006,.

平稳运动稳定性分析的位移变分法

STABILITY ANALYSIS OF STEADY MOTION USING THE DISPLACEMENT-BASED VARIATIONAL METHOD

  • 摘要: 该文论述系统平衡状态受到位移干扰(即位移变分)时,产生抗力增量与荷载增量,当前者大于后者时,平衡状态稳定;小于时,则不稳定,得出平衡状态稳定性的力素增量判别准则。而两种增量的代数和即系统平衡方程位移变分与其系数之积,当系数大于零时,平衡状态稳定;小于零时,不稳定,得出位移变分系数的判别准则,简称为位移变分法。按照D’Alembert原理,可将动力学问题转化为静力学问题来处理,此种位移变分法可用于运动稳定性的分析。该文7个例子的计算结果均与经典理论解相同,并有经典解得不出的若干结果。

     

    Abstract: A general criterion for checking the stability of the equilibrium state of a system in steady motion is presented. Such a criterion requires that: when being disturbed a change in a system the resistance will certainly occur according to the level of external excitations, the system will remain stable if the generated resistances surpass the effect of applied disturbance. Otherwise, the system becomes unstable. This procedure can be more appropriately termed a displacement-based variational method, as the small displacement changes resulting from the process of disturbance is employed to measure the resistance offered by the system. Based on D’Alembert’s principle, where dynamic problems can be treated in a static way, the proposed method is applicable to the problems of dynamic stability as well. Results of seven illustrative problems are essentially identical to classical solutions, which serves as a strong basis enabling the application of the present method to the problems of stability of steady motion.

     

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