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virtual displacement [work] 【物理學】虛位移[功]。

virtual height

Based upon virtual displacement method and the updated - lagrangian approach , stiffness matrices for two - dimensional elastic - plastic beam model in large displacement were proposed , in the derivation of which transverse stress was included because it was believed that part of the 2nd order effects of various stresses , which are in equilibrium with each other and with the external loads , will counteract each other and neglecting either part would possibly lead to incorrect results 利用虛位移原理和更新的拉格朗日方法,導出了大位移彈塑性梁單元剛度矩陣的顯式表達式,在剛度矩陣推導中引入了截面內非線性剪應力和橫向應力的影響,剛度矩陣通過了剛體檢驗。之所以要引入橫向應力的影響,是因為本文認為,保持平衡所需的所有應力,它們各自的二階效應會相互抵消,因此忽略其中的任何一項都可能導致不正確的結果。

Moreover , popularizing such system is expected . the following works have been fulfilled within this thesis : first of all , based on the general principle of virtual displacement of nonlinear continuum mechanics , the geometric and material stiffness matrices is presented , several examples show that both of them can give out accurate result 本論文主要完成了以下工作:首先,根據連續介質力學理論構造出的交錯桁架結構空間單元的幾何剛度矩陣和彈塑性剛度矩陣,算例分析表明這些矩陣能準確地計算出結構的空間二階效應和空間單元彈塑性桿端力增量,計算結果具有良好的精度。

The rational spectrums of all kinds of virtual displacement definitions and commutativity of d , ? operations are given and testified in this paper . the research methods of intrinsical linear nonholonomic dynamics are similar to those of holonomic dynamics . the rationality and equivalence of chetaev model and vacco model in the intrinsical linear nonholonomic system are testified from the mathematic and mechanical aspects 本文研究了非完整動力學中使不定性問題確定化的交換關系和將非線性問題線性化的虛位移定義,首次證明并給出了在非完系統中各種虛位移定義與交換關系的合理適用范圍,指出完整動力學與本質線性非完整動力學在研究方法上具有相同性。

They are studied that the nonlinear problem and un - determinate problem of virtual displacement in nonholonomic system in the second chapter . in chapter 3 , they are studied that chetaev model and vacco model in nonholonomic system . a unified form of hamilton principle in intrinsical linear nonholonomic system is studied in chapter 4 第一章對非完整動力學研究的有關現狀進行了綜合評述;第二章研究了非完整系統虛位移關系的不定性問題與非線性問題;第三章比較研究了一般非完整系統的chetaev模型和vacco模型;第四章研究了本質線性非完整系統的hamilton原理;第五章給出了本文的結論與有關研究的展望。

This dissertation studies the problem of dynamics modeling , dynamical response , and distribution of moving mass for a re - entry vehicle ( mmcrv ) under the background of national natural science fund project “ precision control and guidance for moving mass control of a re - entry vehicle based on the virtual displacement concept ” 本論文以國家自然科學基金項目“基于虛位移概念的變質心再入飛行器精確制導問題研究”為背景,研究基于變質心控制的再入體動力學建模、動力學響應和落點分布等問題。

Principle of virtual displacement 虛位移原理