共查询到20条相似文献,搜索用时 31 毫秒
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闭环柔性多体系统的多点撞击问题 总被引:3,自引:0,他引:3
用于结构方法和单向递推组集方法研究闭环的柔性多体系统的多点撞击问题。在撞击过程中,在切割铰中增加撞击铰,导出了以铰坐标和柔性体模态坐标为系统广义坐标的闭环柔性多体系统在撞击阶段的动力学方程。利用相对坐标下约束方程的Lagrange乘子和利用绝对坐标下约束方程的La-grange乘子相等的关系求出切割铰的约束力,即撞击力。提出了撞击铰的切换方法。计算了卫星太阳电池卫帆板展开锁定时帆板之间多个接触处撞 相似文献
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在大型复杂的结构设计过程中,子结构综合与修正方法由于其快速、动态、综合等特点越来越广泛地应用于现代结构设计之中,以完善子结构综合与修正方法知识参考、引起国内学者关注该技术研究为目的,阐述了振动子结构与系统之间的综合与修正方法。在子结构综合方法中,主要对比分析了模态缩减与综合、频域JETMUNDSEN、REN、机械阻抗导纳法综合法、频响函数奇异值分解降噪法、子系统转角自由度刚柔等效及转换方法的原理及应用,评述了上述方法的优点与不足,就尚未解决的问题作了进一步探讨;在子结构修正方法中,对比分析了多重参考基准修正法、目标函数动态修正法、参数型修正、神经网络型修正、灵敏度修正、频响函数修正等方法的应用,总结了模型修正方法中存在的一些问题。最后,提出了振动子结构综合及修正方法的研究趋势。 相似文献
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《Mechanism and Machine Theory》1984,19(3):307-317
A procedure is presented for determining critical running speeds of flexible mechanisms. In this procedure, the flexible links are represented by finite elements. Governing equation components, throughout a cycle, are represented by truncated Fourier series. By comparing harmonic terms, the problem of determining the critical running speeds for a physically undamped mechanism is reduced to that of an eigenvalue problem, and a discrete set of critical running speeds is found. A proposed method of determining stable and unstable regions of input speed operation for a flexible mechanism is also presented. 相似文献
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本文介绍了一种进行高速弹性机构满应力优化设计的方法。在进行迭代优化时,快速准确地求出迭代矩阵是提高计算效率的关键。给出了简便地求出雅可比迭代矩阵的方法,由于采用了精确的弹性机构的迭代矩阵,故该方法适合于许用应力较大的高速弹性机构满应力的优化设计。 相似文献
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General Model to Predict Power Flow Transmitted into Laminated Beam Bases in Flexible Isolation Systems 总被引:1,自引:0,他引:1
For estimating the vibration transmission accurately and performing vibration control efficiently in isolation systems, a novel general model is presented to predict the power flow transmitted into the complicate flexible bases of laminated beams. In the model, the laminated beam bases are simulated by the first-order shear deformation laminated plate theory, which is relatively simple and economic but accurate in predicting the vibration solutions of flexible isolation systems with laminated beam bases in comparison with classical laminated beam theories and higher order theories. On the basis of the presented model, substructure technique and variational principle are employed to obtain the governing equation of the isolation system and the power flow solution. Then, the vibration characteristics of the flexible isolation systems with laminated bases are investigated. Several numerical examples are given to show the validity and efficiency of the presented model. It is concluded that the presented model is the extension of the classical one and it can obtain more accurate power flow solutions. 相似文献
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提出了具有连接子结构的固定界面模态综合法。基于本方法编制了三个子结构的固定界面模态综合法程序。所结算例表明 ,该方法计算量小 ,精确度高 ,可用于复杂耦合系统的动态特性分析。 相似文献
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两层两环空间耦合链机构自由度分析原理 总被引:1,自引:0,他引:1
自由度分析是机构构型综合、运动学和动力学研究的基础。过去的几十年,国内外学者主要对空间并联机构自由度分析开展了研究。研究比空间并联机构更加复杂的两层两环空间耦合链机构的自由度分析原理。通过推导两层两环空间耦合链机构的运动螺旋方程,建立耦合链带来的耦合关系的数学模型。基于运动螺旋方程,建立空间耦合机构中刚性子结构的判别方法和自由度分析原理。利用两层两环空间耦合链机构的等效子并联机构的分支运动螺旋系线性组合的特点可以实现自由度性质分析。两个典型的例子被用来说明提出方法的有效性。 相似文献
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An analytical method is presented for evaluation of the steady state periodic behavior of nonlinear systems. This method is
based on the substructure synthesis formulation and a MS (multiple scales) procedure, which is applied to the analysis of
nonlinear responses. The proposed procedure reduces the size of large degrees-of-freedom problem in solving nonlinear equations.
Feasibility and advantages of the proposed method are illustrated with the nonlinear rotating machine system as an example
of large mechanical structure systems. In addition, its efficiency for nonlinear response prediction will be shown by comparison
of other conventional methods. 相似文献
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分支轴系扭振分析的动态子结构矩阵法 总被引:10,自引:0,他引:10
介绍了一种适用于复杂分支轴系扭振分析的动态子结构矩阵法,该方法利用分支轴系之间的协调关系,将直串子结构动力分析的动态矩阵法与子结构模态综合法结合起来,从而大大简化了分支轴系的扭振分析。 相似文献
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Byungyoung Moon Jin-Wook Kim Bo-suk Yang 《Journal of Mechanical Science and Technology》1999,13(9):620-629
In this paper, a new method of analysis of a complex nonlinear vibration system is presented. Combining substructure synthesis and perturbation methods the computation cost for large mechanical system is considerably reduced. 相似文献
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柔性机械臂接触碰撞问题的研究 总被引:4,自引:0,他引:4
分析了柔性机械臂在碰撞前、碰撞阶段以及碰撞后的动力学特性,在子结构离散的柔性多体系统动力学的基础上,导出了描述这三个不同阶段的动力学方程。从运动的连续性获得各阶段的初始条件,通过仿真计算可确定碰撞开始和结束的时刻,并求得撞击力和机械臂抓手位移的时间历程 相似文献
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根据弹性连杆机构的特点,给出了一种基于传感器输出反馈,用于控制机构振动的模糊控制器的设计方法,研究了模糊论域的形成,偏差和偏差变化率的模糊化,控制输出的解模糊,以及通过模糊辨识获取模糊控制规则等问题,所给方法原理简单,计算便捷,最后,对一个四连杆机构的模糊振动控制进行了仿真研究,说明了该方法的正确性和有效性。 相似文献
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给出了一种大位移、变拓扑空间机构的动力分析方法。由物体相对坐标和有限元节点坐标描述系统的运动与变形,通过运动相容条件确定系统空间构形的连续性和唯一性,建立了变结构、刚柔多体系统动力学方程。并由算例表明了该方法的精度与效率 相似文献
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In recent years, considerable attention has been given to the analysis of flexible mechanisms. Analysis procedures often involve representing members of a particular mechanism by finite elements, and solving the derived system of governing equations for deflections and stresses. The inverse problem, which is one of design rather than analysis, is more difficult, and only a limited amount of work has been carried out in this area. In design, one must determine mechanism parameters that will satisfy specified stress and/or deflection conditions. In this paper a new procedure is presented for designing flexible mechanisms, and it is illustrated by an example of a planar 4-bar mechanism driven at a constant input rotational speed. Results for the example problem, using this new procedure, are found to converge to the optimum solution in fewer iterations than that required for previously published optimization techniques. 相似文献