从连续介质力学非线性位移-应变关系出发,导出计入应力刚化效应的柔性梁变形能表达式。利用哈密顿变分原理和浮动框架有限元方法(Finite Element Method of Floating Frame of Reference,简记为FEMFFR)导出了匀速转动非惯性系中曲梁的...从连续介质力学非线性位移-应变关系出发,导出计入应力刚化效应的柔性梁变形能表达式。利用哈密顿变分原理和浮动框架有限元方法(Finite Element Method of Floating Frame of Reference,简记为FEMFFR)导出了匀速转动非惯性系中曲梁的动力学方程。通过数值仿真分析了曲梁的旋转软化(Spin Softening)和应力刚化(Stress Stiffening)效应,并与ANSYS软件仿真结果进行了对比,从结构动力学特征值角度验证了基于连续介质力学非线性位移-应变关系为高速旋转曲梁引入应力刚化效应的方法的正确性。由于曲梁结构不再像直梁结构那样拥有独立的纵向和横向振动模态,为此讨论了改进的Craig-Bampton模态综合法在一般运动曲梁系统中的应用及其缩减策略,为利用浮动框架有限元方法建立满足基于小变形假设的高速旋转柔性曲梁动力学模型提供了参考。展开更多
To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is dev...To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is developed by using the transfer matrix method of multibody system(MS-TMM), the transfer matrix of non-u- niform beam is derived, and the natural frequencies are computed. Compared with the numerical assembly method (NAM), the results by MS-TMM have good agreement with the results by FEM, and are better than the results by NAM. When using the high precision method, the global dynamic equations of the complex multibody system are not needed and the orders of involved system matrices are decreased greatly. For the investigation on the re- verse problem of the physical parameter identification of multibody system, MS-TMM and the optimization tech- nology based on genetic algorithms(GAs) are combined and extended. The identification problem is exchanged for an optimization problem, and it is formulated as a global minimum solution of the objective function with respect to natural frequencies of multibody system. At last, the numerical example of non-uniform beam with attach- ments is discussed, and the identification results indicate the feasibility and the effectivity of the proposed aop- proach.展开更多
文摘从连续介质力学非线性位移-应变关系出发,导出计入应力刚化效应的柔性梁变形能表达式。利用哈密顿变分原理和浮动框架有限元方法(Finite Element Method of Floating Frame of Reference,简记为FEMFFR)导出了匀速转动非惯性系中曲梁的动力学方程。通过数值仿真分析了曲梁的旋转软化(Spin Softening)和应力刚化(Stress Stiffening)效应,并与ANSYS软件仿真结果进行了对比,从结构动力学特征值角度验证了基于连续介质力学非线性位移-应变关系为高速旋转曲梁引入应力刚化效应的方法的正确性。由于曲梁结构不再像直梁结构那样拥有独立的纵向和横向振动模态,为此讨论了改进的Craig-Bampton模态综合法在一般运动曲梁系统中的应用及其缩减策略,为利用浮动框架有限元方法建立满足基于小变形假设的高速旋转柔性曲梁动力学模型提供了参考。
基金Supported by the National Natural Science Foundation of China(10902051)the Natural Science Foundation of Jiangsu Province(BK2008046)~~
文摘To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is developed by using the transfer matrix method of multibody system(MS-TMM), the transfer matrix of non-u- niform beam is derived, and the natural frequencies are computed. Compared with the numerical assembly method (NAM), the results by MS-TMM have good agreement with the results by FEM, and are better than the results by NAM. When using the high precision method, the global dynamic equations of the complex multibody system are not needed and the orders of involved system matrices are decreased greatly. For the investigation on the re- verse problem of the physical parameter identification of multibody system, MS-TMM and the optimization tech- nology based on genetic algorithms(GAs) are combined and extended. The identification problem is exchanged for an optimization problem, and it is formulated as a global minimum solution of the objective function with respect to natural frequencies of multibody system. At last, the numerical example of non-uniform beam with attach- ments is discussed, and the identification results indicate the feasibility and the effectivity of the proposed aop- proach.