Dynamic Response of Large Complex Segmentally Periodic Structures by the Symplectic Matrix Method

Author(s):  
M. Zhou ◽  
F.W. Williams
1960 ◽  
Vol 269 (4) ◽  
pp. 274-298
Author(s):  
Mihajlo D. Mesarović

2021 ◽  
Author(s):  
Federico Giusti ◽  
Francisco Mesa ◽  
Qiao Chen ◽  
Guido Valerio ◽  
Oscar Quevedo-Teruel

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Hao Deng ◽  
Xi Fang ◽  
Huachun Wu ◽  
Yiming Ding ◽  
Jinghu Yu ◽  
...  

In view of the numerical instability and low accuracy of the traditional transfer matrix method in solving the high-order critical speed of the rotor system, a new idea of incorporating the finite element method into the transfer matrix is proposed. Based on the variational principle, the transfer symplectic matrix of gyro rotors suitable for all kinds of boundary conditions and supporting conditions under the Hamilton system is derived by introducing dual variables. To verify the proposed method in rotor critical speed, a numerical analysis is adopted. The simulation experiment results show that, in the calculation of high-order critical speed, especially when exceeding the sixth critical speed, the numerical accuracy of the transfer symplectic matrix method is obviously better than that of the reference method. The relative errors between the numerical solution and the exact solution are 0.0347% and 0.2228%, respectively, at the sixth critical speed. The numerical example indicates the feasibility and superiority of the method, which provides the basis for the optimal design of the rotor system.


2016 ◽  
Vol 08 (02) ◽  
pp. 1650013 ◽  
Author(s):  
Q. Gao ◽  
H. W. Zhang ◽  
W. X. Zhong ◽  
W. P. Howson ◽  
F. W. Williams

In this paper, an accurate and efficient method is presented for analyzing the dynamic response of two-dimensional (2D) periodic structures. The algebraic structure of the corresponding matrix exponential is analyzed and, based on its special structure, an accurate and efficient method for its computation is proposed. Accuracy is maintained using the precise integration method (PIM), and great efficiency is achieved in the computational effort using the periodic properties of the structure and the energy propagation features of the dynamic system. The proposed method is compared with the conventional Newmark and Runge–Kutta (R–K) methods, and it is shown to be accurate, efficient and extremely frugal in its memory requirements.


2011 ◽  
Vol 94-96 ◽  
pp. 1979-1982
Author(s):  
Jie Gao ◽  
Ke An Chen

A study on SEA properties of periodically stiffened structure was accomplished based on the periodic theory. With application of certain software, a simulation was performed on a common periodically stiffened fuselage structure. The results indicate such modeling approach reflects relatively accurate property of subsystem in mid and high frequency range, while a remarkable improvement could also be expected in low frequency range, especially for complex structures. Such approach was approved as one reliable engineering method for solving dynamic response of periodic structures.


2021 ◽  
Vol 236 ◽  
pp. 02035
Author(s):  
Zhongyuan Shen ◽  
Xue Bai

Shear seismic response analysis is critical for seismic design of immersed tunnels. According to the structural characters of immersed tunnels and shear dynamic response of their joints, a multibody dynamic model consisting of multi-rigid body, shear hinge, and viscous damping hinge is proposed for shear response analysis, in which the dynamic stiffness of the shear hinge is divided into two stages based on a threshold. Following the discrete time transfer matrix method for multibody system dynamics (MS-DT-TMM), the mechanical model and mathematical expression of each tunnel element is derived first and then assembled for the whole tunnel system. A solution procedure is proposed to solve the shear dynamic response of immersed tunnels using the proposed multibody system model. It is shown that the MS-DT-TMM has the same computational accuracy as the finite element method (FEM) and the modeling process is more efficient and flexible when compared to FEM. Although the MS-DT-TMM discussed herein is only applied to shear response analysis, it can easily be extended to analyze axial force and bending moment of immersed tunnels leading to a complete, rapid yet accurate enough seismic analysis of immersed tunnels suitable for engineering practices.


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