A novel modal superposition method with response dependent nonlinear modes for periodic vibration analysis of large MDOF nonlinear systems

2020 ◽  
Vol 135 ◽  
pp. 106388 ◽  
Author(s):  
Erhan Ferhatoglu ◽  
Ender Cigeroglu ◽  
H. Nevzat Özgüven
Author(s):  
Li Li ◽  
Ben S. Zhong ◽  
Zi Y. Geng ◽  
Wei Sun

Structural shape reconstruction is a critical issue for real-time structural health monitoring in the fields of engineering application. This paper shows how to implement structural shape reconstruction using a small number of strain data measured by fiber Bragg grating (FBG) sensors. First, the basic theory of structural shape reconstruction is introduced using modal superposition method. A transformation is derived from the measured discrete strain data to global displacement field through modal coordinate, which is the same for strain mode shape superposition and displacement mode shape superposition. Then, optimization of the sensor layout is investigated to achieve the effective reconstruction effect. Finally, structural shape reconstruction algorithm using modal superposition method is applied in experiments. The experiment results show that the reconstructed displacements match well with those measured by a laser displacement sensor and the proposed approach is a promising method for structural shape reconstruction.


2011 ◽  
Vol 421 ◽  
pp. 743-749
Author(s):  
Xiao Ming Wu ◽  
Chun Liu

Abstract. The computation of the responses and their design sensitivities play an essential role in structural analysis and optimization. Significant works have been done in this area. Modal method is one of the classical methods. In this study, a new error compensation method is constructed, in which the modal superposition method is hybrid with Epsilon algorithm for responses and their sensitivities analysis of undamped system. In this study the truncation error of modal superposition is expressed by the first L orders eigenvalues and its eigenvectors explicitly. The epsilon algorithm is used to accelerate the convergence of the truncation errors. Numerical examples show that the present method is validity and effectiveness.


2013 ◽  
Vol 475-476 ◽  
pp. 1474-1478
Author(s):  
Hong Qiu Li ◽  
Guo Ping Chen

This paper presents a study on the dual-coupling characteristics between elastic plate and acoustic cavity. Modal superposition method was employed to analyze sound transmission in the plate-cavity-plate system and cavity-plate-cavity system. Impedance and mobility methods were also adopted which were easy to investigate the characteristics between the structural and acoustic systems. The expression of sound transmission between plate-cavity-plate system and cavity-plate-cavity system were given.


1979 ◽  
Vol 101 (2) ◽  
pp. 134-141 ◽  
Author(s):  
V. N. Shah ◽  
G. J. Bohm ◽  
A. N. Nahavandi

A modal superposition method for analyzing nonlinear structural dynamic problems involving impact between components is developed and evaluated. The finite-element method is used to express the equations of motion with nonlinearities represented by pseudo force vector. Three test problems are solved to verify this method. This has demonstrated the applicability of this method to seismic analysis of large, complex structural systems. It is concluded that the modal superposition method has a significant cost advantage over the direct integration method for problems with large wave fronts and the source of nonlinearities restricted to a limited portion of the structure.


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