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A Modal Synthesis Technique for Determining Dynamic Properties for a Structure for Mass and Stiffness Changes
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Abstract
The assembly and particularly the reduction of the mass and stiffness matrix for a large system can be a significant portion of the computational cost of finding the mode shapes and natural frequencies. Therefore, parameter studies for design purposes can be prohibitive if these matrices are reassembled and reduced for each change. The purpose of this paper is to outline the procedure for using the modes of the original system to determine the dynamic characteristics of the changed system. The method also results in computational savings for boundary condition changes and for large systems that are nearly-symmetric except for a few mass and stiffness changes.
To illustrate the method several changes are made to a ladder frame. The results from an analysis using the reconstructed mass and stiffness matrices and the modal synthesis technique are compared to show the accuracy and freedom requirements.
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Citation
Vail, C., "A Modal Synthesis Technique for Determining Dynamic Properties for a Structure for Mass and Stiffness Changes," SAE Technical Paper 740329, 1974, https://doi.org/10.4271/740329.Also In
References
- Hurty W. C. “Vibration of Structural Systems by Component Mode Synthesis,” Proceedings of American Safety of Civil Engineers 85 EM4 August 1960 51 69
- Neubert V. H. Raney J. P. “Synthesis of Vibrating Systems,” The American Society of Mechanical Engineers New York, NY November 1971 124
- Davis J. C. “Modal Modeling Techniques for Vehicle Shake Analysis,” Automotive Engineering Congress Detroit, Michigan January 1972 SAE Paper No. 720045
- Klosterman A. L. “A Combined Experimental and Analytical Procedure for Improving Automotive System Dynamics,” Automotive Engineering Congress Detroit, Michigan January 1972 SAE Paper No. 720093
- Benfield W. A. Hruda R. F. “Vibration Analysis of Structures by Component Mode Substitution,” AIAA Journal 9 7 July 1971 1255 1261
- MacNeal R. H. “The NASTRAN Theoretical Manual,” NASA SP-221 NASA Washington, D.C. 1970