On the Choice of the Numerical Contact Stiffness Parameter for the Modal Analysis

Titelangaben

Wittmann, Johannes ; Hüter, Florian ; Zahn, Aljoscha ; Tremmel, Stephan ; Rieg, Frank:
On the Choice of the Numerical Contact Stiffness Parameter for the Modal Analysis.
In: International Journal of Simulation Modelling. Bd. 21 (2022) Heft 4 . - S. 567-578.
ISSN 1726-4529
DOI: https://doi.org/10.2507/IJSIMM21-4-616

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Abstract

Modal analysis carried out within the Finite-Element-Analysis leads to natural frequencies and mode shapes. Using adjacent solids in linear dynamics generates a computational contact problem with several configuration parameters. Contact stiffness is of importance as it affects the accuracy and convergence behaviour of the results. Thus, an overlarge value leads to a locking phenomenon and causes ill-conditioned system matrices. This paper investigates whether recommendations for appropriate contact stiffnesses in static mechanics are also applicable to modal analysis. In fact, it can be observed that a significantly smaller contact stiffness than stated in the literature is also well suited for modal analysis. Furthermore, choosing the optimum range for the numerical contact stiffness for modal analysis depends on the order of the natural frequency and the corresponding vibration mode. The results of the simulations are validated against experimental modal analysis of a sample with identical elastic properties. The verified contact settings in the present paper permit a more realistic consideration of contact constraints in modal analysis.