Abstract
The Non-Linear Resonant Decay Method (NL-RDM) identifies a model based in linear modal space comprising the underlying linear system and a small number of additional terms that represent the nonlinear behaviour. The method is applied to a 'wing / store' structure which consists of a rectangular 'wing' with two 'stores' suspended beneath it and able to rotate on non-linear springs with a nominally hardening characteristic. The basic system is identified using classical modal methods and it is shown that the natural frequencies actually decrease initially with increasing excitation, consistent with softening non-linearity. On closer inspection, it is seen that the non-linearity subsequently hardens significantly, so the non-linear mechanism is actually of a combined softening / hardening stiffness type. The NL-RDM is applied to the model using two shakers and non-linear terms identified for the first four modes; the first three modes show a clear direct cubic stiffness term but no evidence of softening behavior.
Original language | English |
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Title of host publication | Proceedings of the 2004 International Conference on Noise and Vibration Engineering, ISMA|Proc. Int. Conf. Noise Vib. Eng. ISMA |
Editors | P. Sas, M. Munck |
Pages | 2155-2168 |
Number of pages | 13 |
Publication status | Published - 2004 |
Event | Proceedings of the 2004 International Conference on Noise and Vibration Engineering, ISMA - Leuven Duration: 1 Jul 2004 → … |
Conference
Conference | Proceedings of the 2004 International Conference on Noise and Vibration Engineering, ISMA |
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City | Leuven |
Period | 1/07/04 → … |