Date of Award
8-17-2002
Document Type
Thesis
Abstract
Two related problems are addressed in this thesis. The first one is for order reduction of conservative vibrating systems with piecewise linear nonsmooth nonlinearities of arbitrary dimension. Linear-based, PMM-based and LELSM-based order reduction transformations are applied. The technique is applied to multi-degree-of-freedom systems with nonsmooth clearance, deadzone, bang-bang, and saturation nonlinearities. The resulting approximate frequencies are compared with those obtained from numerical simulations. The second technique is eigenstructure assignment of n-degree-of-freedom conservative vibrating systems with nonsmooth nonlinearities. Three distinct control strategies which utilize methods for approximating the NNM frequencies and mode shapes are employed. First, PMM for approximating NNM frequencies is used to determine n constant actuator gains for eigenvalue placement. Second, an approximate single-degree-of-freedom reduced model is found with one actuator gain for the mode to be controlled. The third strategy allows the frequencies and mode shapes (eigenstructure) to be placed by using a full n x n matrix of actuator gains and employing LELSM for approximating NNM frequencies and mode shapes.
Recommended Citation
Lu, Rongdong, "Order reduction and eigenstructure assignment for nonsmooth vibrating systems: a nonlinear normal modes approach" (2002). Engineering . 156.
https://ualaska.researchcommons.org/uaf_grad_engineering/156
Handle
http://hdl.handle.net/11122/6288