Vibration suppression of a coupled horizontal beam system stimulated by complex excitations enabled with a boundary nonlinear oscillator

An elastically coupled beam system is a complex mechanical system composed of two or more beam-like structures interconnected by elastic elements or directly through a continuous medium. The current research related to coupled beam systems demonstrates that the use of reasonable nonlinear devices can effectively prevent vibration in elastically coupled beam systems. Considering that actual engineering structures are subjected to multiple excitations, the excitation frequencies of the external excitations often differ. The lack of relevant research has restricted the application of nonlinear vibration control theory in the vibration control of elastically coupled beam systems. This work establishes the model of a coupled horizontal beam system (CHBS) stimulated by complex excitations enabled with a boundary nonlinear oscillator (BNO). The model formulas of the CHBS stimulated by complex excitations enabled with a BNO are derived and solved. According to the analysis and discussion, the current method is good at predicting the lateral responses of the CHBS stimulated by complex excitations enabled with a BNO. Introducing the BNO effectively suppresses the peak lateral responses in the multi-order primary resonance regions of horizontal beam 1 and horizontal beam 2, where the nonlinear parameters of the BNO should be reasonably designed based on the actual situation. The BNO is not merely a vibration suppression device but also a vibration transmission device. Reasonable use of BNO can effectively suppress the vibration of the CHBS under different-frequency excitations.