Nonlinear Vibration Control And Dynamic Analysis Of Composite Laminated Beams

Composite beam structures have been widely used in aerospace.Due to the high strength and the low density characteristics of the composite structures,the application is also growing rapidly.However,laminated composite beams tend to work under complex conditions,such as hygrothermal and thermal environments.In those environments,mechanical properties of composite beams will possibly vary significantly.As a result,a laminated composite beam will vibrate at higher amplitudes.Long-term high-amplitude vibrations damage the composite structures,especially if the external excitation frequency is close to one of the natural frequencies of the structure.This paper presents a passive efficient nonlinear energy sink(NES)to control the transverse vibration.The generalized Hamilton principle is applied to derive a dynamic model of the laminated composite beam coupled with the NES.Numerical simulations reveal the effects of temperature,moisture,and laying angle on natural frequencies.It is numerically found that the NES can rapidly reduce the vibration amplitude.Amplitude-frequency response curves show that the NES can reduce the amplitude to very low values for various temperatures,moisture levels,and laying angles.In a certain range of the NES parameters,different control effects are determined via an approximate analysis.It is demonstrated that the NES is a promising approach to control vibration of a laminated composite beam in complex environment.Furthermore,this paper also investigates nonlinear vibration reduction of composite laminated beams with elastic support at both ends.In this work,the two-dimensional polynomial is applied to identify the Bouc-Wen model,which is used to describe the hysteretic restoring force of the NiTi-ST.Besides,environmental factors of temperature and moisture are under consideration.Amplitude-frequency response curves demonstrate that the NiTi-ST is a promising nonlinear damper to reduce the amplitude for various temperatures and moisture.As a result,this paper provides a novel method for vibration suppression of composite structure fields.