Nonlinear Flutter Time-domain Analysis of Control Surfaces with Freeplay in a Certain Airplane

Abstract

The freeplay of control surfaces is one of typical types of structural nonlinearity,which is caused by design,manufacture,assembly,and it may easily lead to the limit cycle oscillation(LCO).LCO is usually shown as equal amplitude vibration,and it may influence the integrity of structure and cause structural failure if the amplitude is too large.Nonlinear flutter analysis method in time domain for control surface with freeplay is investigated and used to compute the nonlinear flutter result of certain aircraft.T he calculation result is compared with that achieved by frequency domain method.The results show that the critical flutter velocity of LCO is good compliance with frequency.The time domain analysis method can precisely calculate the nonlinear critical velocity of aircraft control surface freeplay,and is feasible to predict the LCO of control surface,which can also be a method to verify if it meets the airworthiness standards.

Keywords

• control surface
• freeplay
• nonlinearity
• lco
• flutter
• time domain