Scaling method of aeroelastic model considering geometric nonlinearity

The high-aspect-ratio flexible wing has become the main structural type of emerging aircraft with the increasing demand and performance improvement of aircraft. The wing type holds the inherent characteristics of high lift-to-drag ratio, large deformation and low weight, and the geometric nonlinear effect is obvious. However, the high aspect ratio will lead to larger wing deformation, resulting in nonlinear aeroelastic behavior. To evaluate the nonlinear aeroelastic behavior and reduce the risk and cost of the design, it is necessary to design a scaling model and conduct wind tunnel test with a scaling model to represent the aeroelastic characteristics of real aircraft. Based on this purpose, traditional linear scaling approaches are applied first. Two linear scaling methods, stiffness-mass coupled matched modal response and stiffness-mass decoupled matched modal response, and continually optimizes the design parameters of scaled model structure to meet the target values. Then, a new method named the nonlinear static deformation and mode collaborative optimization of the dynamic finite element model is proposed, which employs two different optimization subroutines to match the nonlinear static response and the mode shapes according to the full model equivalent static loads. The results show that, compared with the traditional linear scaling model, the nonlinear aeroelastic behavior of the full-size aircraft can be reproduced better by using the geometric nonlinear scaling method. © 2019, Editorial Board of JBUAA. All right reserved.