Study on the camber angle of an aircraft radial tire: stress, contact, damage, and modal behaviors

Abstract

During the landing process, there often exists a camber angle θ between the aircraft and the ground, complicating the tire-ground contact behavior and the consequential damage evolution. In this paper, a finite element analysis considering the cord-rubber composite structure of the aircraft radial tire, along with the hyperelasticity and Mullins effect of rubber is performed to investigate the effect of the camber angle θ on its stress distribution, the tire-ground contact behavior, the damage evolution, and the vibration characteristics. According to the stress analysis of the numerical results, under different θ, the tire shoulder is always the most vulnerable location where the stress concentrates the most and the Mullins damage indicator accumulates the most. The tire-ground contact behavior under different θ is analyzed and it is found that the vertical stiffness-displacement curves can be divided into three regimes due to the different involvement of the tire shoulder in the tire-ground contact process. The largest Mullins damage is first detected in the cross-section surface which is 30° from the middle of the contact region while as the load increases, the Mullins damage in the contact region increases rapidly and exceeds that in the 30° surface. Moreover, the vibration characteristics of the non-damaged tire and the damaged tire are extracted and compared. Different degrees of decrease in the natural frequencies are observed while no change is detected in modal shapes when Mullins damage is introduced. This paper reveals the importance of the tire shoulder in the tire structure design and the tire-ground contact process, and provides an insight into the damage monitoring technique of the aircraft radial tire.