Bifurcation analysis of dual-sidestay landing gear locking performance considering joint clearance

Sidestay lock mechanism is an important part of landing gear system, and the locking performance can be analyzed based on changes in its stability. However, during numerical continuation analysis of fully-rigid dual-sidestay landing gear without clearance, it has been found that the appearance of bifurcation points does not necessarily imply that both sidestay links can be locked synchronously. This problem reveals the limitations of fully-rigid model with ideally-articulated in solving dual-sidestay mechanisms with extremely high motion sensitivity. Therefore, this study proposes a bifurcation analysis method for synchronous locking of dual-sidestay landing gears, which takes into consideration the joint clearance. For in-depth analysis of this problem, we initially build kinematic and mechanical models of a landing gear mechanism that consider joint clearance. Then, the models are solved based on continuation. The fundamental causes of synchronous locking are discussed in detail, and the number of bifurcation points is found to be closely related to whether the landing gear is completely locked. Finally, the effects of structural parameters on the synchronous locking are analyzed, and the feasible region of parameters satisfying synchronous locking condition is given, which agrees well with the test results.