Finite Element Analysis and Software Development  


www.tesys.it 
previous  next  contents 
Rotary actuator for Yak/AEM130 aircraft.
The actuator will be used in the new european military aircraft M346 (formerly, Yak/AEM130) for the extension and retraction of inboard and outboard slat surfaces. Each actuator is composed by three fixed ring gears and two movable ring. These rings also house the internal gear mechanism. The primary aim of the structural analysis is to establish the deflection state of the structure at different actuation or slat angles in order to avoid jam, anomalous wear or overloading conditions in the internal gears. The structure must be analyzed at different angles because the value of the external load changes with the slat position and the ratio of tangential force to radial force varies as well.
In order to calculate the kinematic variables in function of the slat angle and obtain the different configurations of geometry, loads and boundary conditions, the model was prepared parametrically using the capabilities of APDL language of ANSYS. In this kind of structures with many sliding surfaces and critical tolerances the contacting problem must be resolved using nonlinear contact or gap elements.
A great mesh detail and relatively short time of execution can be obtained by separating the linear and nonlinear portions of the model by using a substructuring approach. In the present case each separate part of the model constitutes a different substructure. All substructures are then assembled at their common and matching interfaces with the nonlinear contact elements to form the main structure. The whole model has a total of 200,000 degrees of freedom. In this way only the nonlinear elements are recalculated at each iteration whereas the linear superelements remain unchanged.