Multibody dynamics simulation and experimental investigation of a model-scale tiltrotor

Abstract

The objective of this investigation is to illustrate the steps involved in developing a multibody dynamics analytical model to simulate the dynamic response, aeroelastic stability, and blade loading of a soft-inplane tiltrotor wind-tunnel model and correlate that simulation with experimental data. The rotorcraft industry is currently developing requirements for a heavy lift transport rotorcraft that is expected to include, at a minimum, a 20-ton payload lift capability. Development of soft-inplane tiltrotor technology is beneficiai for providing viable lightweight hub design options for this future application. Experimental testing, either in flight testing or with a wind tunnel test article, is becoming prohibitively expensive. Advanced simulation and modeling of these complex tiltrotor hub configurations using multibody dynamics analyses may prove to be an alternative to such expensive experimental verifications in the future. The use of multibody dynamics analyses to predict and reduce the risk of encountering aeromechanical instabilities and adverse loading situations for a soft-inplane tiltrotor hub design is detailed in this investigation. Comprehensive rotorcraft-based multibody analyses enable simulation and modeling of the rotor system to a high level of detail such that complex mechanics and nonlinear effects associated with control system geometry and joint free-play may be considered. The influence of these and other nonlinear effects on the aeromechanical behavior of the tiltrotor model is examined in this study. Copyright © 2005 by the American Helicopter Society International, Inc. All rights reserved