STRUCTURED MODELING APPLIED TO FLEXIBLE HELICOPTER ROTOR BLADES

Global Recursive Dynamics is a previously developed rigorous reformulation of the mechanics of articulated trees. Structured Modeling is a method of creating simulations of articulated trees virtually without coding, by defining the configuration of the tree in a text file. The step-wise numeric time integration of the system is handled by generic code, based on Global Recursive Dynamics, which computes all the inertial effects. The code contains hooks for application specific routines to compute aerodynamic forces, engine torque, and any other external loads. This paper describes how the pre-existing helicopter simulation code Bladehelo was modified to use Structured Modeling, how the resulting new code was verified against the pre-existing version, lessons learned and resulting upgrades to the new formalism, and how the new capability was applied to modeling of blade flexibility.