Load spectra are inherently affected by landings, and their accurate determination cannot be pursued without considering the landing event itself. Landing event characterization is fundamental when aircraft structural assessment has to be performed. Two approaches are compared, using displacements and forces at specific airframe locations, respectively, as the link between the dynamic and structural domains. The dynamic analysis is performed first, calculating a set of intermediate parameters that are provided as input to the subsequent structural analysis. This approach divides the complex landing problem into two separate domains, namely a dynamic domain, which is ruled by a multibody model, and a structural domain, which relies on a finite element model (FEM). In the present work, a coupled sequential simulation strategy is proposed and experimentally verified. The structural response to rotorcraft landing is an underrated topic in the open scientific literature, and tools for the landing event simulation are lacking. An effective means to create a structural response database relies on the modeling and simulation of the items and phenomena of concern.

Landing, especially when considering rotorcrafts, is thus crucial in determining the operational load spectrum, and accurate predictions on the actual health/load level of the rotorcraft structure cannot be achieved unless a database comprising the structural response in various landing conditions is available. Maximum loads acting on aircraft structures generally arise when the aircraft is undergoing some form of acceleration, such as during landing.

Sequential manual transmission rotator