A Multidisciplinary Framework for Aircraft Landing Gear Brake Actuation Design

Modern and complex aerospace systems are being developed and optimized to enable the transition towards more-electric and/or all-electric aircraft. The integration of these systems in new generation aircraft and the multi-physics interactions between them are causing a greater complexity in both the design and verification processes. To face this complexity, several tools that can support integrated modelling, simulation, optimization and testing across all the stages of the system design are being developed. In this context, the European Commission launched the Clean Sky 2 Joint Technology Initiative. This program is a public-private partnership which provides funding for research and development of the processes, tools and technologies that will enable the aviation industry to increase the demand for aircraft with reduced fuel consumption, noise and emission of pollutants. Under this initiative, the “ModellIng and Simulation tools for Systems IntegratiON on Aircraft” (MISSION) project aims to develop and demonstrate an integrated modeling, simulation, design and optimization framework incorporating model-based systems engineering principles. This thesis discusses the activities under the MISSION project and proposes a design platform including models library for landing gear brake system design, especially for the integration in a multidisciplinary design framework. In particular, physics - based models of different types of actuator for the landing gear brake system are developed, including servo-hydraulic and electro-hydrostatic actuators. These models will support sizing, evaluation and optimization tasks within the landing gear system platform, in the multidisciplinary framework. In the document, the main steps of the aircraft brake system design process are illustrated. The first step is focused on the architecture definition, which helps to explore, evaluate and select promising architectures for the candidate brake actuation systems. The second step illustrates the sizing and physics-based modelling activities of different such actuator configurations. In particular, electro-hydrostatic actuator brakes are addressed in the study. The dynamic models are built using the standard multi-domain modelling language Modelica, with open and commercial tools. These physics-based model libraries are developed in a hierarchical and modular way. The sizing models are developed to estimate preliminary geometric and performance characteristics based on first order approximations and implemented in MATLAB environment. In addition, formal requirement models were developed using open Modelica libraries. The last step presents a design optimization analysis, in order to evaluate the best performances in term of mass reduction of the brake actuator using sizing and simulation models. The methodology including trade-off analysis, design optimisation and so on is presented together with the associated results. All these activities are part of one of the work-package (System Design Activities) led by United Technologies Research Centre – Ireland.