Gust Loads Reconstruction for In-Service Support

Abstract

Gust and turbulence events are of primary importance in the estimation of limit loads and in the analysis of flight incidents. The estimation of limit loads is required during the design stage of an aircraft, whilst the analysis of flight incidents is requested for in-service support. The former requires accuracy whereas the latter requires conservatism and speed. A method for gust reconstruction based on numerical optimisation techniques is proposed in this work and validated on the response of aircraft models of increasing complexity to known input gust profiles. Satisfactory results are then obtained when applying the reconstruction framework to realistic events where the input gust profiles are assumed to be unknown. With the results obtained, a database of reconstructed gust profiles is then built and used to define the worst case gust conditions, following a new method proposed here that consists of a combination of the singular value decomposition technique, surrogate models and optimisation routines. The results of this application show that the underlying characteristics of gust and turbulence profiles can be used to define successfully the worst case gust conditions for aircraft design.
The second part of this work focuses on the harmonisation of in-service support within Airbus. To appraise incidents, the manufacturer is requested to perform an investigation into the nature of the exceedance and to indicate the remedial action, if any, to be performed before the aircraft can be released permanently back into service. Airbus' department of loads and aeroelasticity is responsible for assessing the loads exceedances on the reported flight and ground incidents on all Airbus aircraft. But, the current process for incident resolution has evolved organically over the years with site based responsibilities, which have followed the historical evolution of the Airbus organisation. This evolution resulted into a complex and intricate network, which has called for a general reorganisation and remodernisation. A new centralised solution is therefore proposed here as a result of a thorough analysis guided by the fundamentals of systems engineering practice. This centralised solution is designed in such a way as to incorporate the gust reconstruction method proposed in the first part of this work and new methods that may be proposed in the future.

Date of Award	12 May 2020
Original language	English
Awarding Institution	University of Bristol
Sponsors	Airbus (United Kingdom)
Supervisor	Thomas C S Rendall (Supervisor) & Jonathan E Cooper (Supervisor)