Some observations to recent full-scale fatigue tests

icaf2023 Tracking Number 44

icaf2023 presentation

Today, full-scale fatigue testing are required as means of compliance for proof of structures to certify both composite and metallic structures. This paper presents the common practice to set up and to monitor the full-scale fatigue testing of aircraft control surfaces done in GKN Aerospace Services Ltd. These tests include Bombardier projects on testing ailerons, rudder and elevator, etc, and recently the Dassault F6X project of testing wing movables consisting of flap, flaperon, aileron and airbrake. Although full scale fatigue testing have been applied in the past to demonstrate compliance for aircraft certification, some recent full-scale fatigue testing results reveal some issues on structure design philosophy, measurement techniques, and correlations. This paper outlines some findings based on the results observed using standard practice and measuring techniques to validate the structural analysis. Buckling found during fatigue test case has been monitored throughout the test duration. Strains and deflection surveys are used for correlation to the predictions, and are used to check test consistency. In cases of crack growth from saw-cuts, predictions and monitoring to the crack growth are presented. Finally, from the above mentioned there is a need to review the-state-of-arts measurement techniques to support full scale tests. New techniques such as DIC is applied with some level of success but more reliable and mature measuring techniques are still required to be explored in industries.