FEATURE OF D16AT ALUMINUM ALLOY DEFORMATION RELIEF EVOLUTION UNDER VARIABLE AMPLITUDE LOADING

Abstract

Information of aircraft structure and, basically, material state obtaining is the main task for residual life estimation. New approaches of non-destructive testing technology develop Structural Health Monitoring systems, the key elements of which are sensors. Developed in NAU Deformation Relief (DR) fatigue sensor is compact specimen of D16AT alclad aluminum alloy which fasten to controlled object. Under cyclic loading there is the intensive plastic deformation of alclad, leading to DR formation on the sensor surface which acts as the indicator of the cumulated damage. In this article was proposed to control DR evolution of the aircraft skin, which is produced from D16AT. The test specimen alclad surface control zones were inspected with interfere optical nano-profiler Micron Alpha under variable amplitude loading. During surface monitoring were defined DR saturation, surface roughness and surface plastic deformation parameters. It was estimated features of the DR parameters under MiniTWIST standardized load sequences.