Simulation and Modeling of Pitting, SCC and Exfoliation on Aircraft

This paper describes the development of an aircraft simulation and modeling analysis system for predicting the degradation of aircraft structures due to corrosion.  This includes identifying and modeling the detailed failure mechanisms for Pitting, Stress Corrosion Cracking (SCC) and Exfoliation forms of corrosion, which are the primary sources of corrosion related failures on aircraft. 

This will be achieved by extending the existing ACES software product developed by GCAS under Army contract to NAVAIR aircraft structures, materials and corrosion failure modes.  The existing ACES product already includes methods for simulating uniform, galvanic and crevice corrosion.  The software is composed of an assembly of physics-based procedural algorithms, empirical-statistical models from test data and heuristic AI methods for representing knowledge from subject matter experts and lessons learned.  Full 3-D geometric models of the aircraft are imported and geometry search/feature recognition are performed using parallel computing Graphical Processing Units (GPUs).  A unique Knowledge Acquisition Facility will be included that will allow end user organizations to update the Knowledge Base with new information as it becomes available in the future.

The proposed Accelerated Corrosion Expert Simulator for aircraft systems will have significant benefit and payback to NAVAIR by providing a tool to simulate the advent of corrosion on aircraft structures over time.  The benefit will come in the form of time and cost savings in anticipating corrosion during fleet and depot level inspections, improved understanding of the nature of aircraft corrosion due to pitting, SCC and exfoliation, and a knowledge acquisition & retention system that will continue to grow over time.  The benefit of the developed system extends far beyond NAVAIR to all agencies of DoD maintaining aircraft fleets (Army Aviation and Missile Command (AMCOM) and Air Force, Coast Guard and Marine Corps), including the aircraft manufacturers and their subcontractor suppliers; and commercial aircraft companies.