Validating Advanced Damage Resistance for Next Generation Propulsion

AFWERX Alignment: The proposed effort supports AFWERX Focus Areas of Gas Turbine Engine Propulsion, where propulsion-related ideas and technologies associated with sustainment, residual stress for fatigue, and improving the industrial base are highly sought. In this project, the team will use an Air Force developed patent to demonstrate damage resistance in additive manufactured (AM) blades. Successful results from this project will demonstrate accelerated fatigue testing for rapid qualification, repeatability in an AM process, and a viable path forward to reduce maintenance, repair, and overhaul costs for next generation gas turbine engine. Ā The Problem: The current state of gas turbine engine blades and bladed disks (Blisks) shows damage as a costly issue in the future sustainment of advanced systems. Specifically, the value of an individual Blisk can be as high as $700k. Considering the 1st stage fan for the F119 engine, early 2020 information implies that newly manufactured spares for replacement cost the DAF more than $10M. Extrapolating this information about Blisks to multiple DoD Blisks from multiple engines over the coming decades will lead to spare Blisks costing billions of dollars. AM is an enabling technology that can accelerates agile and affordable solutions to the problem of future Blisk sustainment costs while improving the performance. AM can produce parts with new performance attributes like reduced weight, as one-off or small batches, at lower costs, using less energy and emitting less greenhouse gases. However, because many factors are needed to control AM processes, fatigue performance of AM parts are low and difficult to predict. Therefore, AM is not practical for many high-performance DoD parts such as gas turbine engine blades/Blisks. Ā Proposed Solution/Innovation: The work being proposed to AFWERX addresses many needs in the Gas Turbine Engine Propulsion Focus Area by implementing an AM method technology to inherently make parts that are resistant to damage. The specific innovation proposed with this project is the use of the Inherent Damping via AM Processes (i-DAMP) solution to design a compressor blade with a known defective at a high stress region. The primary purpose of the project is to show fatigue resistance of LPBF parts by comparing baseline/pristine blade data to the life of strategically notched blades as well as notched + i-DAMP blades. The proposed work will be the preliminary example of i-DAMP effectiveness against significant damage prior to the design and demonstration of an i-DAMP Blisk (Phase II). Additional assessment during this project will be geometric integrity via optical metrology, computed tomographic (CT) scanning of specimens, strength testing of coupons, and structural dynamic assessment showing vibration suppression capability.