2019 Interference Fit Fastener Round Robin

Point of Contact(s): Jake Warner

Objective: The focus of this round-robin will be on systematic uncertainties, or the uncertainty associated with the system or process used by the analyst (also known as epistemic uncertainties or model-form uncertainties) in the incorporation of an Interference Fit Fastener (IFF) into crack growth analysis. To ensure that the systematic uncertainties are accurately identified by this effort, analysts were encouraged to collaborate as they normally would in responding to a real world scenario, but not to share prediction results with other individuals submitting predictions until after the submission period ends. The intent being to prevent a bias in predictions toward one analyst’s submission. Specific input data was provided to each analyst participating in the exercise to minimize the random uncertainties. The analyst was free to use any means to incorporate the IFF into the crack growth analysis, however the analyst adhered closely to the guidance so the variability in the predictions will be limited to the aspects left to analyst’s discretion. Analysts were not to adjust any of the provided input data in any way. Analysts were permitted to provide multiple predictions if they desire, but it is required that the analyst identify a single prediction as the prediction they feel would best match the test data. Fatigue test data for the scenarios involved in this round-robin were provided to each participant at the conclusion of the round robin. Submissions results were made anonymous and compared to test data to identify analytical approaches that worked well and to define best practices for future efforts.

Inputs IFF Prediction Challenge

Submissions IFF Prediction Challenge_A-10 and F-4 IFF Prediction Challenge_B-2 Spirit IFF Prediction Challenge_B-21 Raider IFF Prediction Challenge_F-15 Strike Eagle IFF Prediction Challenge_F-16_Fighting Falcon IFF Prediction Challenge_F-111 Aardvark IFF Prediction Challenge_KC-46 Pegasus IFF Prediction Challenge_P-61 Black Widow IFF Prediction Challenge_SR-71 Blackbird IFF Prediction Challenge_U-2 Dragon Lady

Results Baseline Results 4% Interference Results 6% Interference Results ERSI IFF Analytical Round Robin (ASIP 2020)