Analysis & Test

Welcome to the ERSI Analysis & Test committee website. A list of the current and previous round robin activities are listed below, along with all the associated files available for download.

• 2023 Validation of Fatigue Crack Growth Modeling Solutions using Measurements Collected on API X65 Piping Specimens
• 2022 Interference Fit Fastener Round Robin (in-work)
• 2022 Walker/Newman IRAD (in-work)
• 2022 Cx Variability Round Robin
• 2022 Boeing Spectrum Challenge
• 2021 Stress Intensity Factor Round Robin
• 2021 AFGROW Workshop Round Robin
• 2019 DST Assist Wide Plate spectrum challenge
• 2019 Interference Fit Fastener Round Robin
• 2017 Cx Round Robin
• 2017 AFGROW Workshop Round Robin

Interference Fit Fastener Round Robin (2022, in-work)

Objective: The primary objective is to establish a set of reference stress analyses agreed upon by the working group, as well as establish the baselines stress state that can be utilized for follow-up phases. Additionally, the analyses can be utilized to characterize: 1.      The onset of plastic deformation and the bounds of elastic vs. plastic regimes 2.      The relationship between far field loading and local strain cycles 3.      The stress state dependency as a function of key factors (e.g. interference level, modeling assumptions, remote loading)

Inputs ERSI - Analysis Methods Subcommittee - Interference Fit Fastener Phase I Round Robin Problem v4.docx ERSI IFF Round Robin Results Template_Group 1_v1.xlsx

Submissions IFF_Group1_-10ksi_Summary_r1v0.xlsx IFF_Group1_30ksi_Summary_r1v0.xlsx IFF_Group2_0.3%_Summary_r0v1.xlsx IFF_Group2_1.2%_Summary_r0v1.xlsx Submission Summary v2.xlsx

Meetings ERSI_FCG Analysis  Test_committee_IFF Overview.pptx ERSI_FCG Analysis  Test_committee_IFF Overview_r0vf.pptx ERSI_FCG Analysis  Test_committee_IFF_A10_work_01112023.pptx ERSI_FCG Analysis  Test_committee_IFF_update_01102023.pptx ERSI_IFF_Working_Group_022323_r0v1.pptx ERSI_IFF_Working_Group_051123_r0v1.pptx ERSI_IFF_Working_Group_082522_r0v1.pptx ERSI_IFF_Working_Group_092122_r0v0.pptx ERSI_IFF_Working_Group_092222_r0vf.pptx ERSI_IFF_Working_Group_02232023_r0v0.pptx ERSI_IFF_Working_Group_07142022_r0v0.pptx ERSI_IFF_Working_Group_07142022_r0v1.pptx ERSI_IFF_Working_Group2_r0v0.pptx ERSI_IFF_Working_Group3_r0v0.pptx

Cx Variability Round Robin (2022, completed)

Objective: Recent discussion within the ERSI Analysis Methods & Testing Committee have identified a need to perform a round-robin exercise focusing on how uncertainty in fatigue response due to the random variability in residual stresses at Cold Expanded (CX) fastener holes can be captured in damage tolerance analysis (DTA). This round-robin seeks to address the following: ·        Identify the sensitivity of DTA capabilities to variability in a CX fastener hole treated within specification ·        Identify the impact of using computational, empirical, or combined residual stress results in DTA ·        Anonymously compile ERSI community results for the above listed objectives for group comparison-to-test ·        Derive best-practices guidance from comparisons and in-depth-technical review by the ERSI community

ERSI - Analysis Methods Subcommittee - DTA for Variability in CX RS Round Robin.docx

Stress Intensity Factor Round Robin (2021, completed)

Objective: The primary objective of the Stress Intensity Factor (SIF) round robin was to evaluate differences between available SIF solutions for a single corner crack at a fastener hole with remote uniform tension loading. The evaluations included not only the root SIF solution but any corrections to account for single vs multiple cracks, finite width, and hole offset. These solutions were compared to explicit Finite Element Analysis (FEA) results of each case. Any findings were intended to drive improvements to solutions available to the fracture mechanics community.

ASIP Conference Presentation_ERSI SIF Round Robin.pdf ERSI-2021-01 Stress Intensity Comparison Round Robin & Data.pdf ERSI-2021-01 Stress Intensity Comparison Round Robin.pdf ICAF2023_ERSI_Final.pdf SIF Round Robin Data Summary.xlsx Cross-Comparisons of Stress Intensity Factors from Various Sources - The Pathway to Improved SIF Solutions.pdf SIF Comparison matrix - ERSI Round Robin.pdf

Cx Round Robin (2017, completed)

Objective: To identify the random and systematic uncertainties associated with Damage Tolerance Analyses (DTA) that incorporate residual stresses produced by Cold Expansion (Cx) of fastener holes. Many factors influencing the total uncertainty have been discussed and are currently under investigation by various members of the ERSI team. For the first round-robin exercise, the focus 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). Specific input data will be provided to each analyst participating in the exercise to minimize the random uncertainties associated with these types of analyses. The analyst is free to use any means to incorporate the residual stress into the DTA, any software suite, etc., however it’s important that the analyst adheres closely to the guidance so that the variability in the predictions will be limited to the aspects left to analyst’s discretion.

Inputs ERSI - Analysis Methods Subcommittee - Round Robin.docx Residual Stresses.xlsx Results Template.xlsx

Misc Other ERSI Round Robin Stress Intensity Comparisons.xlsx Round Robin Test Data Final.xlsx

Publications E08-ASTM-ESIS-Pilarczyk 2020 successful round robin analyses resulting from the ERSI working group.pdf ICAF 2019 - Summary of Recent Round Robin Life Prediction Efforts for Crack Shape and RS Effects.pdf Robert Pilarczyk - ASIP 2019 Presentation.pdf

Results Key Modeling Factors Summary.pdf Round Robin Predictions and Test Data.xlsx

AFGROW Workshop Round Robin (2017, completed)

Objective: The purpose of this round robin exercise is to determine the variability of users, given the same loading spectrum, material data, and Initial Flaw Size (IFS) to predict the evolution of the crack front shape and the total life of a given geometry using the AFGROW framework as the life prediction tool. Certain aspects of the AFGROW framework will be provided for common use by each participant, and others will be left to the user's discretion. It is important that each participant follow this guidance so that variability in the predictions is limited to the aspects left to user discretion.

AFGROW Workshop Round Robin.pdf AFGROW Round Robin Questionnaire.pdf Tom Mills-Scott-Fawaz AFGROW Round Robin Corner Crack at Center and Offset Hole - AFGROW Workshop 2017.pdf Prediction Results Template.xlsx Crack History Correlation.xlsx Marker-Data.zip Spectrum.zip