
Structural Test Data Analysis & Failure Mode Interpretation
Analyze structural test data, identify failure modes, and generate aerospace qualification reports
What You Can Do
You can analyze static and fatigue test data from aerospace components, distinguish between real failure modes and test artifacts, establish statistical confidence in results, and generate certification-ready engineering reports. The skill helps you interpret physical behavior under load, determine root causes of structural failures, and validate finite element predictions against test evidence—enabling design review boards and certification authorities to make informed decisions.
Features
process ultimate load tests (ULT), limit load tests (LLT), and fatigue life characterization with structured interpretation
distinguish actual structural failures from test anomalies and artifacts using physics-based reasoning
calculate and report uncertainty bounds for test results across multiple test articles
systematically investigate unexpected behavior and early failures to inform design changes
compare finite element predictions against test data with quantified confidence and knockdown factors
generate engineering reports formatted for design authority and regulatory approval
establish statistically justified knockdown factors for structural design allowables
identify and filter out hydraulic anomalies, instrumentation errors, and environmental factors
Example Output
Example 1: Static Test Analysis Report
- Test Article: Wing rib panel assembly (3 articles tested)
- Ultimate Load: 145 kN (failure load) vs. 138 kN predicted (FE)
- Failure Mode: Skin-stringer debond initiating at rivet hole, consistent with analysis
- Confidence Interval (90%): 142–148 kN
- Knockdown Factor: 1.05 (minor underprediction from FE)
- Recommendation: Design acceptable; reduce knockdown from 1.15 to 1.08 for allowables
Example 2: Fatigue Test Summary
- Test Spectrum: 10,000 flight hours (accelerated test)
- Failure Mode: High-cycle fatigue crack in spar cap at stress concentration
- Test Articles: 2 of 4 completed full spectrum; 2 runout (no failure)
- Mean Life: 9,850 flight hours; 90% confidence lower bound: 8,920 flight hours
- vs. FE Prediction: Predicted 9,200 hours; test validates with +7% margin
- Root Cause: Stress riser magnitude 12% higher than modeling assumptions (geometry tolerance stack)
- Action: Revise stress concentration factor in FE; update design guidance for fabrication
Example 3: Anomaly Detection
- Observed: Test article 2 failed at 89 kN (vs. 140+ kN in articles 1, 3)
- Investigation: Hydraulic pressure transducer drift detected during load ramp; load cell cross-checked at 92 kN
- Conclusion: Test artifact—hydraulic control lag, not structural failure
- Statistical Action: Exclude article 2 from confidence interval (documented in report)
What's Included
- SKILL.md: Full structural test data analysis methodology with decision trees for failure classification
- Test Report Template: Engineering-ready format with sections for data summary, failure analysis, statistical results, and certification statements
- Statistical Calculator (Excel/Python snippet): Confidence interval and knockdown factor calculations for multiple test articles
- Failure Mode Decision Tree: Flowchart to distinguish structural failures from test anomalies and environmental factors
- FE Validation Checklist: Structured comparison framework for test-vs.-analysis reconciliation
Who It's For
- Structural test engineers — designing, executing, and analyzing aerospace component qualification tests
- Design engineers — validating finite element models and establishing design knockdown factors from test evidence
- Test program managers — interpreting test results and supporting certification documentation
- Certification engineers — preparing engineering reports for design authority and regulatory approval (FAA, EASA, etc.)
- Materials and structures specialists — investigating failure mechanisms and root causes in aerospace structures
Best For
- Static ultimate load and limit load test analysis for primary aircraft structures
- Fatigue life characterization and high-cycle fatigue failure investigation
- Root cause analysis of unexpected or early structural failures
- Multi-article statistical confidence interval and knockdown factor determination
- Test-versus-analysis reconciliation and finite element model validation
- Engineering report generation for design review boards and certification authorities







