Proposal Presentation:

Multiaxial Fatigue Analysis of Composite Tension-Torsion Straps for Rotor Systems

Ryan T. Casey

Tension-Torsion Strap

http://upload.wikimedia.org/wikipedia/commons/2/29/Md500e-rotorhead-aradecki-070316-01.jpg

McDonnell Douglas MD-500E Rotor Head

Common Rotor System Configuration for T-T Strap

Tension-Torsion Strap

Flap Hinge

Lead/Lag Hinge

Pitch Housing

Blade Attachment

Loading Conditions of T-T Strap

1. CF Load2. Torsional Twist due to Pitch Input3. Small Flatwise Bending due to Pitch Housing Deflection

Methodology

• Classical Laminate Theory– Material Properties (E, G, etc…)

• Develop FEA model – Determine Notch Factors

• Develop Stress Spectrum

• Multiaxial Fatigue Failure Theories:– Max Principal Strain, Von Mises, Max Shear

Strain, Lohr-Ellison, Kandil-Brown-Miller

Expected Results

• Fatigue Life Range Prediction for Composite T-T Strap

• FEA Models (ANSYS Workbench)

• Equivalent Material Properties from Laminate Theory

• Notch Factors

Project Task Milestones

Project Task Milestones Due Date

Research in Classical Laminate Theory &Classical Laminate Theory February 12, 2010

Determine Design Parameters/Requirements February 12, 2010

Common Stress Spectrum Creation February 19, 2010

Complete FEA of Metal Strap Configuration March 5, 2010

Composite Design concurrent w/ FEM & Fatigue Analysis March 5, 2010

Finalize Composite Strap Design March 19, 2010

Complete FEM & Fatigue Life Analysis March 26, 2010

Questions

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