Model Preparation (+2)
Model Preparation
- Ensure static convergence before modal analysis
- Use appropriate segment lengths for accurate mode shapes
- Include all relevant objects in the analysis
- Consider boundary conditions (fixed vs. free ends)
Analysis Configuration
- Number of modes - Start with 20-30 modes, increase if needed
- DOF thresholds - Use 10-15% for initial screening
- Object selection - Focus on critical structural members
- Batch processing - Compare across configurations
Results Interpretation
- Low-frequency modes - Often global bending/heave
- High-frequency modes - Local vibrations, may indicate VIV risk
- Mixed DOF modes - Coupled motions, require careful assessment
- Clustering - Multiple modes at similar frequencies indicate sensitivity