Model Preparation (+2)

Model Preparation

1. Ensure static convergence before modal analysis
2. Use appropriate segment lengths for accurate mode shapes
3. Include all relevant objects in the analysis
4. Consider boundary conditions (fixed vs. free ends)

Analysis Configuration

1. Number of modes - Start with 20-30 modes, increase if needed
2. DOF thresholds - Use 10-15% for initial screening
3. Object selection - Focus on critical structural members
4. Batch processing - Compare across configurations

Results Interpretation

1. Low-frequency modes - Often global bending/heave
2. High-frequency modes - Local vibrations, may indicate VIV risk
3. Mixed DOF modes - Coupled motions, require careful assessment
4. Clustering - Multiple modes at similar frequencies indicate sensitivity