I'll search for tower height information in the project files.

The tower height is 87.6 m for this NREL 5MW reference wind turbine model.

This is defined in the structural main definition file (NREL5MW_Main.str) where it specifies:

• TWRHEIGHT = 87.6 m - the height of the tower

The tower is discretized at multiple normalized heights (0%, 10%, 20%, ..., 100%) for structural analysis purposes, as shown in the output offsets (TWR_0.00 through TWR_1.00).

I'll help you increase the tower thickness by 5%. Let me first examine the tower structural file to see the current thickness definitions.

Now I need to understand how tower thickness relates to the structural properties. Let me check the skill details to better understand the scaling approach.

Perfect. Now I understand the tower structure. For a circular tower with thin-walled section, a 5% increase in wall thickness scales the stiffness properties (EIx, EIy, EA, GJ, GA) by approximately 5%, but the diameter and other geometric parameters remain unchanged.

Let me calculate the scaling and apply it:

Done! I've increased the tower thickness by 5% by scaling all the stiffness properties:

What changed:

• EIx, EIy (bending stiffness): scaled by 1.05
• EA (axial stiffness): scaled by 1.05
• GJ (torsional stiffness): scaled by 1.05
• GA (shear stiffness): scaled by 1.05

What stayed the same:

• Diameter (DIA) — kept at original values
• All geometric center offsets (XCM, YCM, XCE, YCE, XCS, YCS)
• Shear factors (KSX, KSY) and radii of gyration (RGX, RGY)
• Structural pitch

This is the correct approach for thin-walled circular tubes like wind turbine towers, where a 5% wall thickness increase translates to approximately 5% stiffness increase across all bending and axial modes. The tower will be stiffer and will have higher natural frequencies as a result.