Description
The tower data file defines the inertial and geometric properties of a cylindrical tower structure. For CRAFTS models with body flexibility enabled, the tower data file also includes structural stiffness and damping.
The tower is modeled as a discretized cylindrical structure composed of Multibody Beam Elements (MBEs). Each MBE is composed of two lumped rigid bodies. For CRAFTS models with body flexibility enabled, the rigid bodies are connected via a 3-degree-of-freedom revolute joint for bending and torsion. Otherwise, the bodies are rigidly connected.
An optional wiring data file can also be generated that includes the inertial effects of wires within the tower cylinder.
Parameters
| Name | Description | Value | Unit |
|---|---|---|---|
Rho* |
Density of the tower material. | Real scalar | [kg/m³] |
E* |
Elastic modulus of the tower material. | Real scalar | [Pa] |
G* |
Shear modulus of the tower material. | Real scalar | [Pa] |
Number of MBEs* |
Number of elements used to discretize the tower. A value of N elements requires the elevation, outer diameter, and thickness to be defined at N + 1 locations across the tower. |
Integer scalar | [-] |
Wiring Mass |
Total mass of the wiring system. | Real scalar | [kg] |
Beta* |
Stiffness-proportional damping parameter. | Real scalar, 1×3 array, or NumMBEs × 3 matrix | [s] |
Wiring CoM |
Center of mass of wiring relative to tower base. | Real 1×3 array | [m] |
Elevation* |
Elevation values along the tower cylinder axis. | Real 1 × (NumMBEs + 1) array | [m] |
Outer Diameter* |
Outer diameter at each elevation point. | Real 1 × (NumMBEs + 1) array | [m] |
Thickness* |
Wall thickness at each elevation point. | Real 1 × (NumMBEs + 1) array | [m] |
Notes
The parameters Wiring Mass and Wiring CoM are optional and can be omitted if wires are not desired in the tower model.
The diagram depicts a tower composed of 4 MBEs. Elevation, outer diameter, and wall thickness are specified at 5 locations along the tower height.
