Beam Attributes: Cable Free Length

Description

Assigns a cable free length to selected beam elements of type cable.

The free length is the unstretched, or stress-free, length of the cable.

If the cable free length is greater than the chord length of the element, the cable droops as a catenary under the action of gravity or other translational accelerations.

If the cable free length is shorter than the chord length, the cable is pre-loaded in tension (i.e., pre-strained).

If a cable free length attribute is not assigned, the chord length is used as the cable free length.

Cable free length attributes are independent of load and freedom cases. However, thermal expansion and pre-strain attributes, which are load case dependent, can be used to modify a cable free length. This feature of the attribute is useful to produce effects like cable lengthening and/or shortening in a geometric nonlinear analysis.

The mass of a cable is equal to the material density times the cable volume. The cable volume is calculated as the product of the cross section area and the cable free length. In the case where the cable free length is modified during the analysis, an option in the cable property data is used to set how the cable mass is to be updated when the free length changes (see Beam Properties: Cable).

Dialog

Value

The free length of cable.

Cable free length is always positive.

Common Controls

• Components
• Equation Editor
• Retrieve from model
• Keep selection
• Scale / Add / Delete / Apply

Units

Length (e.g., m, in).

See Also

• Global: Initial Cable Droop
• Beam Properties: Cable