Warp & Mass Tab

Use the Warp & Mass tab on the Beam Section Definition dialog box to define additional beam values for NASTRAN. This tab is active only in FEM mode, and contains the following items:

• Warp Coefficient—Enter the warp coefficient, which is expressed as:

units of length 6

Use this field for tapered beams only. NASTRAN normally calculates beam sections using equations that assume a beam section is uniform. If you enter a warp coefficient, NASTRAN applies that coefficient as a corrective factor for torsion so that the equations accurately interpret the beam section.

• Non-Structural Mass per Unit Length—Enter the non-structural mass per unit length. A non-structural mass is a mass that responds to gravity, but does not strengthen the structure—for example, fluid running in a pipe that you have modeled as a beam. Non-structural masses can have different moments of inertia and gravitational centers than the beam you are creating.

• Non-Structural Mass Moment per Unit Length—Enter the non-structural mass moment of inertia per unit length.

• Coordinates of Non-Structural Mass C.G.

◦ Y—Specify the Y coordinates of the non-structural mass center of gravity.

◦ Z—Specify the Z coordinates of the non-structural mass center of gravity.