ABAQUS 关键字 BEAM ADDED INERTIA英

*BEAM ADDED INERTIA

Define additional beam inertia.

This option is used in conjunction with the *BEAM SECTION or *BEAM GENERAL SECTION option to define additional mass and rotary inertia per unit length in shear flexible Timoshenko beam elements. This option is also used to define mass proportional damping (for direct-integration dynamic analysis) and in ABAQUS/Standard composite damping (for modal dynamic analysis) associated with the added inertia.

Products: ABAQUS/Standard ABAQUS/Explicit

Type: Model data

Level: Part Part Instance Assembly

References:

•“Choosing a beam element,” Section 23.3.3 of the ABAQUS Analysis User's Manual

•“Beam section behavior,” Section 23.3.5 of the ABAQUS Analysis User's Manual

Optional parameters:

ALPHA

Set this parameter equal to the factor to create inertia proportional damping for added

inertia associated with this option when used in direct-integration dynamics. This value is

ignored in modal dynamics. The default is ALPHA=0.0. (Units of T–1.)

COMPOSITE

This parameter applies only to ABAQUS/Standard analyses.

Set this parameter equal to the fraction of critical damping to be used with the beam elements when calculating composite damping factors for the modes when used in modal dynamics. This value is ignored in direct-integration dynamics. The default is COMPOSITE=0.0.

Data line to define additional beam inertia:

First line:

1.Mass per unit length.

1.Local 1-coordinate of the center of mass within the beam cross-section, .

1.Local 2-coordinate of the center of mass within the beam cross-section, .

1.Orientation angle for the first axis of the oriented system relative to the first beam cross-

sectional direction in which the rotary inertia is given, (in degrees). Only relevant for

beams in space; otherwise, leave blank.

1.Rotary inertia around the center of mass about the 1-axis in the local inertia system, .

1.Rotary inertia around the center of mass about the 2-axis in the local inertia system, . Only

relevant for beams in space; otherwise, leave blank.

1.Product of inertia, . Only relevant for beams in space; otherwise, leave blank.

The rotary inertia should be given in units of ML. ABAQUS does not use any specific physical units, so the user's choice must be consistent.

Repeat this set of data lines as often as necessary to define the additional beam inertia.