*SetBeam() - circular cross section
Sets the properties of a beam circular cross section.
Syntax
*SetBeam(beam_name, CIRCULAR, len|AUTO_LENGTH,
                                        E,      G,
                                        OD,     ID,    AS,
                                        CRATIO, ratio)
    Arguments
- beam_name
 - The variable name of an existing beam.
 - CIRCULAR
 - This argument indicates the cross section of the beam is circular.
 - len
 - len specifies the undeformed length of the beam.
 - AUTO_LENGTH
 - AUTO_LENGTH indicates that the undeformed length of the beam is calculated automatically using the end points of the beam.
 - E
 - The Young's modulus of elasticity.
 - G
 - The shear modulus of elasticity.
 - OD
 - The outer diameter of the cross section.
 - ID
 - The inner diameter of the cross section.
 - AS
 - The correction factor for shear deflection.
 - CRATIO
 - This argument indicates the structural damping matrix is the ratio of the stiffness matrix.
 - ratio
 - Ratio for calculating the damping matrix.
 
Example
*Beam( bm_1, "Beam 1", b_dummy1, b_dummy2, 
 p_beam1, p_beam2)
 
*SetBeam(bm_1, CIRCULAR, 1000, 
 2.0e+05, 7.6e+04, 10, 
 1, 0, CRATIO, 0.01)