General

The general section can only be used for user element type U1 and is defined by the following properties (to be given by the user in that order):

• cross section area A
• moment of inertia I_{11}
• moment of inertia I_{12}
• moment of inertia I_{22}
• Timoshenko shear coefficient k

Furthermore, the specification of the 1-direction (cf. third line in the *BEAM SECTION definition) is REQUIRED for this type of section. Internally, the properties are stored in the prop-array in the following order:

• cross section area A
• moment of inertia I_{11}
• moment of inertia I_{12}
• moment of inertia I_{22}
• Timoshenko shear coefficient k
• global x-coordinate of a unit vector in 1-direction
• global y-coordinate of a unit vector in 1-direction
• global z-coordinate of a unit vector in 1-direction
• offset1
• offset2

In the present implementation of the U1-type element I_{12}, offset1 and offset2 have to be zero.