Beam Attributes: Principal Distributed Moment

Description

Assigns distributed moments about the principal axes to selected beam elements.

The distribution can be constant, linear, triangular or trapezoidal. It may act over the whole or partial length of the beam, around any of the three beam principal axis directions .

A positive distributed moment acts in the right-hand sense around the selected principal axis.

Principal distributed moment attributes are load case dependent.

Dialog

P1 / P2 / PA / PB

Value of distributed moment at specified points along the beam. The moment is linearly interpolated between these points.

P1

Distributed moment value at end 1.
P2

Distributed moment value at end 2.
PA

Distributed moment value at position a.
PB

Distributed moment value at position b.

a / b

Distance of points PA and PB from each end, specified as a fraction of the element's length.

Non-dimensional values in the range 0 to 1.

a

Relative distance from end 1 of the beam. Determines the position of PA. At end 1, a=0.0.
b

Relative distance from end 2 of the beam. Determines the position of PB. At end 2, b=0.0.

Dir 1 / 2 / 1-2

The principal axes about which the distributed moment acts. See Beam Elements: Local and Principal Axes.

Dir 1-2 defines the load direction at a specified angle in the principal 1-2 plane.

θ-1

The angle that defines the load direction, measured from the principal 1 if Dir 1-2 is selected.

Swap

Swaps the values of a and b, P1 and P2, PA and PB.

Assigns an ID to the attribute.

By using different IDs, multiple moments can be applied to the same element for the same load case.

IDs are positive integers between 1 and 192.

Distribution Type

The distribution type includes constant, linear, triangular and trapezoidal over the whole or partial length of the element.

The appropriate text boxes will be active depending on the moment distribution selected.

Common Controls

Units

Components: Force×Length/Length (e.g., N.m/m, lbf.in/in).

Relative Distances: Dimensionless.