Grid Area Loads

These are area loads located in space or, more precisely, on a grid surface which is located in space. The grid surface is also used to identify the elements that are considered during the grid load expansion. Refer to Specifying Grid Loading for details.

Grid area loads must be located so as be bounded by a closed polygon of elements.

If the grid surface associated with the load is 2D element type, the grid area load will be transferred as point loads on each of the 2D elements which intersects with the grid area load. Position of the point load is at the centroid of the intersected polygon between the grid area load and the 2D element. Intensity of the point load is also calculated from the intersected grid area load polygon.

Definition

Name

The name is only used as a convenient way of identifying a load. Optional.

Grid Surface

The surface in which the load is located and the surface that defines the elements that attract the load. Note that the load is not necessarily applied in the underlying grid plane axis directions (see Axis, below).

In sculpt: The grid plane is set to the current grid. The grid plane cannot be edited in the dialog.

Load Type

Area loads can either apply to the whole plane, in which case the load boundary is the structure boundary, or to a polygon on the grid surface. If the loaded area is defined by a polygon this can either be a reference to a 2D polyline defined outside the grid loading or a polygon embedded in the load record.

2D Polygon

If the area loads are applied to a reference to a polygon the polygon is defined by reference to a 2D polyline. If a polygon is embedded in the load record it should be of the form ‘(x0,y0), (x1,y1), ... (xn,yn) (unit)’, where the ‘(unit)’ part is optional.

The polyline is defined in grid coordinates (i.e. x and y coordinates in the grid plane) and is assumed to close back to the starting point – it is not necessary to explicitly close the polyline. Note that the vertices are defined by Cartesian x-y coordinates even when the grid plane is cylindrical.

In sculpt: An existing 2D Polyline identical to the current polyline is referenced or the current polyline is saved as a 2D Polyline and referenced. The 2D Polyline cannot be edited in the dialog.

Load Case

This is the load case in which the load applies. The load case gives a way of grouping load effects together.

Axis

The axis in which the load is applied. Setting this to local implies panel local axes.

Direction

The direction of the loading, in the specified axis direction.

Projected

When the load and the structure are not orthogonal the load applied to the structure depends on whether the load is taken as applying to the area of the polygon or the area of the polygon projected on to the structure in the load direction.

Value

The magnitude of the load.