**gravity

Description

The gravity condition applies a body force due to uniform acceleration such as gravity.

To apply a gravitational force, it is required to give the volumetric mass for the material in the material file. This is specified with the ***coefficient command.

Syntax

The gravitational BC is specified with the following syntax:

**gravity elset_name dir value [table]

elset_name

Character name for the pre-defined element set where the gravitational acceleration is applied.

dir

Direction of the gravitational force (d1, d2 or d3). Axisymmetric 2D problems require that the direction be d2. Plane 2D geometries require that the direction is d1 or d2.

value

Real base value scaling the current table magnitude to determine the acceleration magnitude.

table

Character name for a valid loading table or tables which will describe the acceleration in time.

Units required depend of course on the consistency of units within the problem. For example, if the dimensional unit is millimeter, the forces are given in Newtons, and the gravitational acceleration is in mm/sec/sec, the volumetric mass must be in tons (metric)mm/mm/mm.

Example

**gravity
    str d2 -20.0 tab1