Pressure

PROPERTY LOAD PRESSURE [load_name] [loadcase_no] part_name/ALL args

Argument Meaning

load_name FEMGEN load name.

loadcase_no FEMGEN loadcase number.

part_name Geometry containing element faces.

arg1 Pressure at point name1.

arg2 Degree of Freedom Indicator (0).

arg3 Point name1. (optional)

arg4 Point name2. (optional)

arg5 Pressure at point name2. (optional)

Notes:

1.

Valid part types are shell faces, brick faces.

2.

The degree of freedom indicator should be set to zero (normal) for all part types.

3.

Arguments 3, 4, and 5 are optional and may be used to specify a linear variation of pressure from arg1 at name1 to arg5 at name2

4.

Local Coordinate System attached to Pressure load is not supported.

Example FEMGEN Command:

PROPERTY LOAD PRESSURE L2 100 0

Pressure waves:

When sets named 'PTIM****' (where * can be any printable character) are present, the pressure load defines a pressure wave. The pressure load is applied to a surface defining the location of the source pressure and sets named 'PTIM****' contain the surfaces that are going to be subjected to the resulting pressure wave, see figure 9.1. The interface program calculates the time at which pressure arrives at those surfaces.

• The pressure load has to be applied to a planar surface. If the loaded surface is not planar a warning message is issued and the pressure load is not considered as a pressure wave.
• The pressure arrival time is calculated by using the maximum speed of sound through all materials as defined in Appendix A.
• Pressure cards with pressure arrival time can be output only for the small format of DYNA3D input file (refer to DYNA3D manual). The input file format can be defined by using environment variable FG_PRE_FOR and it should be set to SMALL.

  

Figure 9.1: Example Pressure Wave Definition