/LOAD/PRESSURE

Block Format Keyword Defines pressure load on a surface for 3D surface.

Note: This pressure load can be used only for 3D analysis.

Format

(1)	(2)	(3)	(4)	(5)	(6)
/LOAD/PRESSURE/`pload_ID`/`unit_ID`
`pload_title`
`surf_ID`	`Iload`	`sens_ID`	`Inorm`	`Dir`	`Skew_ID`
`fct_ID`_T		`Ascale`_x		`Fscale`_y

Add the line for each contact interface (up to 5)

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
`Inter_ID`_i		`Gap_shift`

Definition

Field	Contents	SI Unit Example
`pload_ID`	Pressure load block identifier. (Integer, maximum 10 digits)
`unit_ID`	(Optional) Unit identifier. (Integer, maximum 10 digits)
`pload_title`	Pressure load block title. (Character, maximum 100 characters)
`surf_ID`	Surface identifier. (Integer)
`Iload`	Load pressure behavior. = 1(Default) Pressure is applied when there is no contact. = 2 Pressure is applied when there is contact. (Integer)
`sens_ID`	Sensor identifier. ≠ 0 Pressure load is applied after sensor activation (the time function is shifted in time). (Integer)
`Inorm`	Pressure direction applied: = 1 (Default) Along the segment normal direction. = 2 On the defined direction `Dir`. = 3 On the defined direction `Dir` and scaled by the segment normal direction. (Integer)
`Dir`	Direction where the pressure is applied (read only for `Inorm`=2,3). X X direction in local or global coordinate system. Y Y direction in local or global coordinate system. Z Z direction in local or global coordinate system. (Integer)
`Skew_ID`	Local coordinate system identifier for the direction where the pressure is applied (read only for `Inorm`=2,3). = 0 Global coordinate system is used. (Integer)
`fct_ID`_T	Time function identifier. (Integer)
`Ascale`_x	Abscissa (Time) scale factor. Default = 1.0 (Real)
`Fscale`_y	Ordinate scale factor. Default = 1.0 (Real)
`Inter_ID`_i	Contact interfaces identifier to activate the pressure loading. Up to 5 interfaces can be defined. (Integer)
`Gap_shift`	Gap shift for the contact detection. Default = 0 (Real)

Comments

The pressure direction is defined as:
- With Inorm=1, positive pressure acts in segment normal direction $n = N_{1} N_{3} \times N_{2} N_{4}$ .
  With $N_{1}$ , $N_{2}$ , $N_{3}$ , and $N_{4}$ being the nodes of the segment in the surface definition.
- With Inorm=2, pressure is applied along the defined direction.
- With Inorm=3, pressure is applied along the defined direction and scaled by the segment normal direction. There is no more pressure for the segment normal direction perpendicular to the defined direction.
The Ascale_x and Fscale_y are used to scale the abscissa (time) and ordinate (pressure).
The actual pressure function value is calculated as:(1)
$F (t) = F s c a l e_{y} \cdot f_{T} \cdot (\frac{t}{A s c a l e_{x}})$

Where, $f_{T}$ is the function of fct_ID_T.
The contact is detected when the distance between the main and the secondary surface is equal to or less than the contact gap + Gap_shift.
With Iload=0, pressure will be applied only on the facets defined in surf_ID, which are not in contact interface(s) Inter_ID_i.

Figure 1.
With Iload=1, the pressure will be applied only on the facets defined in surf_ID which are in contact interface(s) Inter_ID_i.

Figure 2.
Pressure load is canceled when all the elements associated to the segment are deleted.