/TH/ACCEL
Block Format Keyword Describes the time history for accelerometers.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
/TH/ACCEL/thgroup_ID | |||||||||
thgroup_name | |||||||||
var_ID1 | var_ID2 | var_ID3 | var_ID4 | var_ID5 | var_ID6 | var_ID7 | var_ID8 | var_ID9 | var_ID10 |
Obj_ID1 | Obj_ID2 | Obj_ID3 | Obj_ID4 | Obj_ID5 | Obj_ID6 | Obj_ID7 | Obj_ID8 | Obj_ID9 | Obj_ID10 |
Definition
Field | Contents | SI Unit Example |
---|---|---|
thgroup_ID | TH
group identifier (Integer, maximum 10 digits) |
|
thgroup_name | TH
group name (Character, maximum 100 characters) |
|
var_ID1, ...n | Variables saved for
TH (see table below) (Character, maximum 8 characters) |
|
Obj_ID1, ...n | Identifiers of the objects
to be saved (Integer) |
TH Output Keyword & Variables
Keyword | Object Saved | Variables |
---|---|---|
ACCEL | Accelerometer | AX, AY, AZ, WX, WY, WZ |
Available Variables - Part 2
Keyword | Variable Group | Saved TH Variables |
---|---|---|
ACCEL | DEF | AX, AY, AZ |
W | WX, WY, WZ |
Output for Accelerometer
- AX: acceleration in direction X
- AY: acceleration in direction Y
- AZ: acceleration in direction Z
- WX: integral of acceleration in direction X
- WY: integral of acceleration in direction Y
- WZ: integral of acceleration in direction Z
Let = the nodal acceleration vector expressed in the global skew system, the nodal acceleration vector projected onto the moving skew.
Let = the nodal velocity vector expressed in the global skew system, the nodal velocity vector projected onto the moving skew.
Let = the orientation matrix of the skew at time , so that:(1) (2) Derivating versus time leads to:(3) This shows that derivating the nodal velocity projected onto the moving skew, does not give an equivalent result to the nodal acceleration projected onto the moving skew, .
The vector WX, WY, and WZ available for output in the accelerometer is:(4) Derivating this output will give a value of nodal acceleration projected onto the moving skew, the integration-derivation acting as another filter other than the 4-pole Butterworth, which is used in the accelerometer and computes the filtered accelerations AX, AY, and AZ.
Comments
- Available outputs are listed in the
two tables above.
In the first table, TH-variables are listed. If a TH-variable is requested, this variable is written.
In the second table, variable groups are listed. If a variable group is requested, all the associated TH-variables are written at once.