Transient Response Dynamic Load, Form 2
Description: Defines a time-dependent dynamic load or enforced motion of the form
for use in transient response analysis.
Format:
Example:
Field
|
Definition
|
Type
|
Default
|
SID
|
Set identification number.
|
Integer > 0
|
Required
|
EXCITEID
|
DAREA or
SPCD entry set identification number that defines
A.
|
Integer > 0
|
Required
|
DELAY
|
DELAY set identification number that defines
.
|
Integer > 0 or blank
|
|
TYPE
|
Defines the nature of the dynamic excitation. See Remark 2.
|
0 ≤ Integer ≤ 3 or character
|
0
|
T1
|
Time constant.
|
Real ≥ 0.0
|
Required
|
T2
|
Time constant.
|
Real; T2 > T1
|
Required
|
F
|
Frequency in cycles per unit time.
|
Real ≥ 0.0
|
0.0
|
P
|
Phase angles in degrees.
|
Real
|
0.0
|
C
|
Exponential coefficient.
|
Real
|
0.0
|
B
|
Growth coefficient.
|
Real
|
0.0
|
Remarks:
- Dynamic load sets must be selected with the Case Control command
DLOAD = SID.
- The nature of the dynamic excitation is defined in the following table:
TYPE
|
Type of Dynamic Excitation
|
0, L, or LOAD
|
Applied load (force or moment) (default)
|
1, D, or DISP
|
Enforced displacement using large mass or SPCD
|
2, V, or VELO
|
Enforced velocity using large mass or SPCD
|
3, A, or ACCE
|
Enforced acceleration using large mass or SPCD
|
- The TYPE field determines the manner in which the EXCITEID field is used as described below:
- Excitation specified by TYPE is an applied load
- If there
is no
LOADSET request in the Case Control, then EXCITEID may directly reference
DAREA, static, and thermal load set entries.
- If there
is a LOADSET request in the Case Control, then the model will reference static and thermal load set entries specified by the LID or TID field in the selected
LSEQ entries corresponding to the EXCITEID.
- Excitation specified by TYPE is an enforced motion
- If there
is no LOADSET request in the Case Control, then EXCITEID will reference
SPCD entries. If these entries indicate null enforced motion, Autodesk Nastran will then assume that the excitation is enforced motion using large mass and will reference DAREA and static and thermal load set entries just as in the case of applied load excitation.
- If there
is a LOADSET request in Case Control, then the model will reference SPCD entries specified by the LID field in the selected LSEQ entries corresponding to the EXCITEID. If these entries indicate null enforced motion, Autodesk Nastran will then assume that the excitation is enforced motion using large mass and will reference static and thermal load set entries corresponding to the DAREA entry in the selected LSEQ entries, just as in the case of applied load excitation.
- EXCITEID may reference sets containing
QHBDY,
QBDYi, and
QVOL entries in heat transfer analysis.
- If DELAY is blank or zero,
will be set to zero.
- The continuation entry is optional.