TLOAD2

Bulk Data Entry Defines a time-dependent dynamic excitation or enforced motion.

Description

Defines a time-dependent dynamic excitation or enforced motion of the form:(1)

f (t) = {\begin{array}{l} 0 & for & t < (T_{1} + τ) or t > (T_{2} + τ) \\ A {\tilde{t}}^{B} e^{C \ddot{t}} cos (2 π \bar{f} \tilde{t} + ϕ) & for & (T_{1} + τ) \leq t \leq (T_{2} + τ) \end{array}

For use in a transient response analysis, where $\tilde{t} = t - T_{1} - τ$ and $T_{2} > T_{1}$ . It can also be used to specify the user-defined static loading curve for Nonlinear Static Analysis.

Where,

$f (t)$ is the time-dependent dynamic load or enforced motion, multiplier for transient heat transfer convection coefficient or user-defined loading curve.

$A$ defines the amplitude of the dynamic excitation in transient response analysis, or base-load in Nonlinear Static Analysis and is referenced by the EXCITEID field.

$τ$ is the time delay defined in the DELAY field.

$T_{1}$ and $T_{2}$ are time constants defined in the T1 and T2 fields.

B, C, $f$ and $φ$ are the growth coefficient, exponential coefficient, frequency and phase angle respectively and are defined in the corresponding B, C, F and P fields.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)
TLOAD2	`SID`	`EXCITEID`	`DELAY`	`TYPE`	`T1`	`T2`	`F`	`P`
	`C`	`B`
	"`EXTN`"	`TSTIME`

Example

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
TLOAD2	4	10			2.1	4.7	12.0
	2.0

Definitions

Field	Contents	SI Unit Example
`SID`	Set identification number. (Integer > 0)
`EXCITEID`	Identification number of the DAREA, SPCD, FORCEx, MOMENTx, PLOADx, RFORCE, QVOL, QBDY1, ACCEL, ACCEL1, ACCEL2, GRAV, TEMP, or TEMPD entry set that defines $A$ . 2 3 (Integer > 0)
`DELAY`	Defines time delay $τ$ . If it is a non-zero integer, it represents the identification number of DELAY Bulk Data Entry that defines $τ$ . If it is real, then it directly defines the value of $τ$ that will be used for all degrees-of-freedom that are excited by this dynamic load entry. If blank or zero, $τ$ will be zero. (Integer ≥ 0, real or blank
`TYPE`	Defines the type of the dynamic excitation. 2 3 Default = 0 (Integer, character or blank)
`T1`	Time constant. (Real ≥ 0.0)
`T2`	Time constant. (Real; `T2` > `T1`)
`F`	Frequency in cycles per unit time. Default = 0.0 (Real ≥ 0.0)
`P`	Phase angle in degrees. Default = 0.0 (Real)
`C`	Exponential coefficient. Default = 0.0 (Real)
`B`	Growth coefficient. Default = 0.0 (Real)
"`EXTN`"	Extended options indicator.
`TSTIME`	String to indicate Total/Subcase time switch. Only supported for Nonlinear subcases. 10 TOT or 0 Uses total time to look up table data for current TLOAD2. SUB or 1 Uses subcase time to look up table data for current TLOAD2. blank Default = TOT

Comments

Dynamic excitation sets must be selected with the Subcase Information command with DLOAD=SID.

The type of dynamic excitation is specified by TYPE (field 5) based on the following table:

TYPE		TYPE of Dynamic Excitation
Integer	Character	TYPE of Dynamic Excitation
0	L, LO, LOA, or LOAD	Applied load (force or moment). (Default)
1	D, DI, DIS, or DISP	Enforced displacement or temperature; `EXCITEID` references SPC/SPCD data.
2	V, VE, VEL, or VELO	Enforced velocity; `EXCITEID` references SPC/SPCD data.
3	A, AC, ACC, or ACCE	Enforced acceleration; `EXCITEID` references SPC/SPCD data.
4	T, TE, TEM, or TEMP	Enforced temperature; `EXCITEID` references TEMP/TEMPD data.

The TYPE also determines the manner in which EXCITEID is used by the program as described below.
- If the type of dynamic excitation specified by TYPE is applied load, the EXCITEID must reference DAREA, FORCEx, MOMENTx, PLOAD, RFORCE, GRAV, QVOL, ACCEL, ACCEL1, ACCEL2 or QBDY1 entries.
- If the type of dynamic excitation specified by TYPE is enforced motion (TYPE=1, 2, or 3), the EXCITEID must reference SPC/SPCD entries.
- If the excitation specified by TYPE is enforced temperature (TYPE=4), the EXCITEID must reference TEMP/TEMPD entries.
- TYPE=1 must be specified if the EXCITEID field references SPCD data used in transient heat transfer analysis to define time-dependent thermal boundary conditions. This also applies when using SPCD to identify a time-dependent heat transfer convection coefficient.
TLOAD1 loads may be combined with TLOAD2 loads only by specification on a DLOAD entry. That is, the SID on a TLOAD1 entry may not be the same as that on a TLOAD2 entry.
SID must be unique for all TLOAD1, TLOAD2, RLOAD1, and RLOAD2 entries.
TLOAD2 entries cannot be used with Fourier analysis.
The continuation entry is optional.
When EXCITEID refers to an SPCD entry, the modal space will be augmented with displacement vector(s) from linear static analysis with unit prescribed displacement at each of the SPCD degrees-of-freedom. EXCITEID cannot reference the LOAD and LOADADD Bulk Data Entries.
The DT and TTERM fields on the NLPARM Bulk Data Entry allow for an alternate method (instead of NINC) to define the loading curve for Nonlinear Static Analysis. The DLOAD Subcase Entry can be used in a NLSTAT subcase to reference TLOAD2 Bulk Data Entry. This allows for the specification of a user-defined loading curve via the TLOAD2 entry.
The TSTIME field is only supported for Nonlinear subcases.
This card is represented as a load collector in HyperMesh.