*SetTorsionSpring() - symmetric torsion spring pair

Sets the properties of a symmetric torsion spring pair.

Syntax

*SetTorsionSpring(spr_name, LEFT|RIGHT, 
                                      TYPE_k, TOKEN_k, 
                                      TYPE_c, TOKEN_c, 
                                      f, l)

Token

If you select this TYPE, use this TOKEN
LIN
Enter a value for: k and c
Token: Value
CRV
Use a Curve to represent the torsion spring behavior. See Comments.
Token: curve_name,

AKIMA|CUBIC|LINEAR|

QUINTIC,

`indep_variable`

SPL3D
Use a Spline3D to represent the torsion spring behavior. See Comments.
Token: spl3d_name,

AKIMA|CUBIC|LINEAR|QUINTIC

'indep_var1',

'indep_var2'

EXPR
Enter a solver expression that represents the torsion spring behavior.
Token: `expression`

Arguments

spr_name
The variable name of an existing torsion spring pair.
Data type: varname
LEFT RIGHT
If LEFT is specified, the properties are assigned to the left spring, and the right spring properties are made symmetric to the left spring.
If RIGHT is specified, the properties are assigned to the right spring, and the left spring properties are made symmetric to the right spring.
k
The stiffness coefficient of the torsion spring.
Data type: real
c
The damping coefficient of the torsion spring.
Data type: real
f
The load on the torsion spring when it has a particular angle.
Data type: real
l
The angle of the torsion spring when it has a particular load.
Data type: real
curve_name, AKIMA|CUBIC|LINEAR|QUINTIC, `indep_variable`
When using curve data, a curve, an interpolation method, and an independent variable must be specified, where curve_name is the variable name of an existing curve that represents the force characteristic, the interpolation method can be set to AKIMA, CUBIC, LINEAR, or QUINTIC. The indep_variable is the solver expression representing the independent variable along which the force curve is characterized.
spl3d name, AKIMA|CUBIC|LINEAR| QUINTIC, 'indep_var1', 'indep_var2'
When using spline3d, a Spline3D entity, an interpolation method, and two independent variables must be specified, where spl3d_name is the variable name of an existing Spline3D entity that would represent the force v/s two independent variables. The interpolation method can be set to AKIMA, CUBIC, LINEAR, or QUINTIC. indep_var1 is the solver expression for the first independent variable. indep_var2 is the solver expression that represents the second independent variable.
`expression`
A solver expression for the torsion spring.

Example

*PointPair(p_bar_mnt_left,  "Bar mnt left")
*PointPair(p_bar_mnt_right, "Bar mnt right")
*BodyPair(b_bar_left,	    "Bar left", p_bar_left_cg)
*BodyPair(b_bar_right,	    "Bar right", p_bar_right_cg)
*TorsionSpringPair(tspr,	"Torsion spring",	
					b_bar_left,
                  	      b_bar_right,
                              p_bar_mnt_left,
                              p_bar_mnt_right)
*SetTorsionSpring(spring_uca, LEFT, 
					      1.000e+02,   0.000e+00, 
					      0.000e+00,	 3.500e+02)

Context

*BeginMdl()

*DefineAnalysis()

*DefineSystem()

Comments

Nonlinear properties for stiffness or damping cannot be specified for a symmetric pair.

To specify non-linear properties for the torsion spring in any direction, a solver expression, curve data, or spline 3D data can be used. When using solver expressions, Templex syntax is used and all variables are enclosed in braces {} and the rest is treated as literal.

The QUINTIC interpolation method is supported for MotionSolve only.