/PROP/TYPE12 (SPR

Block Format Keyword

/PROP/TYEP12 - Pulley Spring Property Set

Description

The pulley spring property set (with one translational DOF) is used to model a pulley.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/PROP/TYPE12/prop_ID/unit_ID or /PROP/SPR_PUL/prop_ID/unit_ID
prop_title
Mass					sens_ID	Isflag	Ileng	Fric
K1		C1		A1		B1		D1
fct_ID11	H1	fct_ID21		fct_ID41
F1		E1		Ascale1		Hscale1
fct_IDfr		Yscale_F		Xscale_F

Field	Contents	SI Unit Example
prop_ID	Property identifier (Integer, maximum 10 digits)
unit_ID	Optional unit identifier (Integer, maximum 10 digits)
prop_title	Property title (Character, maximum 100 characters)
Mass	Mass (Real)
sens_ID	Sensor identifier (Integer)
Isflag	Sensor flag. See Comments 5 and 6. (Integer) =0: spring element activated =1: spring element deactivated =2: spring element activated or deactivated
Ileng	Input per unit length flag (Integer) = 0: See Comment 2 = 1: See Comment 3
Fric	Coulomb friction (Comment 8) (Real)
K1	Stiffness (Real)
C1	Damping (Real)
A1	Coefficient for strain rate effect (homogeneous to a force) Default = 1.0 (Real)
B1	Logarithmic coefficient for strain rate effect (homogeneous to a force) (Real)
D1	Scale coefficients for elongation velocity Default = 1.0 (Real)
fct_ID11	Function identifier defining (Integer) = 0: linear spring
H1	Hardening flag (Integer) = 0: Nonlinear elastic spring = 1: Nonlinear elastic plastic spring = 2: Nonlinear elasto-plastic spring with decoupled hardening in tension and compression = 6: Nonlinear elasto-plastic spring with isotropic hardening and nonlinear unloading = 7: Nonlinear spring with elastic hysteresis
fct_ID21	Function identifier defining (Integer)
fct_ID41	Function identifier defining (Integer)
	Negative failure displacement Default = -1030 (Real)
	Positive failure displacement Default = 1030 (Real)
F1	Scale factor for (abscissa of functions) (Real)
E1	Coefficient for strain rate effect (homogeneous to a force) (Real)
Ascale1	Scale factor for (abscissa of functions) (Real)
Hscale1	Coefficient for fct_ID41 (homogeneous to a force) Default = 1 (Real)
fct_IDfr	Function identifier defining scaling of friction coefficient Fric as function of force difference between left and right arms of the pulley. (Integer)
Yscale_F	Ordinate scale for function fct_IDfr Default = 1.0 (Real)
Xscale_F	Abscissa scale for function fct_IDfr Default = 0.0 (Real)

1.	is the difference between the current length and the initial length of the spring element.

2.	In case of Ileng =0 (flag Ileng is defined in Line 3), the force in the spring is computed as:

Linear spring:

Nonlinear spring:

with

linear_spring

Linear spring

nonlinear_spring_0

Nonlinear elastic spring, H1=0

nonlinear_spring_1

Nonlinear elastic plastic spring, H1=1

nonlinear_spring_2

Nonlinear elasto-plastic spring with decoupled hardening in tension and compression, H1=2

nonlinear_spring_6

Nonlinear elasto-plastic spring with isotropic hardening and nonlinear unloading, H1=6

nonlinear_spring_7

Nonlinear spring with elastic hystersis, H1=7

3.	If Ileng = 1, all input are per unit length:

•	Spring mass = Spring stiffness = Spring damping = Spring inertia =

Where, l0 is the spring reference length.

•	The value of force in the spring is computed as:

- Linear spring:

- Nonlinear spring:

Where, is the engineering strain:

- Force functions are given versus engineering strain and engineering strain rate.

- Failure criteria are defined with respect to strain. Input of negative/positive failure limit should be related to initial length l0

4.	If (resp ) is 0, no failure in the direction. The must be negative. For linear springs, and are null functions and A1, B1 and E1 are not taken into account.

5.	Spring is activated and/or deactivated by sensor:

•	If sens_ID ≠ 0 and Isflag = 0, the spring element is activated by the sens_ID.

•	If sens_ID ≠ 0 and Isflag = 1, the spring element is deactivated by the sens_ID.

•	If sens_ID ≠ 0 and Isflag = 2, then:

•	The spring is activated and/or, deactivated by sens_ID. (if sensor is ON, spring is ON; if sensor is OFF, spring is OFF).

•	The spring reference length (l0) is the distance between spring node N1 and N2 at the time of the sensor’s activation.

6.	If a sensor is used for activating or deactivating a spring, the reference length of the spring at sensor activation (or deactivation) is equal to the nodal distance at time =0; except if sensor flag is equal to 2.

7.	3 Node Spring

clip0120

8.	If fct_IDfr and Fric = 0 (no friction), then .

9.	If fct_IDfr = 0 and Fric > 0, then constant Coulomb friction coefficient used:

If fct_IDfr > 0, then variable friction is calculated as a function on relative force between two pulley branches:

Where, is the angle (radians unit) and ffr is the function of fct_IDfr.

/PROP/TYPE12 (SPR_PUL)

/PROP/TYPE12 (SPR_PUL)

/PROP/TYPE12 (SPR_PUL)