WOLFRAM SYSTEMMODELER

Spring

Linear translational spring with optional mass

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Mechanics.MultiBody.Forces.Spring"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Linear spring acting as line force between frame_a and frame_b. A force f is exerted on the origin of frame_b and with opposite sign on the origin of frame_a along the line from the origin of frame_a to the origin of frame_b according to the equation:

   f = c*(s - s_unstretched);

where "c" and "s_unstretched" are parameters and "s" is the distance between the origin of frame_a and the origin of frame_b.

Optionally, the mass of the spring is taken into account by a point mass located on the line between frame_a and frame_b (default: middle of the line). If the spring mass is zero, the additional equations to handle the mass are removed.

In the following figure a typical animation of the spring is shown. The blue sphere in the middle of the spring characterizes the location of the point mass.

model Examples.Elementary.SpringWithMass

Parameters (10)

animation

Value: true

Type: Boolean

Description: = true, if animation shall be enabled

showMass

Value: true

Type: Boolean

Description: = true, if point mass shall be visualized as sphere if animation=true and m>0

c

Value:

Type: TranslationalSpringConstant (N/m)

Description: Spring constant

s_unstretched

Value: 0

Type: Length (m)

Description: Unstretched spring length

m

Value: 0

Type: Mass (kg)

Description: Spring mass located on the connection line between the origin of frame_a and the origin of frame_b

lengthFraction

Value: 0.5

Type: Real

Description: Location of spring mass with respect to frame_a as a fraction of the distance from frame_a to frame_b (=0: at frame_a; =1: at frame_b)

numberOfWindings

Value: 5

Type: Integer

Description: Number of spring windings

s_small

Value: 1e-10

Type: Distance (m)

Description: Prevent zero-division if distance between frame_a and frame_b is zero

fixedRotationAtFrame_a

Value: false

Type: Boolean

Description: =true, if rotation frame_a.R is fixed (to directly connect line forces)

fixedRotationAtFrame_b

Value: false

Type: Boolean

Description: =true, if rotation frame_b.R is fixed (to directly connect line forces)

Inputs (6)

width

Default Value: world.defaultForceWidth

Type: Distance (m)

Description: Width of spring

coilWidth

Default Value: width / 10

Type: Distance (m)

Description: Width of spring coil

color

Default Value: Modelica.Mechanics.MultiBody.Types.Defaults.SpringColor

Type: Color

Description: Color of spring

specularCoefficient

Default Value: world.defaultSpecularCoefficient

Type: SpecularCoefficient

Description: Reflection of ambient light (= 0: light is completely absorbed)

massDiameter

Default Value: max(0, (width - 2 * coilWidth) * 0.9)

Type: Diameter (m)

Description: Diameter of mass point sphere

massColor

Default Value: Modelica.Mechanics.MultiBody.Types.Defaults.BodyColor

Type: Color

Description: Color of mass point

Connectors (2)

frame_a

Type: Frame_a

Description: Coordinate system a fixed to the component with one cut-force and cut-torque

frame_b

Type: Frame_b

Description: Coordinate system b fixed to the component with one cut-force and cut-torque

Components (3)

world

Type: World

lineForce

Type: LineForceWithMass

spring

Type: Spring

Used in Examples (13)

FreeBody

Modelica.Mechanics.MultiBody.Examples.Elementary

Free flying body attached by two springs to environment

InitSpringConstant

Modelica.Mechanics.MultiBody.Examples.Elementary

Determine spring constant such that system is in steady state at given position

PendulumWithSpringDamper

Modelica.Mechanics.MultiBody.Examples.Elementary

Simple spring/damper/mass system

PointGravityWithPointMasses

Modelica.Mechanics.MultiBody.Examples.Elementary

Two point masses in a point gravity field (rotation of bodies is neglected)

SpringDamperSystem

Modelica.Mechanics.MultiBody.Examples.Elementary

Simple spring/damper/mass system

SpringMassSystem

Modelica.Mechanics.MultiBody.Examples.Elementary

Mass attached with a spring to the world frame

SpringWithMass

Modelica.Mechanics.MultiBody.Examples.Elementary

Point mass hanging on a spring

ThreeSprings

Modelica.Mechanics.MultiBody.Examples.Elementary

3-dim. springs in series and parallel connection

HeatLosses

Modelica.Mechanics.MultiBody.Examples.Elementary

Demonstrate the modeling of heat losses

PrismaticConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and two prismatic joints or constrained to environment

RevoluteConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and revolute joint or constrained to environment

SphericalConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and spherical joint or constrained to environment

UniversalConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and universal joint or constrained to environment