WOLFRAM SYSTEMMODELER

Prismatic

Prismatic joint (1 translational degree-of-freedom, 2 potential states, optional axis flange)

Diagram

Wolfram Language

In[1]:=
Click for copyable input
SystemModel["Modelica.Mechanics.MultiBody.Joints.Prismatic"]
Out[1]:=

Information

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

Joint where frame_b is translated along axis n which is fixed in frame_a. The two frames coincide when the relative distance "s = 0".

Optionally, two additional 1-dimensional mechanical flanges (flange "axis" represents the driving flange and flange "support" represents the bearing) can be enabled via parameter useAxisFlange. The enabled axis flange can be driven with elements of the Modelica.Mechanics.Translational library.

In the "Advanced" menu it can be defined via parameter stateSelect that the relative distance "s" and its derivative shall be definitely used as states by setting stateSelect=StateSelect.always. Default is StateSelect.prefer to use the relative distance and its derivative as preferred states. The states are usually selected automatically. In certain situations, especially when closed kinematic loops are present, it might be slightly more efficient, when using the StateSelect.always setting.

In the following figure the animation of a prismatic joint is shown. The light blue coordinate system is frame_a and the dark blue coordinate system is frame_b of the joint. The black arrow is parameter vector "n" defining the translation axis (here: n = {1,1,0}).

Connectors (4)

frame_a

Type: Frame_a

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

frame_b

Type: Frame_b

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

axis

Type: Flange_a

Description: 1-dim. translational flange that drives the joint

support

Type: Flange_b

Description: 1-dim. translational flange of the drive drive support (assumed to be fixed in the world frame, NOT in the joint)

Parameters (8)

useAxisFlange

Value: false

Type: Boolean

Description: = true, if axis flange is enabled

animation

Value: true

Type: Boolean

Description: = true, if animation shall be enabled

n

Value: {1, 0, 0}

Type: Axis ()

Description: Axis of translation resolved in frame_a (= same as in frame_b)

boxWidthDirection

Value: {0, 1, 0}

Type: Axis ()

Description: Vector in width direction of box, resolved in frame_a

boxWidth

Value: world.defaultJointWidth

Type: Distance (m)

Description: Width of prismatic joint box

boxHeight

Value: boxWidth

Type: Distance (m)

Description: Height of prismatic joint box

stateSelect

Value: StateSelect.prefer

Type: StateSelect

Description: Priority to use distance s and v=der(s) as states

e

Value: Modelica.Math.Vectors.normalizeWithAssert(n)

Type: Real[3] ()

Description: Unit vector in direction of prismatic axis n

Components (5)

world

Type: World

Description:

box

Type: Shape

Description:

fixed

Type: Fixed

Description:

internalAxis

Type: InternalSupport

Description:

constantForce

Type: ConstantForce

Description:

Used in Examples (9)

PendulumWithSpringDamper

Simple spring/damper/mass system

SpringDamperSystem

Simple spring/damper/mass system

SpringMassSystem

Mass attached with a spring to the world frame

Surfaces

Demonstrate the visualization of a sine surface, as well as a torus and a wheel constructed from a surface

Engine1a

Model of one cylinder engine

Engine1b

Model of one cylinder engine with gas force and preparation for assembly joint JointRRP

Fourbar1

One kinematic loop with four bars (with only revolute joints; 5 non-linear equations)

Fourbar2

One kinematic loop with four bars (with UniversalSpherical joint; 1 non-linear equation)

PrismaticConstraint

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

Used in Components (4)

Cylinder

Cylinder with rod and crank of a combustion engine

Cylindrical

Cylindrical joint (2 degrees-of-freedom, 4 potential states)

Planar

Planar joint (3 degrees-of-freedom, 6 potential states)

RollingWheelSet

Joint (no mass, no inertia) that describes an ideal rolling wheel set (two ideal rolling wheels connected together by an axis)