Mass

A sliding mass with two flanges: m·a = f_a + f_b.

  • translational
  • Modelica Standard Library
  • 2 ports
  • 1 parameter
BlockMassKindmassLibraryTranslational

Description

A sliding point mass with two flanges, both at the position of the mass. It has no friction; add a Damper to Fixed (translational) for viscous losses.

Example

Mass, spring, and damper Two 1 kg masses on 100 N/m springs and 2 N·s/m dampers, pushed by 1 N, with every translational sensor.

Force step 1 NApplied forceMass 1 kgSpring-damperWallPositionVelocityAccelerationForce 1 NMass 1 kg (lower)Spring 100 N/mDamper 2 N·s/mWall (lower)Spring compressionPosition (lower)
In Gradara, select a Mass block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:Fixed (translational)SpringDamperSpring-damperConstant forceForce stepPosition sensorVelocity sensorAcceleration sensor (linear)Force sensorRelative position sensor

Ports

Conserving terminals 2

  • aflange_atranslational

    Flange a. Force into the flange is positive.

  • bflange_btranslational

    Flange b, at the same position as flange_a.

Parameters

  • Massm1 kg

    ≥ 0

    Mass, in kilograms. Zero or positive.

Equations

Modelica
flange_a.s = flange_b.s = s
v = ds/dt
m · dv/dt = flange_a.f + flange_b.f

Implementation

Modelica Standard Library 4.1.0Modelica.Mechanics.Translational.Components.Mass
MSL documentation

Assumptions and limitations

  • No friction, no end stops, and no length (both flanges at one point). For stops and friction, use Mass with stops.

Used in

These larger examples use it too. Open them from Examples in the app.

  • EV drivetrain

See also

Select a block in Gradara and press F1 to open its page offline.