# Translational Damper

Linear translational damper

Libraries:
Simscape / Driveline / Couplings & Drives / Springs & Dampers

## Description

The Translational Damper block models a linear translational viscous damper. From the start of the simulation, the block uses the nominal damping coefficient. If you enable faults for the block, the damping coefficient changes in response to one or both of these triggers:

• Simulation time — A fault occurs at a specified time.

• Simulation behavior — If the magnitude of the translational acceleration exceeds a specified maximum value, the block increments the number of shocks by one. A fault occurs if the number of shocks exceeds a specified maximum number of shocks.

If a fault trigger event occurs, the block uses the faulted damping coefficient for the remainder of the simulation. You can program the block to issue a fault report as a warning or error message.

The defining equations are

$F=Dv$

and

$v={v}_{R}-{v}_{C},$

where

• F is the force transmitted through the damper.

• D is the damping (viscous friction) coefficient.

• v is the relative velocity.

• vR and vC are the absolute velocities of terminals R and C, respectively.

The positive block direction is from port R to port C. Therefore, the torque is positive if it acts in the direction from R to C.

### Thermal Modelling

You can model the effects of heat flow and temperature change by enabling the optional thermal port. To enable the port, set Thermal port to Model.

Enabling thermal modelling exposes the Thermal mass parameter.

## Ports

### Conserving

expand all

Mechanical translational conserving port associated with the rod interface.

Mechanical translational conserving port associated with the case interface.

Thermal conserving port associated with heat flow. Heat flow affects damper temperature, and therefore, power transmission efficiency.

#### Dependencies

To enable this port, set Thermal port to Model.

## Parameters

expand all

Main

The oscillation-reducing force due to viscous friction that the block applies if no trigger events occur. Specify a value that is greater than or equal to zero.

Faults

To enable the block to use a different damping coefficient based on the simulation time or when the magnitude of the translational acceleration exceeds the specified number of shocks, select On.

#### Dependencies

Selecting On makes these parameters visible:

• Faulted damping coefficient

• Enable temporal fault trigger

• Enable behavioral fault trigger

• Reporting when fault occurs

The oscillation-reducing force due to viscous friction that the block applies if a trigger event occurs. Specify a value that is greater than or equal to zero.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter.

To use the faulted damping coefficient starting at a specified time in the simulation, select On.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter.

Selecting On makes the Simulation time for fault event parameter visible.

Specify the time during the simulation that you want the block to start using the faulted damping coefficient.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter and On for the Enable temporal fault trigger parameter.

To use the faulted damping coefficient when the number of sustained shocks exceeds a specified maximum number of shocks, select On.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter.

Selecting On makes these parameters visible:

• Maximum permissible acceleration

• Maximum number of shocks

The maximum value that the magnitude of the translational acceleration can reach without causing the block to increment the number of sustained shocks.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter and On for the Enable behavioral fault trigger parameter.

The maximum number of shocks that can be sustained without triggering the block to use the faulted damping coefficient.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter and On for the Enable behavioral fault trigger parameter.

Select your reporting preference for the fault condition.

#### Dependencies

This parameter is only visible if you select On for the Enable faults parameter.

Thermal port

Option to model effects of heat flow and temperature change.

Thermal energy required to change the component temperature by a unit increase. The thermal mass represents the ability of the damper to absorb and retain heat energy.

## Version History

Introduced in R2016b