Engee documentation

Variable Translational Damper

Translational viscous damper with variable damping coefficient.

blockType: Engee1DMechanical.Elements.Translational.VariableDamper

variable translational damper

Path in the library:

/Physical Modeling/1D Mechanical/Couplings & Drives/Springs & Dampers/Variable Translational Damper

Description

Block Variable Translational Damper It is a translational viscous damper with a variable damping coefficient. The value of the variable damping coefficient is sent to the input port B. The magnitude of the damping force is equal to the product of the value at port B and the relative linear velocity between two non-directional ports. The minimum value of the damping coefficient prevents the occurrence of non-physical negative values of the damping coefficients.

The translational damping force satisfies the following expression:

where

  • — the force transmitted through a translational damper between two non-directional translational motion ports;

  • — coefficient of viscous damping;

  • — the minimum allowable damping coefficient;

  • — the relative translational velocity measured between two non-directional ports;

  • — port translational speed R;

  • — the forward speed of the port C.

The unit applies equal opposite damping forces to two non-directional ports. The sign of the damping force acting on the port R is equal to the sign of the relative velocity of translational motion. The positive velocity corresponds to a positive damping force acting on port R and a negative damping force of the same magnitude acting on port C.

Assumptions and limitations

  • The block represents only viscous damping.

  • The value of the damping coefficient must be greater than or equal to zero.

Ports

Conserving

# R — non-directional progressive port
translational mechanics

Details

Non-directional progressive port.

Program usage name

rod_flange

# C — non-directional progressive port
translational mechanics

Details

Non-directional progressive port.

Program usage name

case_flange

Input

# B — variable damping factor
scalar

Details

Variable damping factor.

Data types

Float64.
Complex numbers support

No

Parameters

Parameters

# Minimum damping coefficient — minimum damping factor
kg/s | N*s/m | N/(m/s) | lbf/(ft/s) | lbf/(in/s)

Details

The minimum permissible damping factor. If the value on port B is less than this value, it is equated to it. The value of this parameter must be greater than or equal to zero.

Units

kg/s | N*s/m | N/(m/s) | lbf/(ft/s) | lbf/(in/s)
Default value

0.0 N*s/m
Program usage name

C_min
Evaluatable

Yes