Brake - MapleSim Help
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Rotational Brake

Brake based on Coulomb friction

 

Description

Connections

Parameters

Modelica Standard Library

Description

The Rotational Brake (or Brake) component models a brake. A frictional torque acts between the housing and a flange and a controlled normal force presses the flange to the housing to increase friction.

Normal Force

The normal force applied to the braking surface is the product of a parameter, , and a normalized input signal, .

Friction Force

When the absolute angular velocity is not zero, the friction torque is a function of the velocity dependent friction coefficient  , the normal force, , and a geometric constant, , which takes into account the geometry of the device and the assumptions on the friction distributions.

The geometric constant is calculated as

where  is the inner radius,  is the outer radius, and  is the number of friction interfaces.

Friction Table

The positive part of the friction characteristic, , is defined by the  parameter as a two-dimensional table (array) that specifies the sliding friction coefficients at given relative angular velocities. Each row has the form . The first column must be ordered, . To add rows, right-click on the value and select Edit Matrix Dimension. Only linear interpolation is supported.

Connections

Name

Description

Modelica ID

Flange of left shaft

flange_a

Flange of right shaft

flange_b

Conditional Support Flange

support

Optional heat port

heatPort

Real input; normalized force

f_normalized

Parameters

General Parameters

Name

Default

Units

Description

Modelica ID

Table of sliding friction coefficients at given relative velocities

mue_pos

 is the static friction coefficient

peak

Geometry constant containing friction distribution assumption

cgeo

Maximum normal force

fn_max

Use Heat Port

 

True (checked) means the heat port is enabled

useHeatPort

use Support Flange

 

True (checked) means the support flange is enabled

useSupport

Advanced Parameters

Name

Default

Units

Description

Modelica ID

The velocity reinitializes when

w_small

Gain driving the relative motion between the friction elements to 0 when locked. This parameter should only be non-zero when using the model with fixed-step integration.

K_locked

Modelica Standard Library

The component described in this topic is from the Modelica Standard Library. To view the original documentation, which includes author and copyright information, click here.

See Also

1-D Mechanical Overview

Rotational Clutches and Brakes

 


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