spring

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spring

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Iconic Diagrams\Mechanical\Translation\Components

Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Translation).

Description

This model represents an ideal translational spring. The element has a preferred force out causality. The corresponding constitutive equations then contain an integration. The element can also have the non-preferred velocity out causality. The constitutive equations then contain a derivation. The spring model has separate high and low ports. The equations are

 

p.F = p_high.F = p_low.F

p.v = p_high.v - p_low.v

 

Force out causality (preferred):

 

x = int(p.v);

p.F = k * x;

 

Velocity out causality:

 

p.v = ddt(x);

x = p.F/k;

 

A positive force will compress the spring. The length x is positive when the spring is compressed. It is negative when the spring is stretched.

 

Interface

Ports

Description

p_high

p_low

Two ports of the spring (Translation).

Causality

 

preferred force out

An velocity out causality results in a derivative constitutive equation.

Variables

 

x

compression of the spring [m]

Parameters

 

k

Stiffness [N/m]

Initial Values

 

x_initial

The initial extension of the spring [m].