Declare a Spring Component

The following diagram shows a network representation of a mass-spring-damper system, consisting of four components (mass, spring, damper, and reference) in a mechanical rotational domain.

The domain is declared in a file named rotational.ssc (see Declare a Mechanical Rotational Domain). The following file, named spring.ssc, declares a component called spring. The component contains:

• Two rotational nodes, r and c (for rod and case, respectively)

• Parameter k, with a default value of 10 N*m/rad, specifying the spring rate

• Through and Across variables, torque t and angular velocity w, later to be related to the Through and Across variables of the rotational domain

• Internal variable theta, with a default value of 0 rad, specifying relative angle, that is, deformation of the spring

component spring 
  nodes
    r = foundation.mechanical.rotational.rotational; 
    c = foundation.mechanical.rotational.rotational;
  end 
  parameters
    k = { 10, 'N*m/rad' };   % spring rate
  end 
  variables
    theta = { 0, 'rad' };    % introduce new variable for spring deformation
    t = { 0, 'N*m' };        % torque through
    w = { 0, 'rad/s' };      % velocity across
  end
  % branches here
  % equations here
end

Note

This example shows only the declaration section of the spring component. For a complete file listing of a spring component, see Mechanical Component — Spring.