modelQuadratureLobatto3

Integrate function in a model

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

Technically, this example demonstrates how to utilize a function as input argument to a function in a model.

From a modeling point of view, the example demonstrates in very simplified way the basic approach to model distributed systems with the Ritz method. The displacement field u(c,t) of a particle (where c is the undeformed position and t is time) is hereby approximated by space-dependent mode shapes Φ(c) and time-dependent modal amplitudes q(t), that is u = Φ(c)*q(t). When inserting this decomposition in the equations of motion and then integrating over all particles, terms such as ∫(Φ(c) dc)*q(t) appear, where the time-invariant integral term can be computed beforehand once with the Lobatto method. By this approach the partial differential equations are transformed to a system of ordinary differential equations.

Parameters

TypeNameDefaultDescription
RealA1Amplitude of integrand of s
Realws2Angular frequency of integrand of s
Realwq3Squared angular frequency of q
RealsModelica.Math.Nonlinear.quadratureLobatto(function UtilityFunctions.fun7(A = A, w = ws), 0, 1)Time-invariant integral value

Components

TypeNameDefaultDescription
RealqFirst-order state variable
RealqdSecond-order state variable
RealxOverall value as product of s and q