To get started with integrating Rational Rhapsody with the MathWorks Simulink software, see Integrating Rational Rhapsody and the MathWorks Simulink.
To learn how to import a MathWorks Simulink model into Rational Rhapsody and then simulate the two models together, see the demonstration in the IBM developerWorks topic at http://www.ibm.com/developerworks/offers/lp/demos/summary/r-rhapsodysim.html.