SysML is an emerging standard for the modeling of systems, providing a graphical way to model structure and behavior. Despite its flexibility, SysML lacks semantics to give language elements a precise meaning. Current implementations of the standard allow multiple interpretations of syntactical elements and can cause misunderstandings when porting a model among tools. Our work focuses on the definition of concrete semantics for SysML to enable correct interpretation of heterogeneous models. We also add semantic adaptation elements to guarantee that interactions among different formalisms are unambiguous. We demonstrate our approach by generating SystemC-AMS code automatically from SysML diagrams for a case study with two distinct formalisms. This kind of translation allows the validation of system behavior through simulation.