One way to build safe critical systems is to formally model the requirements formulated by stakeholders and to ensure their consistency with respect to domain properties. This paper describes a metamodel for a domain modeling language built from OWL and PLIB. The language is part of the SysML/KAOS requirements engineering method which also includes a goal modeling language. The formal semantics of SysML/KAOS models is specified, verified, and validated using the Event-B method. Goal models provide machines and events of the Event-B specification while domain models provide its structural part (sets and constants with their properties and variables with their invariant). Our proposal is illustrated with a case study dealing with the specification of a localization component for an autonomous vehicle.