All files stored in Teamcenter are referenced by a database object of type ImanFile. ImanFiles are stored as named references of Datasets
It would be good to know what you are trying to do with Mendix and Teamcenter/NX in order to be able to provide better advice. It is unusual to be dealing with ImanFile objects directly, as most interactions happen at the Dataset level instead, and are handled well by the Teamcenter Connector