Representing the Charters of Freedom Encasements in a Design Repository: A Case Study

We report on a case study representing, in an evolving design repository, the design essence of new encasements for the United States Charters of Freedom (CoF) - namely the Constitution, the Declaration of Independence and the Bill of Rights. Specifically redesigned for the purpose of housing and preserving our national documents, the nine encasements each consist of three principal systems - a sealing system, a placement system and a safeguarding system. The encasements were needed to replace the ones manufactured in the early 1950s, because of glass deterioration; these newer encasements are designed to last 100 years. To populate the design repository, we represent engineering geometry, function and associated behavior. We model geometry with digital photographs and Virtual Reality Markup Language (VRML) models of actual Computer-Aided Design (CAD) drawings, and represent function with linked textual descriptions. Design rationale is represented explicitly. Through an evolving user interface, this representation serves to capture the more than 50 parts and systems of the encasements in such a way that the information relating to form, function, behavior and rationale is accessible and browsable to interested parties via the Internet. We conclude that such a representation, or ones similar to it, can provide the basis for a generic design repository, in which specific information - including design rationale - can be readily accessed by interested parties.