Toward a theory for design of kinematically constrained mechanical assemblies

This paper summarizes a theory to support the design of assemblies. It desc ribes a top-down process for designing kinematically constrained assemblies that deliver geometric key characteristics (KCs) that achieve top-level cu stomer requirements. The theory applies to assemblies that take the form of mechanisms (e.g., engines) or structures (e.g., aircraft fuselages). The p rocess begins by creating a kinematic constraint structure and a systematic scheme by which parts are located in space relative to each other; followe d by declaration of assembly features that join parts in such a way as to c reate the desired constraint relationships. This process creates a connecti ve data model containing information to support relevant analyses such as v ariation buildup, constraint analysis, and establishment of constraint-cons istent assembly sequences. Adjustable assemblies, assemblies built using fi xtures, and selective assemblies can also be described by this theory.