Steel Structure Joint's Virtual Assembly Based On Java3D

Steel structure joint's design is the important and difficult point of steel structure's design, and inflexible when adopting traditional CAD (Computer Aided Design) technique, so virtual assembly is introduced to steel structure joint's design, and virtual assembly environment which both supports mouse's interaction (including picking) and parametric interaction is created, and the assembly model is represented by XML (Extensible Markup Language), parametric modeling for section steel, steel plate, bolt and so on is based on facets, so high precision 3-dimension solid modeling, interactive 3-dimension operation and visualization 3-dmenstion view are integrated.In detail, steel structure joint's virtual assembly is divided into 2 phases: earlier phase of virtual assembly and later phase of virtual assembly. Respective technique is adopted in different phases: in the earlier phase of virtual assembly, the parts are interactively assembled one by one based on facets to form the assemblies which are in common use for the final products; in the later phase of virtual assembly, reuse and reconstruction technique is adopted and the finished assemblies in the earlier phase will be use again to implement assemblies'automatic assembly.Reuse is the foundation of automatic assembly's implementation, and includes 2 kinds of form: instant copy, import and export; reconstruction is the important point of automatic assembly's implementation, and its essential process is to automatically modify the primary position according to the referring steel structure joint and by the aid of the picking point and relating facets.Moreover, three views and automatic dimension is study for steel structure joint. In the automatic dimension, interference will not occur between the dimension symbol and dimension text, dimension entities, dimension entity and primitive in views.Java 3D? is 3-dimension graphics API (Application Programming Interface). According to the study, program is coded based on Java? language and Java3D. With the program, varied steel structure joints are assembled and can further be assembled to a steel structure framework, so experimental steel structure's design is implemented.