Languages for User-Defined Member Design Processes

The power of a man-machine system for structural design is greatly enhanced if the engineer can conveniently define his own design processes to the computer. A general class of user-defined design procedures included within a timesharing version of the Structural Design Language (STRUDL) are examined. Problem-oriented languages are described for the specific tasks of interpreting a design code, selecting a suitably-proportioned section from a handbook of standard shapes, and checking selected members against the design code. Also, some internal system requirements included in STRUDL, which allow it to perform the processes the user has defined in an external language, are evaluated. Some of these characteristics allow the computer to interpret external languages and to generate the corresponding design programs for subsequent use by the engineer. Other system characteristics give these design programs access to the necessary design data. With these capabilities, the engineer can refer by symbolic names to any design data in the system and obtain their values for use in whatever design procedure he chooses. An example illustrates how user-defined processes for code checking and member selection may be flexibly combined with other Structural Design Language commands to form a sequence for the design of structural members.