CAD data visualization for machining simulation using the STEP standard

Abstract

There is a need for the integration of computer-aided design (CAD) information with manufacturing models, such as machining process simulation models, upstream with concurrent engineering activities. Because it is often difficult to interface various CAD formats with such applications, there is a need to standardize input file formats, which then can be used by any module that has the appropriate interface. The STEP standard is a very useful standard for the neutral file format specification. The present work describes in detail the building of a STEP parser for the Application Protocol for Configuration Controlled Design of 3-D mechanical parts (AP203). Such a STEP parser is complemented with a visualization front end in the form of a Java applet, which is used to display the STEP entities in 3-D within a web browser over the Internet. The current work outlines a generic framework for a STEP parser module. Its use in the design and development of CAD-based process engineering applications is illustrated by example of a CAD interface to a machining process simulation program, which requires the workpiece CAD information, namely the surface geometry, to be machined to determine chip loads and hence cutting forces. The applicability of the STEP parser in the building of a CAD database cataloging system is also discussed.