CAD conversion takes to the air

CAD conversion software converts design data for F-35 joint strike fighter programme

World-leading aerospace equipment supplier Smiths Aerospace has selected Theorem Solutions’ CADverter software to bridge different CAD systems during the development of integrated electrical power and remote input/output systems for the Lockheed Martin Joint Strike Fighter (JSF) programme. Smiths Aerospace is a first tier subcontractor, working in partnership with US company Hamilton Sundstrand. Both companies work within the JSF integrated product team, which is managed by Lockheed Martin. Smiths Aerospace is contracted to undertake the design and development of two key systems for the JSF programme: Electrical Power Management System (EPMS) Power Distribution and Management Systems reduce pilot workloads by providing fully automatic monitoring, control, protection and switching of aircraft electrical loads under normal and emergency conditions with load management, including automatic load shedding and restoration, to make best use of available power. "The JSF programme has been wholly dependent on computer generated design since the outset," says Smiths Aerospace Mechanical Design Team Leader, Graham Baldwin. "Last year we decided to replace drawings by storing all our Unigraphics and Pro/Engineer models in STEP format for distribution and direct translation into manufactured parts. Following this the American Joint Aeronautical Commanders Group have mandated standardisation on STEP as part of a Strategy for Product Data throughout the Life Cycle. "Because Lockheed Martin operates a CATIA system, which is incompatible with the Smiths Aerospace system, we chose Theorem’s CATIA/STEP AP203 bi-directional CADverter translator to send data in CATIA format for loading straight away onto Lockheed Martin’s system." Theorem's STEP CADverters convert data from CATIA, Unigraphics and other CAD systems into the standard STEP AP203 format. As well as geometric and topological data, assembly and attribute data is taken into the STEP AP203 format. A typical defence product will have a long service life and will undergo several major upgrades. Governments around the world increasingly specify STEP as the format for storing information on defence products. It is expected that the STEP standard will remain current longer than the proprietary formats of CAD vendors. Theorem was recommended to Smiths Aerospace by Lockheed Martin and has proved to be the vital link between the two companies. "We have also purchased a CADviewer from Theorem which enables us to view and interrogate our CAD designs and STEP models at a detailed level," concludes Baldwin. The first units developed by Smiths Aerospace for the JSF programme will be tested, along with other systems, on Lockheed Martin’s test rigs at the beginning of the second quarter of 2003. Full-rate production of between 3,000 and 6,000 aircraft, consisting of conventional-runway jet fighters, aircraft carrier and short take-off/vertical landing versions will begin in 2008 continuing until 2026. Delivery of the systems will commence in 2003 during the system development and demonstration phase. Low Rate Initial Production (LRIP) will commence in 2006 with the first of six lots, consisting of 13 aircraft. The JSF market consists of 3,002 aircraft for the U.S. Air Force, U.S. Navy, U.S. Marine Corps, Royal Navy and Royal Air Force. Another 2,000 are expected to be sold for export. MF