A NEW GENERATION OF TOOLS FOR MECHANICAL SYSTEMS SIMULATION

MECHANICAL SYSTEMS SIMULATION (MSS) IS THE TECHNOLOGY ASSOCIATED WITH THE ANALYSIS OF SYSTEMS UNDERGOING LARGE OVERALL MOTION. AN AUTOMOBILE PERFORMING A LANE CHANGE MANEUVER AT 55 MPH AND A SPACE SHUTTLE ORBITING THE EARTH WHILE PERFORMING SATELLITE RETRIEVAL, ARE TYPICAL EXAMPLES. THE STABILITY AND EFFICIENCY OF THE NUMERICAL SOLUTIONS FOR THESE SYSTEMS AND THE RELIABILITY OF SYSTEMS ANALYZED ARE DEPENDENT ON THE CHOICE OF SYSTEM COORDINATES, EQUATION FORMULATION PROCEDURES, AND NUMERICAL METHODS. YET COMMERCIALLY AVAILABLE MSS CODES ONLY SUPPORT, EVEN ESPOUSE A SINGLE CHOICE. RESEARCHERS ARE DEVELOPING A SYMBOLIC COMPUTATION-BASED SOFTWARE THAT ALLOWS FOR USER-DEFINED CHOICES. THE NECESSARY FUNCTIONS AND DATA STRUCTURES FOR SYMBOLIC EXPRESSION MANIPULATION, SYSTEM DEFINITION, COORDINATES SELECTION, EQUATION FORMULATION, AND NUMERICAL METHODS ARE BEING CREATED IN STAGES. SYSTEM EQUATIONS ARE SYMBOLICALLY GENERATED AND STORED IN CANONICAL FORM FOR SUBSEQUENT TRANSLATION INTO FORMATS FOR VIEWING THE EQUATIONS OR COMPUTING THE SYSTEM RESPONSE. THE SOFTWARE ALLOWS THE USER TO ACCELERATE CODE DEVELOPMENT, EVALUATE ALTERNATIVE METHODS, AND TAILOR SIMULATION CODES TO INDIVIDUAL PROBLEMS. THE RESULTING COMPUTATION EFFICIENCY LEADS TO NEW APPLICATIONS SUCH AS REAL-TIME ANALYSIS, AND ALLOWS SOLUTION OF LARGER PROBLEMS ON LOWER PERFORMANCE HARDWARE.