A TWO-LEVEL PRODUCT MODEL FOR SIMULATION-BASED DESIGN OF MECHANICAL SYSTEMS

摘要

This paper presents a two-level product modeling methodthat supports Simulation-Based Design (SBD) of mechanicalsystems, primarily ground vehicles and heavy equipment, forpreliminary and detailed design. A Computer-Aided Design(CAD) model combined with engineering parameters andmathematical equations that describe physical behavior of themechanical system constitute its product model for SBD. Forpreliminary design, improvement of system performance,including dynamics and human factors, is the primary focus. ACAD model with reasonably accurate physical parameters, suchas mass properties, is defined as the base definition of theproduct model. A parametric study can be conducted to searchfor design alternatives using dimension parameters created in theparameterized CAD model. Component designs are the primaryfocus in the detailed design stage. A detailed product model isevolved from that of the preliminary design, by refininggeometric representation of mechanical components in CAD andexpanding product assembly into parts and sub-assemblies forfurther engineering analysis. In the detailed design stage, asystematic design trade-off method is usually needed for designimprovement. In both design stages, CAD and Computer-AidedEngineering (CAE) mappings that tie dimension parameters inthe CAD model and physical parameters of simulation modelsfacilitate the parametric study and design trade-off by quicklygenerating simulation models to simulate performance of themodified design. A High Mobility Multi-Purpose WheeledVehicle (HMMWV) is employed to illustrate and demonstratethe modeling method.Keywords: Simulation-Based Design, Concurrent Design,Computer-Aided Engineering, Computer-Aided Design,parametric study, design trade-off.