Object-Oriented Environment for Dynamic Finite Element Modeling of Tires and Suspension Systems

An object-oriented graphical modeling environment, which includes integrated pre-processor, post-processor, and explicit time-integration finite element solver, for predicting the dynamic response of tires mounted on suspension systems is described. The pre-processor allows creating a hierarchical preliminary model of the system including the tire, suspension system, and terrain. The pre-processor includes an automatic mesh generator for generating the finite element (FE) model from the preliminary model. A tire preliminary object allows defining the tire cross-section, specifying the number of elements along the tire circumference, and defining beam elements along the circumference and meridian direction to model the various tire structural components such as the bead, ply, and belt. Other preliminary model objects include rigid body, linear spring-damper, leaf-spring, spherical joint, revolute joint, prismatic joint, and polygonal terrain. The user can also include support objects such as physical materials, and scalar graphs (for time-histories of known quantities). The preprocessor includes a model tree-editor which allows adding objects and changing their properties. The FE model is submitted to the solver which generates the system's motion time-history. The FE model consists of solid elements (including brick, beam, and truss), rigid bodies, and joints. The post-processor is used to display the analysis results, which include an animation of the motion of the system, coloring/contouring the tire using various scalar response quantities, and various types of graphs of response quantities (such as time-history, frequency and time-averaged graphs). The graphical output of the pre-processor and the post-processor can be displayed either on the computer screen or in immersive stereoscopic virtual-reality facilities. Users can control the visualization using the tree-editor.