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2 STRUCTURES / LS-DYNA Models // / Tire Models: • Jointly developed with Fiat Chrysler Automobiles (FCA) and based on a series of material, verification and component-level tests. • Finite element mesh developed based on 2D CAD data included in the tire section • Different tire sizes were developed using geometrical resizing of the reference tire • Air loss modeled using a combination of sensors and porosity and venting • 240,000 hexahedron solid elements formulation • Inflation based on AIRBAG_HYBRID • Deflation based on sensor to triggering leakage • Plug and play with no additional contacts when using in vehicle • Elastomer modeling using MAT_SIMPLIFIED_ RUBBER with rate dependency • Ply modeling using MAT_ORTHOTROPIC_ELASTIC • Wheel mounting modeling using LOAD_THERMAL_ VARIABLE In the small-overlap load case, the tire plays a significant role during the early stages of impact. Tire compression and subsequent deflation (shown here) are represented in a full 3D stress state. The new solid tire model improves the predictive capability due to its accurate discretization, material properties and pressure-based interface with the wheel. The right image displays the tire section during the maximum compression. LS-DYNA's superior material properties and contact-impact using segment-based contact was key in simulating this event. A look at the sectional view of the tire in a component simulation used for validating the tire's pressure and stiffness. The dark and light grey components represent the homogenous elastomeric parts such as tread, sidewall, etc. The red and yellow parts represent the orthotropic plies. An example of the library of tire models currently available. Based on several experiments, tires of same size but from different manufacturers displayed similar stiffness. This was also reflected by tires of different sizes and from different manufacturers. This data was used to geometrically morph a single validated tire (above, with blue digits) to generate tires of other sizes.

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