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FTire/sim generates and analyzes a coarse finite-element mesh on basis of certain tire design data. These data, in turn, can be parameterized using very few key values of the tire design, like for example
- tire and rim size in standard notation,
- few dimensionless x/y-data pairs describing tire cross-section (automatically scaled by tire size),
- belt and tread width relative to tire width,
- tire total mass,
- estimated relative mass shares of bead, side-walls, belt, and tread,
- belt chord angle,
- belt chord thread diameter,
- belt chord thread density,
- young’s modulus of carcass chord thread,
- carcass chord thread diameter,
- carcass chord thread density,
- young’s modulus of tread rubber,
- tread depth,
- estimated tread rubber friction coefficients,
etc.
FTire/calc uses the coarse FE model to automatically calculate some modal properties and to solve a series of non-linear static load-cases. The results of these ‘virtual measurements’ determine the structural stiffness and damping properties of FTire. FTire/calc uses them to automatically generate a ready-to-run FTire data file.
Some parameters of FTire, however, cannot be calculated in such an easy way, like the friction properties of tread rubber on road surface, for example. These parameters will just be copied from the FTire/calc input file to the FTire data file.
FTire/calc also provides some means to analyze the design data prior to generating an FTire data file. It can
- display eigen-frequencies and animated mode shapes of the internally generated FE model,
- calculate single static load-cases, and
- display distorted FE grids, stresses, and ground pressure distribution on flat surface and special obstacles.
After having completed the generation of the FTire data file, FTire/calc can be used
- to check the file for ‘FTire integrity’ (that is, whether or not FTire pre-processing runs successfully),
- to analyze and process the file by FTire/tools, or
- to launch stand-alone FTire simulations with FTire/sim.
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