Document ID: chunk:federal_register_of_legislation:F2012C00535:front:0:p35
Version: federal_register_of_legislation:F2012C00535
Segment Type: other
Provision Reference: 
Character Range: 95847–98834

which has been utilised,  and clear precise identification of the analysis software, including at least, its producer, its commercial name, the version used and contact details of the developer.

       1.2. The material models and the input data utilized.

       1.3. The values for defined masses, centre of gravity and the moments of inertia used in the mathematical model.

       2. The mathematical model

       The model shall be capable of describing the real physical behaviour of the rollover process, in accordance with Annex 5.  The mathematical model shall be constructed, and assumptions prescribed, in such a way that the calculation gives conservative results.  The model shall be built up with the following considerations:
       2.1. the technical service may require tests to be carried out on the actual vehicle structure to prove the validity of the mathematical model and to verify the assumptions made in the model.

       2.2. the total mass and the centre of gravity position used in the mathematical model shall be identical to those of the vehicle to be approved.

       2.3. the mass distribution in the mathematical model shall correspond to the vehicle to be approved.  Moments of inertia used in the mathematical model shall be calculated on the basis of this mass distribution.

       3. Requirements for the algorithm and simulation program, and for computing equipment

       3.1. The position of the vehicle in unstable equilibrium at point of rollover, and the position at first contact with the ground shall be specified.  The simulation program may start at the

       unstable equilibrium position, but shall start, at the latest, at the point of first contact with the ground.

       3.2. The initial conditions at the point of first contact with the ground shall be defined using the change of potential energy from the unstable equilibrium position.

       3.3. The simulation program shall run, at least, until the maximum deformation is reached.

       3.4. The simulation program shall produce a stable solution, in which the result is independent of the incremental time step.

       3.5. The simulation program shall be able to calculate the energy components for the energy balance at every incremental time step.

       3.6. Non-physical energy components introduced by the process of mathematical modelling (for example, "hourglass" and internal damping) shall not exceed 5 per cent of the total energy at any time.

       3.7. The friction coefficient used at the ground contact shall be validated with physical test results, or the calculation shall prove that the friction coefficient chosen produces conservative results.

       3.8. All the possible physical contacts between parts of the vehicle shall be taken into account in the mathematical model.

       4. Evaluation of the simulation

       4.1. When the stated requirements for the simulation program are met, the simulation of the changes in geometry of