Side Pole impact Simulation following FMVSS 2214 guidelines

Aim:

To test the given BIW for side pole impact and request the appropriate results for the simulation test

steps:

1. Check the unit system used and follow the consistent unit system to define the bc’s and loading cases
2. To create appropriate interface with 0.2 friction value and other recommended parameters.
3. Check the model for initial penetration and interactions in the model and solve if any present
4. Create the rigid pole whose line of impact is in line of CG of the dummy head
5. Check for the CG of the vehicle, and add the appropriate masses where required
6. Apply the initial velocity of 8.888 mm/ms (32 km/hr) to the BIW model
7. Creat sections and request the section results in /TH file.

setup procedure.

Check for the unit system followed form the model from 0000.rad file.

the unit system of kg, mm, ms is followed for the rest of the cases in this simulation test.

Interface creation.

For the simulation interface Type 7 is created and all the surfaces are selected for master surface and all the nodes are selected for slave nodes (self impacting) type of interface.

Initial penetration and intraction check of the applied interfaces.

from the below image it is seen that their are no initial penetration or interaction present in the model.

Connectivity check

Check the given BIW model for possible free components which are not connected to any other parts and connect the free parts appropriately with rigid elements.

Three free parts are found in the model,

Rigid pole creation.

For side pole impact test analysis FMVSS 214 procedure is followed for this test, FMVSS 214 requires the vehicle longitudinal centreline of the vehicle to be at 75° to the 254mm dia impact pole reference line, and the impact reference line is inline with the CG of dummy head as shown in the figure below, taken from (Jones, 2012)

similar case is setup for the analysis with search distance of 1500mm.

Mass addition and Centre of gravity check.

Initial velocity.

initial velocity of 8.88 mm/ms is applied to the model in accordance with the FMVSS 214 procedure.

Time step control 

The minimum time given to the model is 2e-4 ms (0.2 microseconds).

this information can be seen from the 0001.rad file generated by the radioss.

Section Creation.

To know the resultant forces in the cross members cross sections are created in the cross members and requested in /TH

Model checker

 Befor we run the simulation, we reun the model checker for possible error ditection, if any their are any errors in the model it is important to clear them before the simulation run.

there are no errors found in the model, the warnings for this model do not effect the results or the simulation run, hence the model is ready for analysis.

Results:

 Time taken for simulation and number of cycles.

The simulation took 1hr 31min 96sec for completion and normal termination message is shown which indicates the simulation was successful

Energy and mass error.

From the above 0001.out file the simulation time step is at 0.315e-3 ms which is bigger than the applied time step value of 0.2e-3 ms, hence there is no mass addition in the system which can also be observed in the image i.e., Mass error in the system is 0%.

Energy error at the end of simulation is at -1.3% which is under the recommended value, hence the simulation results are under the acceptable range.

Energy graph.

Forces in Cross-members

Seat-REI part has a extra reinforcement part to reduce the deformation at the driver location, which can seen in the image above, due to which the forces in the SEAT-REI parts has lower value than the RAILS-U-MID part as observed from the below graph.

Velocity at the Driver door location.

Peak velocity observed in the graph is at 10.92 mm/ms which occurs at 20th ms of the simulation, it is the time at which the vehicle impacts the side pole, agter it reachs the peak the velocity decreases with time, as seen in the above graph.

Displacement values at selected parts

The above graph shows the displacement value at 3 different location, B-Pillar location, hing location and fuel tank location.

As the vehicle impacts the side pole the displacement value in all three locations increase with the time, final displacement at Hing and B-Pillar are almost similar at the range of 320mm where as displacement at fuel tank location 380 mm which is much higher compared to other parts.

To reduce the deformation at fuel tank area a cross member similar to that at drivers cross member as can be introduced, which will add stiffness to the structure and helps reduce the deformation.

Conclusion.

Side Pole impact analysis is carried out in this project following the FMVSS 214 setup procedure, and various results are presented such as deformation at different locations, sectional forces in the cross members and velocity graph of a node placed on the driver side seat are discussed.

References.

Jones, J. (2012) ‘NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION LABORATORY TEST PROCEDURE FOR FMVSS No . 214 , DYNAMIC SIDE IMPACT PROTECTION -Moving Deformable Barrier Impact Test Requirements- APPENDIX A Office of Vehicle Safety Compliance’, (September), pp. 1–20.