Influence of the different vehicle subframe configurations in the PDB assessment
Examensarbete för masterexamen
Riazi, Amir Reza
There is no consideration for crash compatibility of passenger vehicles in safety regulations. The EU Project FIMCAR is investigating different frontal crash tests that can assess a vehicle’s frontal crash performance for both self and partner protection. Existing candidates need further development in establishing an objective measurement from the test data. The PDB (Progressive Deformable Barrier) is one of the candidates with ability to detect load distribution of a vehicle frontal structure in a crash. Deformation of the PDB barrier surface is used to evaluate vehicle performance. The proposed PDB barrier and evaluation process needs further investigation before acceptance for vehicle regulatory or consumer testing. The PDB’s ability to detect different front end structural configurations of a vehicle was evaluated by simulations. A finite element model of the vehicle (2001 Ford Taurus) and the PDB were used. The vehicle performance benefits of different sub-frame configurations were indentified with car-to-car simulation results that were used as the reference for car-to-PDB simulations. A new protection criterion of a partner vehicle in crash was also developed using available PDB test results. The performance differences of various sub-frame configurations were detected through the car-to-car simulations. Initial car-to-PDB simulation results were not able to detect these differences because of issues with components of the PDB. For this reason, the PDB model was modified to improve lower structural interaction detection. The modified PDB showed better results. The results of the physical PDB and the FE PDB simulations were evaluated with the developed criteria. The new PDB criteria worked well with scanned physical PDB deformation faces, but not with the unmodified PDB simulation results. This discrepancy may be due to the removal of covering structures in the vehicle FE model that created a more aggressive car structure than a true production car. The PDB was able to detect different sub-frame configurations. The car-car results showed that the longer sub-frame configuration increases self protection because structural interaction starts earlier in the crash. Due to the limitations of the PDB and vehicle models used in the project, the proposed criteria did not properly assess the different subframe configurations. Further work is needed to confirm the criterion is robust to apply in frontal crash compatibility evaluation.
Transport , Farkostteknik , Transport , Vehicle Engineering