The growing market share of electric lightweight vehicles requires new passive safety strategies as these vehicles have different behavior in accidents compared to conventional vehicles. Due to their low weight they could experience high deceleration pulses and intrusion levels. The main objective of this study was to develop a passive safety strategy for a light weight electric vehicle to give best in class occupant protection. Challenges involved in this study include, mainly focused on side impact:​

• The use of alternative materials for the body structure (mainly sandwich panels and foam) due to their failure mechanism
• A novel seating layout with a centrally positioned driver, especially challenging for side impact

Within this study two baseline and four final prototypes were built. The development of the vehicle was accompanied by FE-simulation. Two of the baseline prototypes were subjected to Euro NCAP MDB side and ODB frontal impact crash tests. These baseline crash tests served as benchmark for the development of the passive safety strategy and the validation of the FE-model. For side impact two critical issues have been taken into account, namely a high ∆v and a centered driver position which reproduces the current challenge for far‐side protection. Firstly, FE simulations have been done to develop the restraint systems, followed by sled test development loops in the main Euro NCAP load cases (MDB, Pole and ODB). With the final prototypes a full Euro NCAP crash assessment was performed using the ‘year 2013’ rating protocols to allow comparison with the baseline crash tests.

The MDB side impact led to very high pulses, that couldn’t be addressed structurally due to the high mass ratio between barrier and vehicle. However, the results show that with the proposed restraint system using airbags and a four point seatbelt an adequate protection level could be reached for the centered driver for both MDB and pole side impacts, compared to standard vehicles. For frontal impact, the results showed that, using an approach of a strong compartment built from novel composite reinforced glass fiber / foam panels, combined with a specially designed energy absorption module, an ‘innovative’ four-point seatbelt and a conventional driver airbag, resulting intrusion could be minimized and adequate protection could be offered to the driver. Overall occupant protection equivalent to a best in class Euro NCAP ‘year 2013’ rating was achieved for the vehicle.

The strategy developed demonstrated equivalent protection levels based on the Euro NCAP ‘year 2013’ suite of tests. Since then, the Euro NCAP assessment has been further improved in terms of representativeness of real-world accidents. These improvements include a heavier barrier for the MDB test and the addition of a full width frontal test.

With respect to growing market share of electric lightweight vehicles a passive safety strategy was developed for such vehicles based on Euro NCAP crash tests to give best in class occupant protect ion. Because of the centrally positioned driver, some challenges have been faced and solved, especially for side impact configurations.