Relationship of the roof strength resistance with the displacement of top-end of A-pillar in CRIS test

Abstract

This paper examines whether the displacement of A-pillar top-end of vehicle in CRIS (Controlled Rollover Impact System) is related to roof strength. Current roof strength tests are not relevant to current rollover accident trends because the test condition is quasi-static. The ADAMS model of the vehicle was developed in this paper to compare the results obtained in the different test condition. This model consists of deformable upper-body members (A/B/C- pillars, Roof-bows, Side roof-rails) and a rigid under-body. The collapse behavior is considered by computing the characteristics of deformable members. This model was used to simulate quasi-static roof crush test and CRIS rollover test. The roof crush test condition (quasi-static) was adopted in accordance with the IIHS test protocol. The CRIS rollover test condition is selected to represent the trip-over type rollover given that a dynamic test protocol has yet to be developed. L27 orthogonal array is adopted for the DOE (Design of Experiment) analysis. The results show that the dominant member affecting roof crush resistance differs from the dominant member in dynamic test. Hence, the dynamic test should be used to evaluate the roof strength of vehicles. Nonetheless, roof crush resistance remains the minimum requirement for ensuring driver and passenger safety in the event of a roll-over accident.