A Novel Vehicle Glove Box Design for Mitigating Lower Leg Dummy Responses in a Vehicle Frontal Impact

Crash safety is a complex engineering field wherein a good understanding of energy attenuation capabilities due to an impact of various components and between different/adjacent components in the context of the vehicle environment is imperative. During a frontal impact of the vehicle, an occupant’s lower extremity tends to move forward and could impact one or more components of the instrument panel assembly. A glove box component design may have an influence on occupant’s lower extremity injuries when exposed to the occupant’s knees during a frontal impact. The objective of the present numerical study was to develop a novel glove box design with energy absorbing ribs and then comparing the results with the glove box with a knee airbag (KAB) design to help reduce anthropomorphic test device (ATD) lower leg responses. The finite element (FE) approach used in this study utilized morphing techniques with minimal design changes to the baseline glove box to simulate a sled test including an ATD and a restraint system. The width, height, and shape of the ribs design were optimized to mitigate the responses for the 5th and 50th percentile ATDs. For that purpose, multiple rib design shapes were developed for different crash dummies simulating different occupant sizes, crash pulses, and restraint conditions. The three cases investigated in the present study revealed that on an average there was 15% reduction in ATD lower leg injury responses with the addition of energy absorbing ribs to the glove box. Further, comparison of lower leg injury showed similar performance between the glove box with ribs and glove box with KAB. The study provided an effective solution in terms of cost, weight, and packaging to the overall product development cycle. In addition, rib design showed an adaptive solution with independent tuning for different size ATDs.