This presentation was made at the 2019 NAFEMS World Congress in Quebec Canada
Thousands of pedestrians die due to road accidents in the world, especially in India, every year. Head injury, being more life threatening, is the most common cause of pedestrian deaths during pedestrian-to-vehicle front collision scenarios. To reduce head injury occurrences, different International Safety Committees have developed homologation tests wherein headform shaped impactors are impacted upon passenger vehicle and utility vehicle front hoods, while measuring the head acceleration within specified pass/fail range.
During initial stages of vehicle development, use of computer simulation is essential to make the design compliant to different safety standards, including pedestrian safety. Since this is without the availability of a vehicle prototype, it is essential to predict vehicle performance accurately using FE simulation.
Different privately owned FE Adult and Child Headform models are available in different solvers across the globe. Since these are available on cost basis, it adds to the existing magnanimous product development cost. This necessitated the development of open source FE models (initially in LSDYNA® solver format) for use of the general public.
3D Scanning of physical adult and child headform impactors were performed to prepare 3D CAD geometry. Through material characterization, material properties of each headform component were mapped and converted to LSDYNA® material cards. These developed headforms were validated initially for calibration tests as required by homologation standards AIS 100 / GTR 9. This was also useful to setup simulation methodology for next phase of simulations.
Post initial validation, these FE models were impacted on different passenger vehicles in computer simulation, while the physical impactors were impacted on similar category vehicles. The yielded simulation results for head acceleration correlated well with the physical test results, further validating the FE models created thus.
These validated FE models would be useful towards initial design evaluation and would play a major part in reducing vehicle development costs through prototype reduction.
|Date||18th June 2019|
|Organisation||Automotive Research Association of India (ARAI)|