Evaluation of Corpuscular Particle Method (CPM) in LS-DYNA for airbag modeling 2020-01-0978
This paper presents a systematic study performed to assess the maturity of Corpuscular Particle Method (CPM) to accurately predict airbag deployment kinematics and its overall responses. The critical phases of the study involved, firstly, an assessment of correlation of CPM predicted inflator characteristics to closed tank tests. Secondly, a correlation assessment of CPM for deployment characteristics, airbag pressure and reaction force for a static deployment test of a Driver Airbag (DAB). Lastly, the impactor force predicted by CPM was correlated against physical drop tower tests. All these studies were repeated using traditionally used Uniform Pressure Method (UPM), to compare the numerical methods for their accuracy in predicting the physical test, computational cost, and applicability.
The results from these studies suggest that CPM satisfies the fundamental energy laws, and accurately captures the realistic airbag deployment kinematics, especially during the early deployment, unlike UPM. For a fully deployed DAB, the airbag pressure, reaction force, and the impactor force are accurately predicted by both CPM and UPM. Additionally, the computational cost of CPM was observed to be on par with UPM, in spite of the discretized fluid model and the need for a more detailed airbag FEA model. However, in the early deployment phase, CPM did not accurately predict the reaction force due to airbag deployment and the airbag pressure measured in the physical tests. This suggests a limitation in the application of CPM, making it a suitable modeling method for occupant protection due to interaction with a fully deployed airbag, while limiting its scope for early deployment applications such as Out-of-Position (OOP), roof-rail and tear seam failure due a deploying airbag etc.
Neeharika Anantharaju, Kalu Uduma, Yibing Shi