CPM (Corpuscular Particle Method) is widely used as a standard simulation technique for airbag deployment simulation among users for a long time. It is very fast and robust for most of the cases. On the other hand, we may need additional effort to reproducing the realistic gas flow around narrow area such as curtain airbag, vents, and so on. A new fluid solver (CPG ; Continuum-based Particle Gas) has been developing to reproduce it by directly solving the Navier-Stokes equation. 3 types of simple airbag tests are suggested and conducted to validate the CPG solver. Due to inviscid and free slip assumption for now, the gas frontal speed is faster than tests, but CPG showed a good result in terms of gas flow around narrow area.
The authors have previously published a paper characterizing a laminated glass pane to simulate the delamination and fragmentation response of glass in a blast event. In this study, a computational model in LS-DYNA was developed and correlated with physical testing of laminated safety glass panes subjected to blast loads. To generate an accurate model, validation of the component parts including Polyvinyl Butyral (PVB), adhesion and glass that make up the laminated safety glass was completed.
The automotive industry is continually evolving to meet stringent safety standards and enhance occupant protection in crash scenarios. With Euro NCAP supplementing far-side impact testing with Virtual Testing Crashworthiness (VTC) starting in 2024, real tests and CAE simulations come closer more than ever. The VTC protocol mandates the use of simulation and physical test data to robustly evaluate far-side impact protection, requiring detailed compliance with validation and quality criteria, as well as specific data formatting for submission. Consequently apart from far-side more protocols will be implemented in the virtual testing raising more challenges to the safety engineers. As a result there is an increasing need for efficient tools that streamline the assessment process offering ‘know how’ of the different protocols and simultaneously minimize the human interaction with the aid of automation.
This work assesses the effectiveness of a proposed interconnected multi-bollard design in protecting bus stop occupants from incoming vehicles. A detailed model of a 3-bollard system was developed in ANSYS LS-Dyna®, which included the bollards, their underground support structures, and the rebars connecting the bollards. The bollard system was composed of 116 parts with a total of 443,799 elements. The system model was merged with a detailed model of a 2007 Chevrolet Silverado, 4-door crew cab pickup truck with 603 parts with 251,400 elements developed by the Center for Collision Safety and Analysis [1]. The vehicle was simulated to impact the bollard system at speeds between 15 and 90 mph at angles ranging from 0° (normal to the bollard system) and 90° (parallel to the bollard system). Impacts were also made at various degrees of centeredness, with cases showing response from impact at the center of bumper, as well as at the edge of the bumper. With each case, vehicle velocity and acceleration were monitored using virtual accelerometers, placed in the vehicle to assess the effectiveness of the bollard to stop the vehicle. Simulation results show that the bollard was able to stop a vehicle traveling normal to the bollard system, impacting the center of the bumper at speeds up to 45 mph. However, the vehicle would continue past the bollard system at higher speeds.
In 2024 the Euro NCAP Virtual Testing far-side protocol was introduced with a monitoring phase. The protocol defines all the requirements in precise detail. To obtain an assessment for the virtual testing, the OEM needs to pass two validation load cases. The assessment is conducted using ISO/TS 18571 ratings. Euro NCAP is responsible for the ISO/TS 18571 rating calculations. The OEM must provide the simulation and test data in a predefined ISO MME data format. If the ratings meet the defined criterion, the virtual testing assessment is deemed successful. This paper presents a straightforward workflow for preparing ISO MME data, illustrated by a case study of a far-side test involving the open-source Toyota Yaris car and the DYNAmore WorldSID 50th dummy model in LS-DYNA. The DYNAmore Eco System tool DM.binout2isomme is used to create the required ISO MME files for sharing with Euro NCAP. Furthermore, the ISO/TS 18571 scores are calculated with a Python script with the same procedure as defined by Euro NCAP.
Preliminary Validation of New Continuum-based Particle Gas (CPG) Method for Airbag Deployment Simulations