Offset 40% FEA Comparison

This analysis is made to analyze the passenger safety of our concept lightweight car. Preliminary test in analysis shows that the head injury criteria improved (the value of HIC reduced by 5%) from the default model. However, the chest severity index increase about 3%. 

The video shows the default model at the top and the improved lightweight model at the bottom.

The comparison of energy balance.

Comparison Between the Default Car Model with Weight-Improved Car

I thought I should try to analyze, what if we change the heavy material in our car with the low density material such as aluminium alloys. Would it affect our safety? Yes it would, even though aluminium alloys are lighter, but its strength is lower compared to steel. Furthermore, some process for sheet metal such as hemming and stamping will be a bit difficult. This is because aluminium can easily crack under those process. However, even though it is difficult, it doesn't means that it is impossible. Visit the Aluminium Association on the documentation to explain the details in the manufacturing process for aluminium.

Changing a car to lightweight materials has a lot of advantage. First, it lowers the car fuel consumption. Second, it lowers the car kinetic energy, thus it will make the car safer in a crash event. In this simulation, I attempt to swap 90% of the steel in the model to aluminium. The weight reduction is around 300 kg of kerb weight.

The figure shows the energy balance between the default model and the improved model.

The top car in this video shows the default model while the bottom car is the weight improved car.

The Analysis of Jounce Bumper

This analysis was conducted to find the critical area of failure subjected fluctuated load. The actual part, the CAD data and the FEA analysis is shown in the following figure. Axi-symmetric element is used to speed up the simulation time.

The Side Impact

The side impact as in EuroNCAP. In the next simulation, I planned to change all to lighweight materials, to see whether it can withstand such test.

Pole Impact

The pole impact, in accordance to EuroNCAP.

ABAQUS

Abaqus has lots of interesting subroutine that can be used. For example, UVARM subroutine cam be created to read the value of stress and convert it into cycle to failure. This make engineers easier to tailor the design before proceed to production. In this model, a quarter model of rubber engine mount is analyzed. The fatigue correlation is obtained from literature which correlates the fatigue life with the value of strains.

The ODB - 40% Crash Test

EuroNCAP offset 40% analysis.

Full Car Crash

My first full car simulation which was modeled after a local Malaysian car. In the simulation, none of the material used has been validated. The simulation is just to test whether the full car model is similar to actual car model. However, in this preliminary test, the impact was made in accordance to US NCAP, which is full front impact to rigid wall at 56 km/h.

Tin Aluminium Can Impact

One of my most popular simulations. People always ask me on how I simulate the buckling in the impact. It is simple, include the stress-strain curve above the yield point, the shear failure and the damage evolution in the materials definition. An alternative to stress-strain curve, use the Johnson-Cook equation.