Week-7 Head Impact

Aim: To perform the head impact simulation using Ls-Dyna and calculate the hic(Head Impact criteria/coefficient) value.

Procedure:

Case 1: Impact of simple head form with rigid wall:

1. Creating section shell card:

2. Assigning material card:

3. Assigning section and material to the part.

4. Creating rigid wall.

To create the rigid wall, go to create entity >> rigid wall >> planar >> 3N >> select the 3 three nodes >> done.

5. Assigning velocity.

To assigining velocity, go to create entity >> initial >> velocity >> select the part >> enter the velocity value >> done.

6. Create control termination card.

7. Creating output request cards.

In addition to these, glstat , elout, nodout are requested in ASCII option.

Now run the simulation.

Case 2: Impact of child head foam against the rigid wall.

1. A new empty keyword file is opened and Include transformation and define transformation cards are created. Now the model is saved and opened again.

On opening the model again the model is rotated 45 along y-axis.

2. Create a rigid wall.

To create the rigid wall, go to create entity >> rigid wall >> planar >> 3N >> select the 3 three nodes >> done.

3. Assigning velocity.

The velocity is assigned to the head foam model in x and z direction.

4. Creating control termination card.

5. Creating output request cards.

In addition to these, glstat , elout, nodout are requested in ASCII option.

Now run the simulation.

Case 3: Child head foam against car hood.

1. Importing the hood model.

• After importing the hood model, define transformation and include transformation cards are created and model is saved.
• On reopening the model, the model head foam included in the hood file and is rotated about y axis in 45 degrees.

2. Creating section and material for the hood.

3. Assigning section and material to the part.

4. Assigning velocity.

The velocity is assigned to the head foam model in x and z direction.

5. Creating control termination card.

6. Creating output request cards.

• In addition to these, glstat , elout, nodout are requested in ASCII option.

Results:

The contour plots of von mises stress for all the models are shown below.

Energy Plots for all models.

HIC Results:

Conclusion:

Head impact simulation is performed using different cases and von mises stresses and HIC values are compared.

https://drive.google.com/file/d/1XSsyLo5L6BVoQM0qwLK8dkfJQNPXXImb/view?usp=sharing