Assignment 7-Side Pole Crash Simulation Challenge

Objective:

To perform side pole crash analysis on given vehicle structure and report obervations based on the output received.

Unit system check:

The unit system used is Kg mm ms

Inteface creation.

The unnecessary interface is removed and a single interface (TYPE 7) is created with necessary parameters.

Rigid Wall

A rigid pole of dia 254mm is created with friction 0.1 on side of vehicle.

Mass correction and CG

The mass of the vehicle is increased to reach 700kg and Centre of gravity is ensured to be near driver.

Initial velocity

Initial velocity of 35 mph or 15.6mm/ms is applied to all the nodes.

Time step and Engine card

Time-step is kept for 5 microsecond.Simulation is run for 80 ms.Animation frame frequency is set to 5ms.

Output requests

Section

Section is created at two traverse crossmembers with recommended parameters to measure the force as shown below.

Penetration B pillar, Fuel tank and Hinge.

Springs are created at Bpillar, Fuel tank , driver compartment and Hinge with negligible stiffness and mass, so that the deformation of the spring is measured to identify the intrusion in respective zones.

Driver door velocity.

The time history of given node in driver inner panel is added with respect to the frame created on opposite structure of vehicle so that the maximum velocity of intrusion can be measured.

Check points

The model is checked for penetrations by selecting Tools --> penetration. No penetrations are found

Then also model is checked for errors and warnings by selecting

Quality--> Model checker --> Run in Hypercrash.

There where no errors and warnings where acceptable.

Output graph and Observation.

The model is run by Analysis--> Radioss. Then the output generated is analysed.

Output check

The output file have energy error less than 15%. So, the output is acceptable.

Sections at cross member

The output graph for force received on each part against time is plotted below.

Observation:

From the graph above it can be seen that the peak force of 4kg is received at crossmember 1. In case of crossmember 2 force is well distributed through the time and peak force is less (3kg). This is beacause the X coordinate Pole position and COG is same as crossmember 2.

Penetration at B pillar, Fuel tank, Driver compartment and Hinge pillar

The deformation of the spring created earlier is plotted against the time so as to measure the intrusion of the respective zones.

Observation:

The intrusion in respective zone is as shown above.We can observe that maximum intrusion of 900mm is shown at driver compartment of the vehicle. This can negatively impact the crash performance of the vehicle. To reduce the intrusion more number of cross member must be added to the floor.

Driver door velocity

The give node on the driver door is measure for the velocity and plotted below.

Observation:

From the above graph we can see that the max velocity is 40mm/ms.

Conclusion:

• The intrusion in different zones of vehicle is plotted in graph. The intrusion in the fuel tank zone can be reduced by creating more cross members.
• The force passing through the crossmember is plotted.
• The maximum velocity of the door inner is found to be 40mm/ms.