Assignment 7-Side Pole Crash Simulation Challenge

Assignment 7-Side Pole Crash Simulation Challenge

Objective: Simulation of given car model with the given parameters for requested output.

Case Setup and Execution:

The given car model is first imported into Hypermesh from File -> Import -> Solver Deck

1) After importing the unit system is checked from Model Browser -> Cards -> Begin Card

2) After confirming the unit system, the interfaces/groups which are presented with the model are removed, so they don't cause any change when simulation is running.

This is done from Model Browser -> groups -> RMB -> create

The chosen contact is self contact and all the nodes and elements are chosen for this contact.

3) Then intersections and penetration test is performed from Tools -> penetration check -> Selecting the self contact group and Run.

The results shown with 0 collisions

4) Since no penetration are found, we then go for creating a Rigid wall from Solver Browser -> RMB -> create -> Rwall -> Cylinder with the parameters from the reference model.

The Rigid wall is shown with the yellow solid cylinder and yellow dotted line indicates the search distance given.

5) After creating the rigid wall, the mass of the given model is changed to 700 Kg by adding the appropriate mass from Model Browser -> Solver Masses and choosing the add mass nodes which are on the floorboard.

Before adding mass, COG of the model is checked with Tools -> Mass, COG and Inertia check

By checking the COG, the mass are added to make the COG at the center of the board.

6) After mass is balanced with the CG at required range, intial velocity is imposed from Solver Browser -> Create -> BCS -> INIVEL and choosing the whole model. The value given for velocity is with respect to the unit system of the model

Intial Velocity is given as 15.6 mm/ms.

7) Then for the section forces at cross members, a moving frame is created on the components of both the cross sections from Solver -> Create -> frame -> Mov

Here the nodes are chosen for origin, x-axis direction node and Y- axis direction node.

This the frame created on cross sections

Using this frames sections are created from Solver Browser -> RMB -> Create -> Sect -> Sect

Frame crated on Cross sections

 

Similar to Frame, the nodes N1, N2 and N3 are chosen to form a plane and choosing the Frame Id formed on the specific component, The grshel_id nodes are chosen as one element line on either sides of the node about which frame is formed.

The output Block is updated with theses sections as output.

8) Finally for intrusions for nodes at the B Pillar, Fuel tank and Hinge Pillar a moving Skew is made similar to frame as the intrusions are detected with respect to this local coordinate systems. Theses skew are made in line with these nodes and in local y axis direction intrusions are noted.

Similarly for the other nodes.

Similarly for finding peak velocity of given node, a moving skew is created and ouput file is requested for velocity.

After Assigning the ouput Block are done, the Run time is checked from Cards from Model Browser and Model Checker is launched to see any errors pop up.

From Tools -> Mode Checker -> Radioss Block

By confirming it by the Selecting the error, warning and Info with Run

No errors are detected, So the simulation is run by Analysis -> Radioss

Results:

The front_crush_0001.out file is opened to check the mass error and energy error

Energy error is < -5 % which is good and mass error 1.105 % < 5 % acceptable

So the plot are carried out.

 For the Results, h3d file is imported to Hyperview and Played.

 

The graphs are plotted in Hypergraph and here T01 file is imported.

Energy plots:

The KE is started at highest and is decreased and similarly Internal energy is increased.

The total energy remains almost constant, so energy is balanced and results obtained are acceptable.

Section forces on Cross members Dark Red:

Section forces on Cross members Violet:

Intrusions on B-Pillar node along local Y displacement:

Intrusions on Fuel Tank node along local Y displacement:

Intrusions on Hinge Pillar node along local Y displacement:

Intrusions on driver seat node along local Y displacement:

Velocity curve at inner node of the door:

Peak velocity came to be around 15.6 mm/ms which is about velocity given on the car body and it drops suddenly due to impact on rigid wall.

Conclusion:

Learned of creating Sections for sectional forces and Rigid walls.

Learned of forming frames and skew.

The Simulation of Side Crash is successfully simulated in Radioss 2021.