Frontal Crash Analysis with Guidelines of FMVHSS 208 Standard by using Radioss

Frontal crash-BIW

• Check unit system and either follow[Mg mm s] or [Kg mm ms].
• Create appropriate interface ,friction 0.2 and recommended parameters.
• Make sure of no penetrations and intersection.
• Correct rigid bodies if any issues.
• Create rigid wall with friction 0.1.
• Compare the model weight with the full scale 300k nodes model and use added masses to reach target weight 700kg while getting CG about the required range.
• Initial velocity 35 mph.
• Use model checker to ensure good quality.
• Time-step :0.5 to 0.1 microseconds.
• Run 80 ms.

Output requests:

• Sectional force in the rails at location of indicated node 174247.
• Axial force received on the rails from bumper.
• Shotgun cross sectional forces.
• A pillar cross section.
• Acceleration curve received on the accelerometer at base of B pillar (on B pillar rocker).
• Intrusions on the dash wall 66695,66244.

SOLUTION:

• Import File neon_front_0000.RAD
• Open RAD File to check the unit system
• Unit system being followed is Kg | mm | ms
• Go to Model > Groups > Clear existing interfaces present.
• Create new contact > Include neon_front > Card Image as Type 7
• Use Recommended Crash application data,

• Select Master Elements and Slave nodes to the type 7 interface.
• Friction value as 0.2
• Go to Tools > Penetration Checker > Check
• Check for the errors present

• There are no errors present in the model
• To Correct rigid bodies if any issues.
• Tools > Find connectivity > Check

• There are 2 Free components present in the system , identified as Translational joint 1, TranslationaL_Joint 2 Spherical joint 1 & Speherical joint 2.
• Since those are free parts which is not required and can be cleared from the component
• To create rigid wall with friction of 0.1, go to Create > Rigid Walls.
• Using node, select the point to create reference point for the infinite plane.
• Use normal option to create the direction of the wall to act.
• Select Slide > Sliding with friction.
• Dsearch is used to induce the search distanct of the master to act upon.
• Input the friction value as 0.1

• To add mass to the model, target weight 700kg while getting CG about the required range
• Export file into radioss
• Go to Applications > Hypercrash
• set units as set in Hyper mesh as mm | Kg | ms > Run
• Click on added mass to view masses added on model
• To view COG , Go to Mass > Mass Balancing.
• To add mass Go to added mass section, Go to create new object
• Select Type 1 - Mass distribuited to each node of node group.
• In added mass input mass to be added, and select the nodes using selection.
• click save
• Go to Mass tab and click on view to preview COG

• Export the file as .RAD File to reopen in Hyper mesh

• To create the initial velocity 35 mph.
• Go to in Solver section > Boundary conditions > Inivel

• To change Time-step between 0.5 to 0.1 microseconds.
• Go to Model > Cards > ENG_DT_NODA

• To run Run 80 ms.
• To change Time-step between 0.5 to 0.1 microseconds.
• Go to Model > Cards > ENG_RUN

• To find Sectional force in the rails at location of indicated node 174247.
• Locate (Display Numbers) Click on node options type node ID 174247, press enter and turn on display
• Go to Solver tab > Create > Frame > Movinf Frame > Choose nodal point such that Z axis is normal

• Go to model tab > Set > Section 1 > Select the elements to be sectioned.

• Go to Create > Section > In cross selection, select the nodal points placed in frame > select frame ID

• Go to Time History > Create >Section > Select entity as Rail section
• Follow this procedure for all the cross section to be made in, shotgun section, Rails, A pillar.

Rail cross section

• To find Shotgun cross sectional forces.
• Go to Solver tab > Create > Frame > Movinf Frame > Choose nodal point such that Z axis is normal in short gun region
• Go to model tab > Set > Section Shot gun > Select the elements to be sectioned.
• Go to Create > Section > In cross selection, select the nodal points placed in frame > select frame ID
• Go to Time History > Create >Section > Select entity as Section shot gun

• To find A pillar cross section.
• Go to Solver tab > Create > Frame > Movinf Frame > Choose nodal point such that Z axis is normal in short gun region
• Go to model tab > Set > Pillar cross section > Select the elements to be sectioned.
• Go to Create > Section > In cross selection, select the nodal points placed in frame > select frame ID
• Go to Time History > Create >Section > Select entity as Section pillar cross section

All the sectional Frames

• To create Axial force received on the rails from bumper.
• Go to Model > Groups > Create
• Card type as Type 7 > Select Bumper parts as Slave nodes > Other components apart from bumper as car.
• Go to Solver Tab > TH > Select Entity > Axial contact.

• Acceleration curve received on the accelerometer at base of B pillar (on B pillar rocker).
• Go to Model tab > Create > Accel
• Place a node on B pillar on which accelerometer to be placed.
• Go to TH Create > Acc > In entity select Accelerometer > Right Side ACC

• Acceleration curve received on the accelerometer at base of B pillar (on B pillar rocker).
• Go to Model tab > Create > Accel
• Place a node on B pillar on which accelerometer to be placed.
• Go to TH Create > Acc > In entity select Accelerometer > Left Side ACC

• Intrusions on the dash wall 66695,66244.
• Using Temp nodes > create node using ID > Add nodes
• Go to Solver > TH > Nodes > Specify for displacement > Select the nodes

Go to model checker > Check for defects

• Go to Tools > Model checker
• Click check option to Run the scan
• clear the parameters that failed.

Ensure there are no errors founds in Model Checker.

OUTPUT SCREEN:

HYPERVIEW SIMULATED OUTPUT :

• The above is the simulated output of crash environment in which BIW is getting crashed upon rigidwall created.

FORCES ACTING AT SECTION - RAIL NODE :

• The force acting on Right rail is greater than left Rail from the output graph.
• The peak force is of approx 3.8KN at 55ms on Left Node.
• The Peak force is of 12.1 KN at 55 ms on Right Rail.
• The simulation shows the deformation of the rails which passes the forces through the body, the negative force is due to change of the mov frame direction.

• The force acting on Left is greater than the right shotgun.
• The peak force is of 7.5KN at 65ms on Left Rail.
• The peak force is of 2.8KN at 65ms on Right Rail.
• The negative energy is due to impact of components on wall.

• The deformation in the A Pillar left is more than that of Right pillar.

• The Peak force is of -50KN at 15ms.
• The deformation occurs in -x , hence the force is of negative value.
• The self contact with the rails bumper gets deformed in global -X

• The peak acceleration at Right side base of b pillar is of 6mm/ms.

• The peak acceleration at Left side base of b pillar is of 12mm/ms

• In this the intrusion of the node (66244) is of 900mm.
• The intrusion of node (66695) is of 860mm.
• The displacement is gradual along 80ms.

ENERGY PLOT:

• The Contact energy gradually increase to max of 200, as the component gets crashed, elements and nodes comes in contact with each other.
• The Total energy is decreasing as there is an energy error in the component.
• The kinetic energy found to be max due to the initial velocity, it decreases to 900 as the deformation happens.
• Internal energy increases from zero to max of 5250.
• Hour glass energy is of 12.62, very minute which affects the total energy.

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