Assignment 7-Side Pole Crash Simulation Challenge

Objective :- 

Neon side 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 penetration and intersections.
• Create rigid wall with friction 0.1 as per referance model.
• Compare the model weight with the referance model and use added masses to reach target weight 700kg while getting CG about the required range.
• Initial velocity as shown in picture.
• Use model checker to ensure good quality.
• Timestep :0.5 to 0.1 microseconds.
• Run 80ms.

Output requests:

• Sectional force in the cross member.
• Intrusion at B pillar,hinge pillar and fuel tank region.Provide recommendation on what can help to reduce Fuel tank intrusion.
• Peak velocity of inner node of the door.

PROCEDURE OF OBJECTIVE 1: Checking the unit system and either following [Mg mm s] or [Kg mm ms].

STEP 1: Open the starter file neon_side_reduced_000.rad file, go to-

*Menu bar>file>import>solver desk>select .rad file>import

STEP 2: Checking unit system of the model

*Model browser>cards>begin card

 

PROCEDURE OF OBJECTIVE 2: Creating appropriate interface, friction 0.2 and recommended parameters.

*Model browser>groups>create group>

 

PROCEDURE OF OBJECTIVE 3: There should be no penetrations and intersections

 *Menubar>penetration check>select group>check

PROCEDURE OF OBJECTIVE 4: Creating a rigid Pole with friction 0.1.

STEP 1: creating Rwall go to-

*solver model>create>rwall>CYL

STEP 2: Rwall CYL parameters and friction

• We can see that the Rwall Collector has formed automatically in the Model Browser with all parameters given by us.

PROCEDURE OF OBJECTIVE 5:  Adding masses to reach target weight 700kg while getting CG about the required range.

STEP 1: Opening mass summary

*Menu bar>tools>mass details>mass,cog,inertia.

• We can see that the mass is less as it should be around 700 kg.

STEP 2: Adding mass to increase overall weight of the car

*Solver browser>ADMAS>create>extra mass>give GRNODE ID>select nodes>give mass value

 

• Now again check the mass summary as shown in step 1 to check if the mass of the car increased or not as per our requirement. If not, again add a few masses at some nodes as done in step 2.

• At final we can see that mass is reached around 700 kg

STEP 5: Checking CoG 

*Menu bar>tools>mass details>mass,cog,inertia>cog

• Initial COG

• Final COG after adding mass

• Here we got the coordinate number where the CoG lies.

 

PROCEDURE OF OBJECTIVE 6 :   Adding Initial velocity 35 mph.

STEP 1: Creating card

*Solver browser>create>boundary condition>INIVEL

STEP 2: Set GRNODE

*Solver browser>GRNODE>create>GRNODE>node>selcect nodes

STEP 3: Setting up INVEL Parameters

1 mile = 1.609mm

1 hour = 3.6ms

Vo = (35*1.609*10^6) / (3.6*10^6)

Vo = 15.64 mm / ms

• We can see that the INIVEL is added to the model.

PROCEDURE OF OBJECTIVE 7 : Running a model checker to ensure good quality.

PROCEDURE OF OBJECTIVE 8 : Time-step: 0.5 to 0.1 microseconds.

*Model browser>cards>eng_anim_dt>Tfreq=5.0

PROCEDURE OF OBJECTIVE 9 :  Running 80 ms.

*Model browser>cards>eng_run>Tstop=80.0

 

PROCEDURE OF OBJECTIVE 10 :  Sectional force in the cross members.

STEP 1: Creating FRAME card  in solver browser.

STEP 2: Giving Parameters to FRAME>MOV

*Solver browser>FRAME>MOV>give origin,axis,plane node.

STEP 3: Creating SECT card in solver browser.

STEP 4: Giving parameters with GRSHEL elements selections to Components

STEP 7: Giving Output Request in Model Browser.

PROCEDURE OF OBJECTIVE 11 :   Intrusion at Fuel tank region, B pillar and Hinge pillar.

• Fuel Tank Region

STEP 1: Creating a new local coordinate in SKEW collector of solver browser and giving origin,axis and plane nodes.

STEP 2: Giving Output Request in Model Browser.

• B Pillar 

STEP 3: Creating a new local coordinate in SKEW collector of solver browser and giving origin,axis and plane nodes.

STEP 4: Giving Output Request in Model Browser.

• Hinge

STEP 5: Creating a new local coordinate in SKEW collector of solver browser and giving origin,axis and plane nodes.

STEP 6: Giving Output Request in Model Browser.

 

PROCEDURE OF OBJECTIVE 12 :  Peak velocity of inner node of the door.

STEP 1: Creating a new local coordinate in SKEW collector of solver browser and giving origin,axis and plane nodes.

STEP 2: Giving Output Request in Model Browser.

SIMULATION OF THE FRONTAL CRASH :  Simulating and analysing the car's side portion crash.

STEP 1: Open Hyperworks in Radioss solver.

STEP 2: Import Solver desk Project_2_0000.rad file

STEP 3: Simulating model as it is.

*Analysis>Radioss>save as input Project_2_0000.rad file>Checkbox include collectors>Write (-nt 4) in options>Click Radioss

STEP 4: Switch to Hyper view 

STEP 5: Select local model and result Project_2h3d file

RESULTS AFTER CRASH :

To plot the graph we need to switch to Hypergraph,

*Toolbar>select application to Hypergraph 2D>select runnameT01 type file 

• Fuel Tank

 

• B Pillar

 

• Hinge

 

• Cross Section 1

 

• Cross Section 2

 

• Peak Velocity in the inner of the door.

 

• Energy Graph

 

• Number of cycles it takes, energy error, mass error and simulation time.

 

The output file shows us the number of cycle, energy error, mass error

Number of cycles	80001
Energy error	-3.2 %
Mass error	1.084 %
Simulation time	3453.95 s (00:57:33)

OBSERVATIONS AFTER CRASH :

• We saw in the animation that the most deformation took place in the middle pillar area and the stress is then passed to the side of the rest of the components.
• We observed that the impact of the crash is mostly at the middle pillar side door of the car and by looking at this we can say that the seating area of the driver and passenger will be also impacted which can cause severe injury to them. 
• The energy graph is shown of Internal energy, Kinetic energy, Contact energy, Hourglass energy and Total energy Vs Time.
• We can see that Internal energy increases with respect to time whereas Internal energy starts falling down from its peak as time increases.
• Contact energy and hourglass energy graphs have values near to zero and Total energy remains almost constant as time increases.

• Graph for section

We can see that the total resultant force in the section which was right below the Middle B_Pillar (cross section 2) has gone into more deformation value near to 10 after the side body get hit with pole whereas the section which is far from middle pillar (cross section 1) has gone very less deformation as compare to section 2 with value near near to 0.6

• Intrusion Graph for hinge(1), Fuel tank (125383) and B_Pillar (123410)

We can see in the figure that hinge region has more deformation as compared to B pillar and fuel tank region that is why resultant displacement of hinge is linearly increasing with respect to time. Then the B pillar has more deformation as compared to the fuel tank region and fuel tank has less resultant displacement.

• Peak Velocity in the inner side door :

The resultant displacement of peak velocity keeps on increasing to value around 475 with respect to time 80 s. It shows that the region at and near to the node placed for peak velocity goes on continuous deformation as the time increases.