Challenge

Assignment 7-Side Pole Crash Simulation Challenge

OBJECTIVE:

Intially set up the model for side crash, by creating rigid wall with given friction
Create Interface with suitable parameters and friction = 0.2
Check for the penetration and intersections
Check the model by Model checker
Create sections and intrusion in mentioned place
Create respective output blocks

Steps carried out:

Check for unit system

Open the 0000.rad file in notepad and look for the unit system used
We can see the unit system used in themodel from above picture , same will be used in our simulation

Create interferance

Penetration checks

Rigid body Check

Rigid wall creation

For the side crash analysis we have to create a rigid wall of cylinder type
To create the same go to Solver>right click create>Rwall>CYL
Select the nodes from B pillar, we have to make sure the pole created should cover the whole height of the car
D search=1000; Cyl Dia=254mm; rigid wall will be created, the cylinder should not be in contact with the car maintain some gap

Create initial velocity card

To create initial velocity open the model in hypercrash
go to load case>initial velocity>select all the nodes , specify the direction of velocity
Give the velocity value as 15.6464(Same like frontal crash) in the y direction

Balance the mass and COG

To see the mass and cog of current model go to mass>balancing
From the above image we can see the total mass as 166kg,and the cog point is not in required position
By comparing the model with full car model we have to change the cog point and mass has to bte increased to 700kg
To add the the mass go to load case>added mass>add the mass wherever required
Here i am using type 1 mass addition, where the mass added will be equally distributed to all the nodes
From the above image we can see the total mass = 700kg and cog is in desired location
Export the file and open it in hyperworks, from now the steps can be carried out in hyperworks

Mention termination time(Tstop) and Time step

Go to solver>engine keywords>run>T stop= 80ms
Go to solver>engine keywords>DT>DT NODA>give T min(minimum time step) value
Go to solver>Engine keywords>Anim>Anim DT>Give T frequency value, this Tf value will decide your number of frames generated

Output Requests:

Create Sections

As metion in question we hav to create sections in cross member to obtain the results
Before creating section we have to create frames for the sections
To create frames go to solver>right click create>frame >Mov, selct all the N1,N2,N3 nodes
To create section go to Solver>Right click create>SECT
In section card, give delta T=0.1; alpha =1.94; Iframe=2;
Select the frame id of previously created frame, select the same N1,N1,N3 nodes which you have selected to create frame
gr shell id = selct the elements in the section
After creating the section card to extract or to plot the results of the section force, we have to create output blocks
Go to model>output blocks>right click create
Create a section card by changing the entity ID into cross section and select the respective cross section card
Do it for both cross member

Create Intrusions

Create intrusion at mentioned node
Go to solver>TH>Right click create Node
Select the node where the intrusions has to be created
Same way create a node card for peak velocity at node 337773
Now all the set up are done we have to run the simulation
Go to analysis>Radioss>options= -nt 4> save the file in desired location> run the simulation by clicking radioss

RESULTS and Discussion

The total ellapsed time , number of cycles is shown in below image
Now open the output file from the location you saved the file, we can see the energy error
From the above image we can see the energy error = -2.3%, which is acceptable
Now we can open .h3d file in hyperview
Displacement=1.465E+03 mm
Von mises=3.686E-01
Section force of Cross member 1

Resultant Normal Force=1.112262
Rsultant Tanget Force=3.279397
Section force of Cross member 2

Resultant Normal Force=6.684824
Rsultant Tanget Force=16.377491
Intrusion Fuel tank

Resultant Displacement=314.571mm
Intrusion B pillar

Resultant Displacement=2499.578217mm
Intrusion Hinge pillar

Resultant Displacement=546.63587mm
Peak velocity @ node 33773

Resultant velocity:
Maximum=15.911763 mm/ms
Minimum=1.299031 mm/ms

Resultant Displacement = 331.384583 mm
Internal Energy=28958.126953 kg*mm2/ms2

Kinetic Energy
Max=85965.906250 Kg*mm2/ms2
Min=54622.148438 Kg*mm2/ms2

Contact Enenrgy=1820.312256 Kg*mm2/ms2
From the above graph the kinetic energy is decreasing with respect to time
Internal energy is increasing with respect to time

CONCLUSION:

The model is set up for side crash with required interface and with no intersections
Created sections in cross members to get the section force result
Created Intrusion at required nodes and get the respective results
Created the output blocks for sections to plot the results in Hypergrpah 2d

Ship work like this
in your own course.