Assignment 7-Side Pole Crash Simulation Challenge
SIDE POLE CRASH SIMULATION
OBJECTIVE
The objective of side crash analysis of neon BIW is to know how much sectional force is recieved in the cross member of neon BIW . And to know about intrusion of a model as well as peak velocity to inner node of the door.The other objective of frontal crash analysis of neon BIW is to create a globalcontact interface .Cylindrical rigid wall add masses to reach a target weiht of 700 kg while getting COG about the required range intial velocity of 20 mph .Finally creating cross section as well as intrusion
CASE SETUP AND EXECUTION
CHECK UNIT SYSTEM
We have checked the unit system in the neon_front_0000.rad file and we followed Kg mm ms throught the process
IMPORTING MODEL
The model is imported into to hypermesh Search - the neon_side_reduced_0000.rad file and import
CREATING INTERFACE
Create an appropriate interface with friction 0.2 and recommended parameters .Already a contact is defined in the model we have to delete that interface and to create a new interface TYPE 7 with recommended parameters
Igap = Determines how the size of gap is calculated
Gapmin = Minimum gap for activation for interface
In acti = Action to take if intial penetrations exist
Istf = Affects how the stiffness of the interface is calculated
Iform = Friction formulation
Stim = Minimum stiffness to use in the interface
Idel = Update for deleted elements due to failure
Recommeded Contact Parameters for interface TYPE 7
Istif = 4
Igap = 2
Fscale gap = 0.8
Inacti = 6
Gap_min = 0.5
Fric = 0.2
Iform = 2
NOW RUN THE PENETRATION CHECK
Make sure of no penetration and intersection .If there is any penetration correct it or simply use the gapmin value to reduce the penetration. Rigid body issuses if any issuses make them corrected by using hypercrash
CYLINDRICAL RIGID WALL CREATION
An obstacle like infinite cylindrical rigid wall is created at left side of the model with some parameters like friction = 0.1 Dsearch as 500 and diameter as 254
A cylindrical rigid wall is created by Solver - Create - Rigid wall - Cylinder - Ok then a dialogue box will open and assign the required values
ADDED MASSES
Intially the model has a weight of 166.3076kg we have to add mass to reach a target weight of 700kg to get the COG about the required range .We have to add the mass at the floor of the BIW in order to get the COG at required range
A wide variety of mass type option are available to add the mass we have to choose the option 1 for better results
INITIAL VELOCITY
We have to create a intial velocity in order to perform the crash . Generally we have to give a intial velocity of 20mph which is standard value according to the crash standards .As we have following the Kg mm ms units we have to change the 20mph to required value
TIME STEP 0.5 TO 0.1 MICRO SECONDS
We have to create a time step in between 0.5ms to 0.1ms .And we have created the respected values .Run time as 80ms and Treq as 5ms .Use the model checker to ensure good quality
CROSS SECTION CREATION
We have to create the cross sections to know the forces acting on that particular sections .We have to create section on the cross members of BIW model .
Go the solver - Create - Sec - Ok .Then a dialogue box will open
Before creating the cross section we have to create a movable skew at the respected location and add the skew in this dialogue box .Then select the elements around that skew in atleast two columns of elements through out all sides as shown. Select the grshel_id if we got the quad element at respected skew and select the grtria_id if we got the tria element at respected skew. Assign some values to that card such as ISave as 0 Delta T as 0.1 and Iframe as 12 perform the same method for the other components and create the required cross sections
CREATING INTRUSION
We have to create an intrusion on the B pillar at node of 123211 Hinge pillar at a node location of 123321 Fuel tank region at a node location 123362 to know the dislacement of the particular wall into occupant area .For the we have to create a fixed skew and make the respected node number in one position
PEAK VELOCITY AT NODE 337773
We have to know the peak velocity of inner node of the door for that we have to create node reference by using TH node .
CREATING OUTPUT BLOCKS
Finally we have to delete the already requested output block and create a new out put block for cross section intrusion at 123321 123211 123362 and peak velocity
RUN SIMULATION
After creating all required outputs in hypermesh we have to run the simulation by using radioos .Keep the export options as all run options as analysis run number as 1 options as nt 4
Elapsed time = 1923.78s
Energy error = -2.6%
Mass error = 0.15115E-01
Total Number of cycle = 80001
ENERGY ERROR Bascially energy error must be negative and decreasing .The error must be less than 15% at the end of computation as per the condition .If the error is below 15% than the results could be acceptable
At the end of compuatation the energy error is -2.6% and mass error is 0.1515E -01 .As per the condition the energy error is -2.6% which below the 15% and the results could be acceptable for further simulation and plotting of graphs
SECTIONAL FORCE IN THE CH CBN SEAT REINF FT COMPONENT
From above plot we can see that the maximum force in the CH CBN SEAT REINF is 2.32KN which is around the 68ms
SECTIONAL FORCE IN THE CH RAILS U MID COMPONENT
Above plot we can see that the maximum force in the CH RAILS U MID is 4.85KN which is around the 34ms
Intrusion at 123321 123211 123362
The purpose of intrusion to know the displacement of the particular wall into the occupant area
INTRUSION ON HINGE PILLAR AT NODE 123321
Before collision the distance between two point is 1311.042mm
Above plot the intrusion of dashboard is 489.261mm
INTRUSION ON B PILLAR AT NODE 123211
Before collision the distance between two points is 1308.091mm
After collision the distance two points is 502.110mm
Above plot the intrusion of dashboard is 808.981mm
INTRUSION ON FUEL TANK REGION AT NODE 123362
Before collision the distance between two points is 1309.662mm
After collision the distance between two points is 429.516mm
Above plot the intrusion of dashboard is 880.146mm
PEAK VELOCITY THE GRAPH SHOW THE PEAK VELOCITY AT AROUND 17.2mm/ms
RESULT
CONCLUSION
When a collision is take place a reaction force will generate from the cylindrical rigid wall which is generally called as kinetic energy .This kinetic energy has huge amountt of impact if it is taken by the passenger there is chance of injury . In order to over come this energy should be absorbed by the car component itself .From the plot we can see that there is a increase in internal energy and decrease in kinetic energy .By this we can say that the energy is absorbed by the components .The total energy reamins constant .So that kinetic energy is converted into intenal energy .
- The contact energy remains constant due to implementation at recommended parameters
- The hour glass energy is also remains constant due to use of recommended parameters
- From above intrusion we had noticed is the intrusion at fuel tank region is high when compared to others .In order to reduce the intrusion at the fuel tank region we can change the material which have good strength we can modify the design if required
- Finally we conclude is the crossmember which is nearer to the impact pole had recieved more energy when compared to other crossmember
LINK : https://drive.google.com/file/d/1Gf5zKSUP45tzJiod_xOMKNluvweUznak/view?usp=sharing