Neon Side Crash Analysis

Objective:

In this project we do the side crash test in given neon model by create the interfaces and assigning the recommended parameters to it. And then create Rwall cylinder for the given friction. To reach target weight of 700 kg add mass in the neon model. Then include initial velocity and do the crash simulation test for the given time, then check the output request.

Procedure:

• Check the unit system of the simulation in rad file and maintain it in any one of the standard given. For this assginment unit system followed Kg,mm,ms .
• In hypermesh import the side neon model through Radioss solver deck and at the same time open the model in hypercrash to check.
• For the given model create Type 7 interface. This is nodes to surface contact interface.
• Assign the recommended parameters to Type 7 interface,the recommended parameters are

Igap =2

Gapmin =0.5

Inacti =6

Istf =4

Idel =2

Iform =2

Fric =0.2

• Then check if there is any penetration or intersection present by using penetration checker, clear the penetrations manually with translate option.
• Create a cylindrical rigid pole in side of neon model which is near to B pillar with friction 0.1 in which the neon side model to get an impact.
• In the given model we need to get the target weight of 700 Kg by using admas option using \"type 2 Mass/Area - additional surface mass applied on the shell area\" and \"type 0 Mass is added to each node of node group. So CoG assigned in required range.
• Create Initial velocity for given neon model using invel from option boundary conditions in that apply given velocity 35 mph by convert into 15.65 mm/ms.
• For the given model time step is set to 0.5microseconds and run time set to 80ms.
• After creating and setting all parameters as per the requirment check once again then save radioss output to the required folder.
• Run the simulations, in that output check the simulation run without any errors.
• From the output file open h3d file in hyperview run the simulation and take screen of the cross sections.
• In that measure the intrusion for given nodes and plot the graph in hyperview.
• In hypergraph open T01 file then plot graph for cross sections and for energies.

Output Requests:

• To check sectional forces in the cross members of the model by using section option. These were the created cross sections in the members
• For section option local cordinates for each cross section is created by using frame system.
• After creating cross sections create output block to get out put for the created cross sections and create TH card to include the cross section in it to get the output in hypergraph too.
• To check the intrusions assign nodes in driver seat region, B pillar region and in fuel tanl region.
• Then to check the peak velocity of the inner node of the door by creating the node at the door and create Th card for output.

Results:

Sectional Forces in the cross members:

• This graph shows the force received by the cross members of the given model.
• Above graph the sec 1 ( mid rail) starts from 0.2 kn (approx) at 0 ms and due to impact, force received in the range 0 to 1.1 N by the elements it shows ups and down upto 55 ms then it\'s reach 1.95 kn at 57 ms.
• After from there it reduced and reach maximum of 4.45 kn at 70 ms and at the end of simulation reached 2.4 kn (approx).
• Sec 2 (seat reinforcement) that start from 0 that force received in the range 0 to 1.1 kn (approx) by the elements it shows ups and down upto 60 ms.
• Then it show ups and down, and reach the maximum of 1.55 N (approx) at 76 ms and at the end reached 1.3 kn (approx).
• That sec 1 received max force than sec 2.

Intrusion on Driver side:

• Instrusion on Driver side shows the change in distance between the nodes on left side rocker and right side rocker after impact.
• This is taken from hyperview and the graph by measure option in hyperview.
• In that before impact 1325 mm, after impact it reached 980mm.
• The global intrusion is 345mm.

Intrusion on B- Pillar side:

• Instrusion on B - pillar side shows the change in distance between the nodes on left side and right side of rocker below the B - pillars after impact.
• This is taken from hyperview and the graph by measure option in hyperview.
• In that before impact 1320 mm, after impact it reached 520 mm.
• The global intrusion is 800mm.

Intrusion on Fuel tank side:

• Instrusion on Fuel tank side shows the change in distance between the nodes on left side and right side of rocker after impact.
• This is taken from hyperview and the graph by measure option in hyperview.
• In that before impact 1310 mm, after impact it reached 395 mm.
• The global intrusion is 915mm.

Reduce fuel tank intrusion:

• Reducing the fuel tank intrusion by improving shape and material, also by adding cross member in rocker region.
• Using Advanced High Strength Steel AHSS it increase the strength.

PeaK velocity:

• This graph shows the Peak velocity of a node(337773) at inner side of the door of the given noen model.
• The peak velocity initially starts form 15.85 mm/ms (approx) at 0 ms and it reach maximum of 16.1mm/ms (approx) at 9 ms.
• The it gradually drecrease and maintain between the range 0 to 6 mm/ms, and at the end velocity reachs 4 mm/ms.

Energies Obtained:

• In this graph some of the energies absord during side crash are plotted.
• Internal energy starts from 0 and it maintain in 100 joule for 5 ms then it gradually increase from there and reach around 25000 joule (approx) it is increased because due to impact.
• kinetic energy start from 85000 joule and then it decrease to 59000 joule (approx) after the model hitting the pole.
• Contact energy starts from 0 and maintain upto 20 ms, then it gradually increased and reach it reach 1200 joule (approx) at the end.
• Hourglass energy maintained in 0 upto 58 ms and it slightly deviate at the end.
• Energy error = -1.7%
• Mass error =0.961%
• Time ellapsed = 3998.64 seconds
• If energy error is negative, it is due to energy dissipation.In case of under integrated elements, the hourglass energy can also explain a negative energy error.
• Both the energy error and mass error are in acceptable range.

Result:

Thus the simulation of side crash test of neon model done by the steps followed above.