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

Case setup and execution

• In the intial step the radios file is imported in the hypermesh window using the import option.
• Before importing the file in hypermesh open the .rad file in tex editor and check for the unit system , for this analysis we have used the kg mm ms unit system.
• Once the file is loaded in the hypermesh window , we need to open the model checker option and run the model checker for radios ,once the model checker run is completed we need to check for the any errors and if any error is found out we need to check it and remove it step by step.
• Now as per the details mentioned in the question we have to set the type 7 contact , for this we will create a group interface for all the assembly components and define all the neccesaary parameters and also assign the friction value as .2 as per the question.
• Then we need to check for the free components and penetration check , if there is any penetration available in the model then we have to go to translate panel and then move the nodes slowly to remove the penetration.
• Once these checks are done we will go to the model browser and then create the cylindrical rigid wall will friction value of 0.1.
• After the rigid wall creation we can go to ANIM_DT card in the card section and define the time step as required.
• Once these steps are done we will create a set and try to balance the mass of the system to 700kg and at the same time try to bring the centre of gravity to the mid portion of assembly using ADMAS in the solver browser.
• Once the mass is balanced we setup the run time to 80 ms as per the instructions.
• After these steps we will setup the model for the output request we will create the the cross section at the required locations using SECTand FRAME options in the solver browser .
• Once the sections are created at required two locations we will go to the output block in solver browser and create an output block for cross section and assign it to both the sections.
• After this we will again move to sover browser and create skew for the getting the intrusions at the fuel tank, bpillar and hinge pillar locations.
• Once the skew is created we will create the output block for all the three intrusions and assignig the required node and skew to it at the same time.
• After this step we will create a skew for calculating peak velocity at the inner node of the door , we will select the node from the skew location only in output request for defing the output card for peak velocity.
• Once all the steps are done we will do the basic chekcs in the model for quality and then run the model checker for Radios once , the model checker should be free from errors before proceeding for the analysis.
• Once it is confirmed that model checker runs are ok and free from error we will move to analysis window and select the desired path to save and run the file.
• Once the simulation runs are done we will check the output file for mass error and energy error , it should be under the desired range.
• After cheking errors we will go to hyperview window and plot the required contours for stress, strain etc and graph for the sectional forces , intrusions etc.

Images and Graphs

• Image showing the placement of cylindrical rigid wall for side impact.

• Contour plot showing the Displacement observed in the model.

• Contour plot showing the Plastic Strain observed in the model.

• Contour plot showing the Von-misces Stress observed in the model.

• Contour plot showing the Specific energy observed in the model.

• Graph showing the peak velocity observed in inner node of the door.

• Graph showing the intrusion observed in fuel tank location.

• Graph showing the intrusion observed in B-pillar location.

• Graph showing the intrusion observed in Hinge block location.

• Graph showing the cross sectional forces observed in cross member location 1.

• Graph showing the cross sectional forces observed in cross member location 2.

Result

• From the simulation file it was observed that the mass and energy error are 0.1139E-01 % and -2.0% respectively in the model and these values are in the acceptable range for the simulation .
• The total time taken for the analysis was 3770.30 s with toal number of the cycles of 80001.
• The max Von mises stress observed in model is 3.625e-1 kgmm-1ms-2
• The max Plastic Strain observed in model is 6.862e-1.
• The max Specific energy observed in model is 3.027e+4 kgmm2/ms2.
• The graphs with the value of cross sectional forces on two cross members are plotted.
• The graph for intrusion at fuel tank , hinge block and b-pillar location and peak velocity at the inner side of the door are also plotted as per the instructions.

Conclusion

Due to the limitation of the computation we have tried to mimic the full scale model with our current model with the copatibilty of the software version, for the same we tried to balance the mass of the assembly with a ful scale model of 700 kg.

From the graph valus it can be easily observed that the b pillar region is going under least intrusion , from this we can coclude that the b pillar region is designed in such a way that it is best fit for least intrusion thus providing safety to the passenger, as in case of side impact the major factor should be the safety of the passenger and any intrusion happening in the b pillar region should be avoided at any cost to ensure the safety of the passenger. To reduce the intrusion at fuel tank location we can try making the model more stiiffer in that region thereby reducing more intrusion.

Also during the entire simulation no major error or hourglassing is observed thus it can be concluded that the model result are satisfactory without any simulation error.

The process of this side crash simulation is of great importance as it plays a major role in defining the safety of the passenger scenario of a car undergoing side impact., from the simulation result it can be observed that the simulation performed is providing us with the satisfactory results as per our requirement.

Please find the link for the drive as i am unable to upload the file here due to file size.

link for the simulation files-https://drive.google.com/file/d/1mgqoQgvzwRj0v609s-beJbTWZyt3Zjgz/view?usp=sharing