Assignment 6-Frontal Crash Simulation Challenge

AIM : SIMULATION OF FRONTAL CRASH CAR WHERE THE STRESS ARE WROKING ON IT

Frontal 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 penetrations and intersection.
• Correct rigid bodies if any issues.
• Create rigid wall with friction 0.1.
• Compare the model weight with the full scale 300k nodes model and use added masses to reach target weight 700kg while getting CG about the required range.
• Initial velocity 35 mph.
• Use model checker to ensure good quality.
• Time-step :0.5 to 0.1 microseconds.
• Run 80 ms.

Output requests:

• Sectional force in the rails at location of indicated node 174247.
• Axial force received on the rails from bumper.
• Shotgun cross sectional forces.
• A pillar cross section.
• Acceleration curve received on the accelerometer at base of B pillar (on B pillar rocker).
• Intrusions on the dash wall 66695,66244.

Objective 1 :

>step 1 - Import the model as given radioss file 000.rad file

>step 2 - Now go with import model>cards as seen in the unit system

>Then now seen and any further changes in the units system as per given question I am following the units mass_unit=kg,length_unit=mm,time_length=ms

Objective 2 :

>Step 1 - Go with create>contact/interface/groups

>Step 2 - Now the changes of the recommended parameters then assigned it

>Step 3 - As per the given question the friction value is 0.2

>Now click on new create an interface and makes changes parameters

>After making changes

>As we go >Type 7>Igap=2,Inacti=6>Istf=4>Idel=2

>Objective 3 :

>step 1 : checking of penetration and intersection Tools>Penetration check

>Objective 4 :

>There is no any issues finds on the rigid body(RBody)

>OBjective 5 :

• Creating a rigid wall with friction 0.1.

>Step 1 : Firstly we have a locate point node on the which position to create rigidwall

>Step2 : Then go with >create>rigidwall

>Step3 : And the gives the axis of direction x,y,and z , I will place a node on a in front of the bumper plate and I locating x-axis so that I took of -1,y=o,z=o

>See here the direction is showing on

>Objective 6 : Adding the mass on the rigid body car component to increasing the car weight (And which was given 700kg)and while about required center of gravity CG range

>Step 1 : Solver>create>ADMAS

>Step 2 : And now create a cog on the car part and select the node at a middle of cog

>While balancing the mass weight

>Adding and minimizing the nodes to balancing the mass weight unstill required mass weight

>To know how to check up the Cog :

>

>Now finally created the cog point on the car part :

>THe Total mass And cog :

>Objective 7 :

• Initial velocity 35 mph as given in the question

>Step 1 : Go with create>Bcs>IniVel

>At gmd_Id click on the right click

>Then we have to give the velocity to the whole component and as given velocity value 35mph and converting then 35mph to 15.67kph

>By nodes option selected all displayed nodes at that at collect all components nodes

>Finally gives the proper value to assign the velocity

>Objective 8 :

• Time-step :0.5 to 0.1 microseconds

>Step 1 : To check the Anim/Dt > time freq(0.5)

>Objective 9 : Engine run time (80)

>Output request

>Objective 10 :

• Sectional force in the rails at the location of indicated node 174247

>Step 1 > Tools>Number>by id>display

>Now create the Frame card in the solver browsers :

>Step 1 : Create>frame>mov

>Now givies the origin and x-axies ,xy-plane :

>

>Finally created of the frame /mov

>Now creating the crosssection (section)

>Step 1 : slover>crete>sect

>Then assign values to the creating on the rail component

>Now crate the grshell_id (Element selected 2 or 3 rows all)

>Objective 11 :

• Axial force received on the rails from bumper.

>Step 1 : creating of the frame ,grshel,section

>Step2 : Create as above as same frame

>

Now crate the grshell_id (Element selected 2 or 3 rows all)

>Creting of the section on the rail from bumper

>Finally created frame and section on the bumper plate

>Objective 12 :

• Shotgun cross sectional forces

>creating the section on the short gun part

>Again same of creating the frame

>creating section on the shotgun leftside

>Objective 13 :

• A pillar cross section

>creating section and frame on the pillars A and B

>Now crate the grshell_id (Element selected 2 or 3 rows all)

>Creating frame

>Creating the section :

>And finally created on the pillar cross-sectional and frame/mov

>

>Objective 14 :

• Acceleration curve received on the accelerometer at base of B pillar (on B pillar rocker)

>Now creating the accelerometer on the pillar B

>And now selected of the node on the pillar B to created of the accelerometer

>Objective 15:

• creating Intrusions on the dash wall 66695,66244

>Now click on 123 option on the screen display then>select node>by id>66695

>Now see the number of intrusion point

>Same as the second part number 66244

>AND FINAL GIVES THE OUTPUT BLOCK PARAMETERS

>Which we are created then assigned to the outblock

>Created and assigned to the outputblock

>Creating the interface part /group

Type 7: Type 7 card is used to simulate all types of impact between a set of nodes and master surface. Main advantage of type 7 is stiffness is not constant and increases with the penetration preventing the node from going through the shell midsurface.

Istf 4: Stfac and stiffness is computed from both master and slave characteristics.

Igap 2: variable gap + gap scale correction of the computed gap.

Idel 2: When a 4-node shell, a 3-node shell or a solid element is deleted, the corresponding segment is removed from the master side of the interface. It is also removed in case of explicit deletion using Radioss Engine keyword /DEL in the Engine file. Additionally, non connected nodes are removed from the slave side of the interface.

Stmin 1: minimum stiffness (N/M)

GAPmin : Minimum gap for impact activation.

Inacti 6 : Gap is variable with time but initial penetration is computed .

Iform 2 : Stiffness (incremental) formulation.

SIMULATION OF THE FRONTAL CRASH : Simulating and analysing car’s frontal crash.

STEP 1: Open Hyperworks in Radioss solver.

STEP 2: Import Solver desk Project_1_0000.rad file

STEP 3: Simulating model as it is.

*Analysis>Radioss>save as Project_1_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_1.h3d file and T01 file

>The animation file obtained

>Next the open of 0.0001 rad file in the notepad which are obtained of no of cycles and we know of seen in maximum output results were of energy errors

>The performing of simulation were of last cycle energy errors are obtainted of :

>Energy error = -0.4%

>Internal energy = 0.3774E+05

>Kinetic energy = 0.4869E+05

>External work =-822.5

>Mass error = 0

>Total number of cycle =79900

>And finally seen all combined views :

>AND finally result of frontal crash :

EXPLANATION :

>KINEMATIC ENERGY :

Kinetic energy is the energy an object has because of its motion. After work has been done, energy has been transferred to the object, and the object will be moving with a new constant speed. The energy transferred is known as kinetic energy, and it depends on the mass and speed achieved.

The equation of kinematic energy = 1/2mv^2

>While applied to the velocity to the component,the intinally velocity too high and velocity is decreasing with respect to the time , because of the deformation constants in the component

>So, kinematic energy is directly proportional to the velocity , that the reason while kinematic energy decreases gradually (as shown in the plot graph)

>The best example of energy transfer from an object as shown in below image:

>INTERNAL ENERGY : Mathematically U = Q-W,Here neglected the heat because we are in the solver,as from the internal energy are depends on the displacement. in the starting there is no displacement in the component. that's were the internal energy starts from zero. when its subjeted to acceleration there will be a displacement, the internal energy increases its the displacement also increases.that the reason from raise of internal energy curve as shown image in plot

>TOTAL ENERGY: As there is no potential energy is not ploted , therefore the total energy is directly proportional to the kinematic energy,where the kinematic energy decreases then the total energy also decreases

>HOURGLASS ENERGY: There will be zero deformation that why the elements are undergo an hourglass effects strain is not consider,because there will be no physical stabilization,so,that to balance the energy,artificial energy is required to control of hourglass that's hourglass,so there is a lot of hourglass energy needed

>Outputs Understand :

>The main purpose of simulation of the front crash simulation is to occupied of the safety and damage controls

>As created of cross-sectional, frames, intrusion and initial velocity and accelerometer

>Center of Gravity : The center of gravity (CoG) of an object is the point at which weight is evenly dispersed and all sides are in balance.

>Rigid Wall : Rigid wall is created in the HyperMesh because where the car is going to make collisions.

>Penetration: There should not be any penetration because nodes get penetrated in the element and cause failure in simulation, removal of penetrated nodes is necessary.

>Accelerometer: An accelerometer is a device used to measure acceleration of the body and speed of force in the car

>Intrusion: Intrusion is used to check that if the component is withstanding a crash making sure that the component does not fail.

>Cross sectional: To maintain the equivalent forces distribution in the car

>FRAME : It purpose of giving as the direction Frames are used only in notable options like imposed velocity, imposed displacement, TH/node etc

>SKEW: Skew is one type of reference coordinate system which helps in defining local quantities with respect to the global coordinate system

>Skew is one type of reference coordinate system which helps in defining local quantities with respect to the global coordinate system

>The example is the study of intrusions in the car through skews and crash simulations