Assignment 6

STIMULATION OF FRONTAL CRASH ANALYSIS OF NEON BIW

OBEJECTIVE:

To stimulate frontal crash analysis of Neon BIW by creating rigid wall and assigning the required parameters and derive various output as shown in the question.

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.

PROCEDURE:

• First, we have to check the unit of the system in the begin card in the model browser.

• We have to create the interface in solver browser – right click – inter with the required parameter, and select both the slave node as whole BIW and master element as the whole BIW.

• Then check the penetration by tool – penetration check.
• Then create rigid wall by right click the model browser – rigid wall – infinite plane and assign the parameters.

• Then compare the centre of gravity 300k node model by adding the mass on the BIW by clicking right the solver – admass – required node – mass.

• Then give the initial 15.6464 mm/ms velocity in the load collector right click create – load collector – interval.
• Then assign the time step 0.1 and run time in 80ms.
• Then create the cross section in the required BIW components by solver – sect – sect.

• Then create acceleration on the cross beam by right click solver – create – accel – required nodes.

• The assign inter, intevel, acceleration and section into the Time history (TH).
• Then create two nodes for the intrusion in the TH nodes and assign required skew in opposite nodes.

Von mises:

The von mises stress for frontal crash is 3.979e-01 N/mm2

SECTIONAL FORCE ON A-PILLAR:

The sectional force on A-pillar 1 experience 0.071KN at 34ms and section 2 experience 1.12 KN at 24ms because of the high stiffness A-pillar experience less force and also

the notches in the pillar absorbs some amount of forces.

SECTIONAL FORCE ON SHOT GUN:

The sectional forces on the shot gum region is 2.75KN at 53ms and 0.747KN at 36.5 ms the force in first shot gun is more than 2, because some amount of impact force is distributed

on the wheel archer holes.

SECTIONAL FORCE ON RAIL:

The force experience in first rail is 9KN at 55.5 ms and in second rail is 7.47KN at 74.4 ms, second rail experience less force because the two holes in that component reduce the impact force.

SECTIONAL FORCE ON HINGE PILLAR:

The force experienced on hinge1 is 2.115KN at 76.5 ms and in hinge 2 is 3.731 KN at 40ms. the hinge 2 experience more force than hinge 1.

SECTIONAL FORCE ON AXIAL:

The force experienced on axial 1 is 7.966KN at 14.5ms and axial 2 is 8.81KN at 12.5ms both axial experience compresive force at the time of impact which in the graph indicate high peak value.

ACCELERATION ON ROCKER:

The acceleration on two nodes of the rocker is 287.6 mm/ms2 and 287.6 mm/ms2 both accleration are equal because both nodes are exact opposite to each other during the impact the accleration increace rapidly after the impact it comes almost constant.

INTRUSION ON DASH BOARD:

In the intrusion the initial nodes distance are 767.575 mm and 779.432 mm after the impact both the nodes intruded into distance is 242.298 mm and 633.87 mm

ENERGY:

Kinetic energy is decreacing gradually while internal energy increase lineraly, the contact and hourglass energy remains constant.

RESULT:

Time - 9159.59 s

No of cycles - 80001

Internal energy - 38095 J

Energy error - 0.4%

Mass error - 0.3453E-01

Sectional force on A- pillar - 0.071KN & 1.12 KN

Sectional force on shot gun - 2.75KN & 0.747KN

Sectional force on rail - 2.75KN and 0.747KN

Sectional force on hinge pillar - 2.115KN & 3.731 KN

Sectional force on axial - 7.966KN & 8.81KN

Acceleration - 287.6 mm/ms2 and 287.6 mm/ms2

Intrusion_1 - 242.298 mm

Intrusion_2 - 633.87 mm

https://drive.google.com/file/d/1x5sf-RWmfSXBmsvO5TCBO8uqmo2ozthM/view?usp=sharing