Simulation and analysis of neon side crash BIW model using radios

Objective:

To perform Crash analysis on the neon side crash model and observe the sectional forces and displacements and energies

Procedure:

• For our model unit system is [Kg mm ms]
• We created the Type 7 interface with the following recommended properties

Istif =4 -> k= min(km,ks) ,Interface stiffness(k) is calculated from both master and slave characteristics

Igap =3 -> Variable gap + mesh size + scale correction factor

Idel =2 -> When one element is deleted corresponding master segment and slave nodes get deleted

Fscale_gap =0.7 -> Upto this value penetrations are neglected during simulation

st min =1 KN/`mm^2` -> Minimum stiffness value

Fric =0.2 -> Columb friction factor is taken as 0.2

Gapmin =0.5 -> Min gap for impact activation

Inacti =6 -> Initial penetrations are neglected and considered if it causes a problem during simulation

Iform =2 -> Stiffness formulation

• We create Type 7 interface( self contact ) for a model by selecting nodes as Slave nodes and elements as Master segments with all recommended properties
• Opened the model in hypercrash and check for penetrations and intersections and rectified in hypermesh

• Create a rigid wall of an infinite cylinder normal to the z-axis with (2250,1020,2000)

Dsearch=1000mm

Diameter=254mm

Fric=0.1

• Model weight is equal to the full-scale model weight of 700 kg and COG lies on seat reinforcement
• To get 700 kg and COG on the driver seat reinforcement added mass to the entire model and at rails

• Took initial velocity as 15.646mm/ms in y-direction because impact happens in this direction and run the simulation for 80ms with a frequency of 5
• Checked for errors by using the model checker
• In properties, we use Ishell =24 i.e., QEPH formulation because it does not form hourglass it has correction factor within the formulation
• Material properties are taken as default that gave in model i.e., M1(elastic ) and M2 (plas_johns) materials

Output requests:

• Created TH card for interface to observe sectional forces
• Created TH card for intrusion on B-pillar, Hinge pillar and fuel tank region i.e., on the rocker arm to observe displacements by picking nodes
• Created TH card to observe peak velocity of the inner node of the door by picking 337773 node
• Created cross-sections on the driver seat reinforcement and rail to observe the sectional forces

Image of the complete side crash model with all required sections

Simulation and results:

von mises stress for neon side crash model

• Von mises stress for this model is 0.374KN/mm^2
• A low value of von mises stress is good for simulation

Graphs and analysis of results:

Graph for global variables

• Internal energy keeps on increasing because as elements undergo deformation absorbs energy and stored as internal energy
• Hourglass energy is nearly zero because of Ishell=24 (QEPH formulation)
• There is a small increase in contact forces due to penetrations during the impact
• It takes about 10351s and 160001 cycles and energy error is about -2.6% which is acceptable
• A negative sign indicates dissipation of energy and this error includes contact and hourglass energy
• Mass error is 0% which is acceptable and results in the best simulation
• Max Internal energy is observed as 0.2959E+05 and Kinetic energy is observed as 0.5939E+05

Graph for R-wall forces

• The peak reaction force is 77KN at 0-5ms where model hit the rigid wall with initial velocity of 15.646 mm/ms
• A decrease in the graph is due to the formation of bends and increase is due to the resistance force offered by the rigid wall against the load application

Sectional forces on the cross-members:

Sectional forces on the cross-members

• Max sectional force on the seat reinforcement component is 2.47KN at 15-20ms
• Max sectional force on the mid rail component is 3.5KN at 35-40ms
• The difference in the cross-sectional forces is due to the difference in cross-sections and end conditions
• Seat reinforcement is fully covered by the rocker but mid rail is not fully covered

Intrusions at B-pillar, Hinge pillar and fuel tank region:

Intrusion on the fuel tank

• The intrusion of the node on the fuel tank is 270mm

The intrusion of the node on the Hinge-pillar

• The intrusion of the node on the hinge-pillar is 665mm

The intrusion of the node on the B-pillar

• The intrusion of the node on the B-pillar is 350mm

Peak velocity of the inner node of the door:

The peak velocity on the inner node of the door

• The peak velocity on the inner node of the door is 16.22mm/ms at 5-10ms

Conclusions:

• To reduce the intrusions of the fuel tank one can introduce New energy-absorbing materials to obtain crash-resistant fuel tanks
• Max sectional force on the seat reinforcement component -> 2.47KN
• Max sectional force on the mid rail component -> 3.5KN
• The intrusion of the node on the fuel tank -> 270mm
• The intrusion of the node on the hinge-pillar -> 665mm
• The intrusion of the node on the B-pillar -> 350mm
• The peak velocity on the inner node of the door -> 16.22mm/ms

Simulation and analysis of neon frontal crash BIW model using radios ->

https://drive.google.com/open?id=1z1MuE1a8L0OaNwOxxLcowhYqyIoYPqGi