Crashworthiness and Occupant Protection in Transportation Systems I ME 8020 Test No.1

Crashworthiness and Occupant Protection in Transportation Systems IME 8020

Test No.3

ROOF CRUSH OF Truck

Presented By: Suravi Banik (fz4276)

Objective of the Test

Roof crushis the failure and displacement of an automobile roof into the passenger compartment during a rollover accident. The relationship between injury levels and intrusion orroof crushhas been statistically established, but the mechanism has been thought sometimes to be somewhat obscure.

In the early 1970's, the National Highway Traffic Safety Administration (NHTSA) was responsible for the United States becoming the first country in the world to address deaths and serious injures associated with vehicle roof crush. Federal Motor Vehicle Safety Standard (FMVSS) No. 216, "Roof Crush Resistance," became effective on September 1, 1973.

The purpose of the standard is to reduce deaths and injuries due to crushing of the roof into the passenger compartment area in rollover crashes.

Roof Crush Conducted

TruckWith 95th percentile dummyRigid wall according to FMVSS

Model Description

Car Model Selected:

1.C1500 Pick Up Truck (NCAC V4); Weight of the truck= 1716.97 kg

3.Dummy: 95th percentile Dummy (weight: 79 kg)

Full model (Truck_Rigid Wall_Dummy)

ProcedureOriginal Model runChecking original model of any initial errorsFull model run (vehicle airbag dummy)Including airbagConnecting beamsChecking consistency of unitsPositioning dummy Attaching the Rigid wallTest results

Roof Crush CriteriaDisplacement applied 127 mm/.127 mEnd time .127 secRigid wall length 1829 mm/ 1.829 mRigid wall width 762 mm/.762 m

Roof Crush of truck

25 ms50 ms75 ms

Roof Crush of truck100 ms127 ms

Roof Crush of truck

Energy plot (ROOF CRUSH)

MATSUM

z-displacement vs time

Node 50115398 was selected and analyzed for the deformation of the roof and a Graph of Displacement vs Time was plotted

Normal Force vs time

What if :Trial 1 (Applying displacement 0.5 m and endtime 0.15 sec)

What if :Trial 1 (Applying displacement 0.5 m and endtime 0.15 sec)

150 ms

GSTAT data and Matsum

Z-displacement and Force vs time plot

What if :Trial 1 (Applying displacement 0.5 m and endtime 0.1 sec with spc)

What if :Trial 1 (Applying displacement 0.5 m and endtime 0.1 sec with spc)

100 ms

GSTAT data and Matsum

Z-displacement and Force vs time plot

What if :Trial 1 (Applying *parameter)Increasing the roof thickness and applying ultimate strength

Observation

Disp.127 m and end time 127 ms according to FMVSSApplying Disp. 0.5 m and end time 150 msApplying nodal constraints

Applying parameter (increasing thickness of the roof and ultimate strength)

Observation

Disp .127 m and end time 127 ms according to FMVSS

Applying Disp. 0.5 m at time 150 ms

Observation

Applying nodal constraints

Applying parameter (increasing thickness of the roof and ultimate strength)

Conclusion

According to FMVSS as we see from the simulation, the roof is crushed due to 0.127 mm displacement appliedFor what if trial 1 when we applied more displacement the deformation is more visibleFor what if trial 2 when we applied nodal constraint the dummy tends to move down to the floor and the roof is not so much crushed as trial 1For what if the thickness of the roof is more and ultimate strength is used as a parameter, the deformation is less and the injury of the occupants will be less.

Improvements can be done

As the roof and hood are more prone to deformation we should increase the thickness of the roof or we can do some structural improvements like adding beams to the roof which will decrease the deformation and damage to the occupants.