1. Crash AnalysisCrash Analysis Presented By Khushal Suresh Sawant TE-Mechanical Engineering Roll No-302D056 PRN No-72287091E Department of Mechanical Engineering Sinhgad College of Engineering, Pune - 41 [2022-23]

2. Introduction  In automobile design, crash and structural analysis are the two most important engineering processes in developing a high quality vehicle.  Crash simulation is computer simulation that simulates a destructive crash test of a car or a highway guard rail system in order to assess the car’s and its occupant’s level of safety.  The kinetic energy, or energy of motion, that a vehicle has before the collision is change into deformation energy at the conclusion of the impact, largely through plastic deformation (plasticity) of the automobile body material (Body in White) during a crash simulation.  The effectiveness of the automobile body or guars rail structure to protect vehicle occupants during a collision is determined by data received from a crash simulation.

3. How car crash test works Car to barrier impact  It is made to pull the vehicle with the wire and to run, and it is made to collide with the barrier or the vehicle.  As the car crash test system, the one of the general method.  WINCH : Lifting device consisting of a rope or chain winding round a horizontal rotating drum, turned typically by a crank or by motor. Car to car impact  It is made to pull with the vehicle wire and to run two at the same time, and the vehicle is made to collide with the vehicle.  It is possible to adjust to new standard by which the energy absorption when the car with a different size collides mutually is evaluated and “compatibility” (The NHTSA advocates it)

4. Role of dummies and its instrumentation  Crash test dummies are the kept as they are used as replica for human in a crash test. Dummies are made of materials that imitate human physiology.  Though dummies of different sizes are used, dummy weighing 172lbs(78 kg) and standing at 69 inches (5 ft. 9 inches or 1.75m) tall is the most frequently used in testing Major parts in dummy  Accelerometers: - Measure the acceleration in a particular direction. This data can be used to determine the probability of injury. Inside the dummy's head, there is an accelerometer that measures the acceleration in all three directions. There are also accelerometers in the other parts of the body  Load Sensors: - Inside the dummy are load sensors that measure the amount of force on different body parts during a crash. The maximum load in the bone can be used to determine the probability of it breaking.  Movement Sensors: - These sensors are used in the dummy's chest. They measure how much the chest deflects during a crash.

5. TaskTask  Use FE analysis to identify the crashworthiness characteristics of vehicle  To perform the following simulation for 80-100 ms:  a) 30 mph barrier head-on-impact – FMVSS 208 simulation and compare with any available NHTSA tests b) 30 mph into 30 degree oblique barrier impact on left side – FMVSS 208 simulation and compare with results from simulation (a)  In all cases, determine overall vehicle deformation every 15 ms, the crash pulse, barrier force, structural deformation force and aft engine and compare with available crush space, and check for intrusion into occupant space  Analyze all data and discuss its implication to occupant protection

6. FE Model Static Data  Total No of Nodes : 72771  Total No of Element = 54800  Velocity = 13.4X10^3 mm/s (for 30 mph case)  Contact definition : single Surface Automatic Contact for all component.  Total Mass of Model = 2089 kg  Total Energy should be : E=1/2*M*V*V=1080E+8  For 35 mph E=2.50E+8

7. Case1 : 30mph front barrier impact   A rigid wall is created such that there is a complete contact of the wall and the car. Car has the initial velocity of 30mph   Single surface Contact has been defined for all the components of the car.   Pre-processor-Hyper mesh 8.0   Solver-LS-Dyna.   Post-Processor - LS-pre Post.   The basic aim of the analysis would be to see the effects of crash on the passenger compartment.   Simulation Time = 0.1 sec.   Total Wall Clock time for run = 4Hr

9. Crash process analysis

10. Case2 : 30mph30degree offset impact  A rigid wall is created such that there is a complete contact of the wall and the car. Car has the initial velocity of 30mph,the wall is rotated to 30degree on the left side of the bumper  Single surface Contact has been defined for all the components of the car.  Pre-processor-Hyper mesh 8.0  Solver-LS-Dyna.  Post-Processor-LS-pre Post.  The basic aim of the analysis would be to see the effects of crash on the passenger compartment.  Simulation Time=0.1 sec.  Total Wall Clock time for run = 4Hr

12. Crash process analysis

14. Thank You