Crashwortiness and Occupant Protection


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this is the presentation that me and my friend presented in crash wortiness and occupant protection.

Crashwortiness and Occupant Protection

  1. 1. ME-8030 Crashworthiness and occupant protection in Transportation System –II Side Impact Regulations and Analysis of 1993 Ford Taurus Model <ul><li>Presented to- </li></ul><ul><li>Dr. Taufiq Khalil </li></ul><ul><li>Dr. Cliff Chou </li></ul><ul><li>Presented by- </li></ul><ul><li>Kulbir Singh Dhillon </li></ul><ul><li>Varun Gulati </li></ul>
  2. 2. Side impact <ul><li>It is referred to an impact occurring anywhere along the side of automobile, including fender (F), passenger compartment (P) and rear area (B). </li></ul><ul><li>Side impact is second most injurious and fatal among multi-vehicle crashes. </li></ul><ul><li>Side impact results 32% of the seriously injured (AIS 3+) occupants. </li></ul><ul><li>Chest is the pre-dominant injured body region followed by head and pelvis </li></ul>
  3. 3. Project Objective <ul><li>The objective of the project is to obtain vehicle crashworthiness test data for different types of side impact tests- </li></ul><ul><li>FMVSS 214 </li></ul><ul><li>IIHS </li></ul><ul><li>NCAP </li></ul><ul><li>And then comparing them with the actual data and velocity curves. </li></ul>
  4. 4. Finite Element Model <ul><li>Downloaded from GWU website </li></ul><ul><li>1993 Ford Taurus, Modified model (28,400 elements) </li></ul><ul><li>Weight of the model is 1378kg </li></ul><ul><li>Checked the penetration in hypermesh. </li></ul>
  5. 5. Illegal stress-strain curve error <ul><li>*** Error Part ID #     193 has an illegal stress-strain curve-Slope of curve exceeds Young’s modulus </li></ul><ul><li>Modified stress strain curve </li></ul>
  6. 6. Moving Deformable Barrier(MDB) <ul><li>Downloaded from ETA/VPG </li></ul><ul><li>Material -Aluminum honeycomb barrier </li></ul><ul><li>Bottom edge is 279 mm and bumper is 330 mm from ground. </li></ul><ul><li>Weight= 3015 lbs </li></ul><ul><li>No. of parts= 20 and no. of elements=6662 </li></ul><ul><li>The wheels of MDB are inclined at 27 degree </li></ul>
  7. 7. Side Impact Dummy(SID) Number of parts -62 Number of elements -12575 Number of nodes-17996 For a SID there are no arms and we can only move the feet's and legs or you can rotate the whole dummy. Using the H point or the reference point the dummy was placed on the seat.
  8. 8. FMVSS-214 Side Impact dynamic Test <ul><li>It involves –A moving Deformable Barrier(MDB) striking a stationary vehicle at 90 degree with all wheels rotated at 27 degree from longitudinal axis with 33.5 mph closing speed. </li></ul><ul><li>Initial velocity values and their vectors were modified </li></ul><ul><li>Defined Hourglass energy card and hourglass energy control card. </li></ul><ul><li>In order to check the deceleration and velocity we placed accelerometers, at the B pillar ,door, dummy, C.G of barrier and far side of the impacted vehicle. </li></ul><ul><li>we have run the model for 150 msec with time step of 15msec. </li></ul>
  9. 9. Setup and adjustment of MDB
  10. 10. Test setup of FE model MDB and SID <ul><li>First, we selected the lowest node point of the vehicle to get minimum Z-coordinate (z=0.08). </li></ul><ul><li>Calculated wheel base centre=1360.3001 and 37”=940mm as impact point from centre. </li></ul><ul><li>Then, Set model to rear view, and select a node from the left most position. This y-coordinate acts as the contact clearance calculation base. </li></ul><ul><li>After the MDB setup, ETA/VPG will ask about the default SID dummy and VPG prompts for the location of H-point of dummy w.r.t your FE –model. </li></ul><ul><li>H-point is the reference point on the dummy for user to locate it on the seat. </li></ul><ul><li>In this case we used x=1220.y=-383.4,z=430. </li></ul><ul><li>And at last we adjusted the dummy from rotation menu. </li></ul>
  11. 11. MDB Position for FMVSS-214
  12. 12. SID position
  13. 13. Impact after 150 msec
  14. 14. Dummy position at 75 msec
  15. 15. Video
  16. 16. Energy Graph
  17. 17. Lower Rib Peak Acceleration=77G
  18. 18. Upper Rib Peak Acceleration=56G
  19. 19. Lower Spine Peak acceleration= 80G
  20. 20. Pelvis Lateral Acceleration=129G
  21. 21. Results for TTI(d) and pelvis acceleration <ul><li>Gr = greater of peak accelerations lower rib= 77G’s. </li></ul><ul><li>Gls= lower spine peak acceleration= 80 G’s. </li></ul><ul><li>TTI(d) = ½(Gr + Gls) </li></ul><ul><li>=1/2(77+80) </li></ul><ul><li>TTI(d)= 78.5 G’s < 85 G’s for four door vehicle, </li></ul><ul><li>so it is acceptable. </li></ul><ul><li>Pelvis Acceleration <= 130 G’s </li></ul><ul><li>which in our case= 129G’s </li></ul>
  22. 22. Velocity v/s time graph for FMVSS-214
  23. 23. NCAP Side Impact Test <ul><li>Test procedure and model description for New Car Assessment Program (NCAP) is same as for FMVSS-214, accept the velocity of the MDB is changed from 33.5 miles/hr to 38.5 miles/hr. </li></ul><ul><li>MDB and SID Dummy models are same. </li></ul><ul><li>Accelerometers are introduced at the different positions of dummy, B -pillar and side impact door(on side impact beam and near window sill) </li></ul><ul><li>We run the model for 80 msec with time step of 15 msec. </li></ul>
  24. 24. Impact at 30ms
  25. 25. Impact at 80ms
  26. 26. Dummy position at 75msec
  27. 27. Video NCAP
  28. 28. Energy Graph for NCAP
  29. 29. Velocity v/s time graph for NCAP
  30. 30. Comparison of velocity curves of mid b-pillar and barrier
  31. 31. IIHS Side Impact Test <ul><li>Side impact crash tests consist of a stationary test vehicle struck on the driver’s side by a crash cart fitted with an IIHS deformable barrier . </li></ul><ul><li>The 1,500 kg moving deformable barrier (MDB) has an impact velocity of 50 km/h (31.1 miles/hr) and strikes the vehicle on the driver’s side at a 90-degree angle. </li></ul><ul><li>The longitudinal impact point of the barrier on the side of the test vehicle is dependent on the vehicle’s wheelbase. </li></ul><ul><li>The impact reference distance (IRD) is defined as the distance rearward from the test vehicle’s front axle to the closest edge of the deformable barrier when it first contacts the vehicle </li></ul>
  32. 32. Test Setup
  33. 33. IRD Calculation <ul><li>If wheelbase < 250 cm, then IRD = 61 cm </li></ul><ul><li>If 250 cm ≤ wheelbase ≤ 290 cm, then IRD = (wheelbase ÷ 2) – 64 cm </li></ul><ul><li>If wheelbase > 290 cm, then IRD = 81 cm </li></ul><ul><li>The wheel base centre of ford Taurus in our case = 272.06 cm. so we calculate </li></ul><ul><li>IRD = (272.06/2) – 64 cm </li></ul><ul><li>IRD = 72.06 cm </li></ul>
  34. 34. Videos for IIHS
  35. 35. Impact at 150 msec
  36. 36. Energy Graph
  37. 37. B-pillar deformation with respect to the reference point on centre of driver seat <ul><li>Boundary line Good Acceptable Poor </li></ul><ul><li>B-pillar to driver seat </li></ul><ul><li>centre line(cm) >= 12.5 5 to 12.4 0-4.9 </li></ul><ul><li>In our case its coming = 7cm(acceptable) </li></ul>
  38. 38. Comparison of velocity curves of FMVSS and NCAP FMVSS-214 NCAP
  39. 39. Conclusion and Discussion <ul><li>In FMVSS 214 the results are compared with the actual test and we almost manage to obtain the similar results to that of actual test results. TTI(d) injury criteria is acceptable for the model as it comes out to be 78.5G’s. The pelvis acceleration is also acceptable as it comes out to be 129G’s. </li></ul><ul><li>In NCAP the results were compared with actual velocity versus time graph and they turn out to be acceptable as there is marginal variation between the real and obtained graphs. </li></ul><ul><li>Accelerometers were placed on door panel, B-pillar, Dummy and far side of the struck car. An analysis was conducted of the accelerometers used in NCAP and FMVSS test and it was determined that many of the accelerometer survived the crash test and produce satisfactory signals. </li></ul><ul><li>In IIHS test the barriers hits the car at 31.1mph and the B-pillar to centre of the driver seat deformation is calculated and comes out to be 11 cm which is acceptable. </li></ul><ul><li>The energy plots in all the three tests are balanced. In the energy plots as the kinetic energy drops the internal energy increases and thus after sometime they become constant. The total energy and the hour glass energy remain constant in our tests. </li></ul>
  40. 40. References <ul><li>  ME 8030 – Crashworthiness and Occupant Protection in Transportation Systems II lecture notes </li></ul><ul><li>An analysis of NCAP side impact crash data, Husan Chan. National highway traffic safety administration. United States </li></ul><ul><li>Side Impact Crashworthiness Evaluation Crash Test Protocol (Version V) </li></ul><ul><li>Ls-Dyna 970 Keyword Manual </li></ul><ul><li>Ls-Dyna 970 Theory Manual </li></ul><ul><li>ETA/VPG Safety Tutorials </li></ul><ul><li>NHTSA website </li></ul><ul><li>IIHS website </li></ul>
  41. 41. <ul><li>THANK YOU </li></ul>