1 / 28

ME 115: Dynamics of Materials

ME 115: Dynamics of Materials. Manuel Leija. Christian Reyes. to. Vehicle. Vehicle. Collision. To further understand collisions and the effects in different cases, three dimensional kinematic and dynamic force analysis is essential. Three. Car. Collision: 2D.

aquene
Download Presentation

ME 115: Dynamics of Materials

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ME 115: Dynamics of Materials Manuel Leija Christian Reyes

  2. to Vehicle Vehicle Collision • To further understand collisions and the effects in different cases, three dimensional kinematic and dynamic force analysis is essential.

  3. Three Car Collision: 2D • Assume two cars colliding perpendicular to each other, find the resulting forces and momentum after collision. • How would it affect another on-coming vehicle if hit?

  4. Three Car Collision: 2D • Solving the previous problems would seem easy for anyone, but in reality, there are a lot more factors to be considered.

  5. Solidworks Model of Truck

  6. Solidworks Model of Car

  7. Vehicle Data • Working Model: Truck=2900 lb and 45 mph, Car1=2200 lb and 25 mph, Car2=2200 lb and 25 mph, Coefficient of Restitution =1 • Nastran (unrealistic): Same as Working Model • Nastran (realistic): Same as Working Model but with a coefficient of friction=.5 between the road and the tires

  8. Working Model Simulation

  9. Working Model: 2D

  10. Equations: 2D • Car A: x = xo + v*t • Solved for time to collide with Truck using xo = 0 and x = 50 ft, and constant velocity vA = 25 mph (440 in/s) • Car B: (x – xo)B = vB*tA = (vB/vA)(x – xo)A • Solved distance that would cause collision using Car A as reference with xoB = 0 at vB = 45 mph (792 in/s)

  11. Other General Equations: 2D • Kinematics of Rigid Bodies • Position Analysis, Translation, Rotation • Kinetics of Rigid Bodies • General Plane Motion • Momentum and Impulse • Conservation of Energy

  12. Nastran 4D • Three dimensional kinematic and dynamic analysis made easy. • Similar scenario with only two vehicles. • Two different situations: • Unrealistic (frictionless surface) • Realistic (with friction)

  13. Unrealistic (No Friction)

  14. Linear Momentum Data

  15. Right Before Impact

  16. Bam!!

  17. Realistic (with Friction)

  18. Realistic (with Friction)

  19. Before Impact (with Friction)

  20. Immediately After Impact

  21. Basic Drop Test

  22. Maximum Contact Force (at h=2ft)

  23. Learning Experience • How to use modeling programs to simulate real life situations. • Use analytical techniques from class for solving problems. • Despite what most car manufacturers say, truth be told, do not roll your car!!!!  • It’s not just the car itself that damages the vehicle, it’s all translated energy also. • It’s all about impulse and momentum!!

More Related