Department of Mechanical Engineering

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Analysis of Car Bicycle Crashes
Department of Mechanical Engineering
IIT Delhi
Suman Chandrawat 2001498 Varun Agrawal 2001266
Supervisors Dr Anoop Chawla Dr Sudipto
Mukherjee 25th Feb05
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Introduction

• Problem statement
• To establish correlation between the throwing
  distance of bicycle riders and various crash
  parameters in vehicle bicycle crashes.
• Methodology
• Deciding on configurations for simulations.
• Setting up simulation in Madymo.
• 200 configurations simulated.
• Analysis of results.

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Load deformation characteristics for car bonnet
Load deformation characteristics for car
windscreen
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Bicycle tyre mechanical properties
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Frontal Side Collision
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Variation in throwing distance with car velocity
(15km/h 65 km/h)
Bicycle velocity 10 km/h Impact at an offset of
-0.15 m from car centre
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Variation in throwing distance with offset
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Comparison of simulation results with crash data
reported by Otte
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Variation in throwing distance with point of
impact
Bicycle velocity 2.66 m/sec (10 km/h) Car
velocity 9.72 m/sec (35 km/h)
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Variation in throwing distance with varying
bicycle velocity
Car velocity 12.5 m/sec (45 km/h) Point of
impact at an offset of -0.6 m from cars centre
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Variation in throwing distance with varying
bicycle velocity Car velocity 12.5 m/sec (45
km/h) Point of impact at an offset of -0.3 m
from cars centre
Note that the bicycle velocity for maximum
throwing distance changes
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Throwing distance with and without braking
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Side Impact
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Variation of throwing distance with car velocity
Angle of approach 600
Head
Left hand
Left hand
Left hand
Right hand
Left hand
Left hand
Right hand
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• Throwing Distance Displacement of first point
  of contact
• Non uniform curves for low throwing distances
  (side impact)
• Changes in the first body part coming in contact
  with ground
• Alternate definition Displacement of a certain
  (most prominent) body part head, pelvis
• Same trends for the two body part in most of the
  cases
• Head suitable for calculating the throwing
  distance

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Variation of throwing distance with car velocity
Angle of approach 450
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Effect of pavement design
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Config 3
Config 2
Config 1
Right leg
Right leg
Right leg
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Variation with pavement height
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Variation with point of impact on car
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Conclusion

• The obvious conclusion that throwing distance
  increases as the car velocity increases,
  reinforced.
• Trends follow the frontal crash data reported by
  Otte.
• Significant variation in throwing distance with
  angle of approach and point of impact on the car.
• Large variations in throwing distance for
  different configurations for same car velocity.
• Smaller throwing distances for side impact as
  compared to frontal impact.
• Non-monotonic changes with parametric variation.
• Alternate definition of throwing distance yield
  more meaningful curves.
• Cyclist dragged to larger distances in presence
  of pavements.
• Multibody simulations to be used for evaluation
  of injury patterns and safety measures like
  helmet, leg support, pavement and car bonnet
  design etc.

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Future Scope

• Finite element analysis to get the precise shapes
  and curvatures of various car and cycle parts.
• Dummy modification to reflect Indian population.
• Evaluation of safety measures using simulations.