Compatibility: Causes, Constraints, improvement and Evaluation Proposal

- Contrary to commonly accepted ideas mass plays no part in the way in which energy is distrulted between the two vehicles
o Only the stiffness, by way of deformation loads

- “ Two cars are compatible if they have the same EES (Equivalent Energy Speed) in a car-to-car crash”

- Impact is also more severe, in terms of speed variation (conservation of momentum) for lighter cars

Conclusions:

- All cars should have homogenous front end
- All vehicles should have minimum compartment force capacity (especially small cars)
- All vehicle should absorb a minium amount of energy before reaching self protection force. (Especially big cars)

• How far back can a secondary load path be positioned and still contribute significantly to improving a cars structural interaction.

• What makes good compatibility

o Structural interaction
o Stiffness matching
o Equal Compartment Strength

• What makes poor compatibility...