A: You ask about “reduction in delta v in a multiple vehicle rear-end collision scenario” and “whether or not there would be enough energy coming into the system after all the movement and damage to even get to the fourth vehicle's crush damage”
Multiple vehicle impacts on the structure of a vehicle presents many complexities.
- First because data/research related to damage analysis on the reloading of vehicle structures is limited…
if you look up Prasad and the NHTSA "reformulation" you will see a lot of multiple barrier impact tests on vehicle structures and they did many on rear impacts. You might find some good data points for rear impacts with multiple impacts.
I’m not sure I understand what another response to this meant by “Crush energy is mostly related to the restitution between the vehicles”
- the main amount of crush energy is due to the structural loading. I expect he meant in low speed impacts once you damage the vehicle the restitution on subsequent impacts will be lower since the bumper/structure is damaged.
- Damage analysis equates the barrier impact speed to the residual crush which is a ‘virtual crush stiffness’ relationship. Restitution is the energy feedback which is a source of problem with simple damage analysis since as we have said many times
“Restitution acts to reduce the residual damage while increasing the impact speed change”
Here’s information on restitution What is Restitution?
I expect no information on relative impact and rest positions? From that you might be able to run some form of simulation to do a trajectory analysis?