Ford B MAX - structural rigidity and safety
Discussion
A question for the auto bods out there ...
I find it interesting that the USP of this car seems to be the open access feature. Now considering so few cars don't have such a feature... would removing the door pillar impact upon the scuttle shake and the overall torsional rigidity of the car? Also, impact wise, doesn't the B pillar actually provide an anchoring point for doors... so that the removal of it is more likely to cause a side impact into the passenger cell?
I assume it's passed the relevant safety standards, but from an engineering pov, is this actually a case of style over substance, or is there really an engineering case for removing the pillar?
I find it interesting that the USP of this car seems to be the open access feature. Now considering so few cars don't have such a feature... would removing the door pillar impact upon the scuttle shake and the overall torsional rigidity of the car? Also, impact wise, doesn't the B pillar actually provide an anchoring point for doors... so that the removal of it is more likely to cause a side impact into the passenger cell?
I assume it's passed the relevant safety standards, but from an engineering pov, is this actually a case of style over substance, or is there really an engineering case for removing the pillar?
I saw the advert with the diver jumping through the opening and wondered the same thing about safety and structural rigidity, ford explain it to an extent:
http://m.ford.co.uk/Cars/B-MAX/Safety-and-security
http://m.ford.co.uk/Cars/B-MAX/Safety-and-security
Putting the B Pillar in the door will weaken the monocoque and reinforce the door.
The OP's concern over stiffness depends on how much the pillar contributed to stiffness in the first place. There is no way that putting it in the door will be as good.
Crash safety is different. If the door is reinforced then this could easily be as good overall as an unreinforced door with a B pillar in the car body.
Structural stiffness has little to do with crash safety, it affects handling up to a point and improves the feel of quality and solidity. In ft.lbs per degree most small spaceframe kit cars will be around 1000-2000, the Ultima has been reported as 3300, a backbone frame 2000-4000 (TVR 2650, 60's Elan about 4000), a mass produced monocoque 2000-20000 (lower for older convertible designs and higher for big estates and saloons).
Crash structures are about absorbing impact energy while protecting the space occupied by occupants. A stronger, or stiffer, structure can actually be worse! This is because the impact forces will not be absorbed as effectively. Reinforcements may be as much for ensuring that energy is dissipated over a wider area as they are for resisting crumpling and welds are sometimes designed to unzip, one spot weld at a time, to crumple in a predetermined way.
The OP's concern over stiffness depends on how much the pillar contributed to stiffness in the first place. There is no way that putting it in the door will be as good.
Crash safety is different. If the door is reinforced then this could easily be as good overall as an unreinforced door with a B pillar in the car body.
Structural stiffness has little to do with crash safety, it affects handling up to a point and improves the feel of quality and solidity. In ft.lbs per degree most small spaceframe kit cars will be around 1000-2000, the Ultima has been reported as 3300, a backbone frame 2000-4000 (TVR 2650, 60's Elan about 4000), a mass produced monocoque 2000-20000 (lower for older convertible designs and higher for big estates and saloons).
Crash structures are about absorbing impact energy while protecting the space occupied by occupants. A stronger, or stiffer, structure can actually be worse! This is because the impact forces will not be absorbed as effectively. Reinforcements may be as much for ensuring that energy is dissipated over a wider area as they are for resisting crumpling and welds are sometimes designed to unzip, one spot weld at a time, to crumple in a predetermined way.
TheTurbonator said:
Take a look at the movement of the rear door in the frontal impact. spaceship said:
Take a look at the movement of the rear door in the frontal impact.
More concerning, why on the frontal impact does the side airbag on the left hand side of the car go off but not the right? surely it should be neither for a frontal impact (although there is no harm in them going off anyway to protect peoples heads from bouncing against the window or something but if they are going to go off it should be both.I also had to lol at 0:50 when the windscreen wiper is flexing around in slow mo it just looks funny (not dangerous just made me chuckle)
rpguk said:
Although I am always a bit wary about how well a sliding door would work after an accident. I remember when the new Mercedes Taxis first showed up in London. I asked the driver how we I get out in an accident and he had no idea (they're motorised too)
The windscreen of all cars is designed to push out from the inside without much force. Similar problems are faced with many designs of car doors if the car ends upside down after a crash; gullwing, lambo scissor style, Ford GT40 e.t.c. The answer is usually exit through the windscreen.Gassing Station | General Gassing | Top of Page | What's New | My Stuff