Car Safety Graduation Project

you can use shock hydraulic absorber as in railway. use it in bummer i think it it greatly help you.

I looked it up. It seems like a good idea. Quite feasible and cheap to use too.

How do you suggest I use it though?
Should I actuate the absorbers forward and lock them in position before an impact? Or should I leave it as it is and connect it to a metal frame bumper, like the ones people attach to their 4x4 Cars and Minivans?

Another question, how can I calculate how much energy it can absorb, along with the energy a crumple zone can absorb? I've been looking for data regarding crumple zone absorption but I can't find any numbers.
I'm liking CE already. 😀

Hi people,
Just stumbled across this discussion. Just want to ask something. Don't you think the shock absorbers of railway will be heavy and hard to get?
Think practically. Use most feasible things for project. Correct me if I am wrong.

I think the idea you mentioned to connecting minivans metal frame bumpers will work.

But again use feasible things. Don't know what your project exactly, but is sounds awesome. 😀

I don't have more knowledge about it! This idea strike in my mind as soon as i read this thread.
But i think it will work.
In actual railway shock absorber, there is a oil reservoir. When collision occur the oil moves to another reservoir. Due to this oil transfer the pressure is increases in controlled volume(cylinder). So more energy is required to transfer more oil.Hence energy is absorbed. This gradually decreases the impact.
You may do this by using old motorcycle shock absorber. Or design your own !!!
I recommended two shock absorber at both side, you can also use small capacity absorber at back side!!

Why cant v use a different material for the car's body like fiber may b not pure fiber but that must observe little shock and gets reflected from the collision with small damage in the vehicle. Is it possible????

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You can add fiber material at front side You cant make hole chassis of fiber material.It can't give required strength.
But it gives less energy absorbing.
You may correct me if i am wrong!

@gg_gaurav: Yes I searched about that railway shock absorber, it is a wonderful idea. I want to know more. Good going. Keep posting things. 😁

Well I wasn't going to use Railway Shock Absorbers. They're too huge!!!
What I was considering is using motorcycle shock absorbers. The size is quite feasible and if placed properly, would be very effective, in both low and high impact crashes.
Another thing that came to mind was using tires. Or tyres, what ever suits your fancy. Not full tires mind you but have sections of tires connected to the front (and back) bumbers and have them inflated with air. Would be pretty cheap but I wouldn't know how to calculate their effectiveness.

I've already started drawing it. I'll post the pics once I'm done.

Any ideas how to properly calculate the amount of energy absorbed by a shock absorber? I don't like the way I calculated it so far.

So no one has any more ideas how to help? The shock absorber idea is too weak. The total amount of force my absorbers can withstand is 7000N where as the amount of force generated in a crash is 723380N. Any ideas anyone?

Why regenerative braking? Any braking should do. Combine both ideas adding an external air bag deployment. Every bit helps.

TRIZ 40 is only a pointer to nudge your thoughts. I tried it on this problem. One outlandish solution that I could get was to extend an inclined plane out so that the other vehicle just shoots over your car as shown in film stunts.

Bioramani

The problem is that in a head on collision there is very little displacement available. The front end comes to a stop while the vehicle and contents are still at the velocity prior to impact. We have to handle the inertia issue. Probably an ejector seat and the whole top of the car splitting open may help. We have to remember that the trajectory would be a parabola, which will be a function of the forward velocity and the ejector velocity.

Bioramani

True.... In case of the inertia issue, I was thinking of integrating a pre braking system with an active bumper system using Aluminum foam to absorb the impact energy. Therefore slowing down the car to an acceptable degree before crashing, and minimizing the size of the aluminum foam bumper.

muhaimmeduTrue.... In case of the inertia issue, I was thinking of integrating a pre braking system with an active bumper system using Aluminum foam to absorb the impact energy. Therefore slowing down the car to an acceptable degree before crashing, and minimizing the size of the aluminum foam bumper.

At what gap does the brake kick in? After contact what will be the length by which the foam collapses? What will be the maximum combined collision velocity? Assuming that both drivers may try to evade a head on collision, the angle of impact may not be 180 degrees. This will modify the shock absorption.

A sensitive ultra sound or microwave distance gauge with Doppler (for velocity calculation)and a fast microcontroller with proper software may take early action. Even then, only the vehicle with this device will get controlled. Even assuming this car comes to a complete halt, the other may still come full tilt and ram. Still, the inertial damage in this car may be acceptable.

Bioramani

I was planning on using a sensor system with a microcontroller to help take action mate. As for the distances I just need to crunch the numbers so they're not too large or small, if I mess that up think of the consequences, (*shudder).

Well mate it's completely better than ramming head onto another moving car with your own car's full inertia. Plus the aluminum foam would help dampen up the collision and give the crumple zone some leeway.

A primary assumption is that the collision is directly frontal and not at any angle. It's just to simplify our scenario since we don't have the time to take everything into consideration, not even the various frontal collision types.

Our combined collision velocity is 100kph, also an assumption that our professor gave us so we don't build a system that's too weak and pointless (for lower speeds).

But seriously thanks bioramani, those are awesome points you mentioned. Keep it coming guys! I'll post pics and details once the project is done. isA.