Team-BHP > Road Safety


Reply
 
Thread Tools Search this Thread
Old 29th January 2020, 14:13   #31
Senior - BHPian
 
clevermax's Avatar
 
Join Date: Jun 2006
Location: Tvm/Amsterdam
Posts: 1,748
Thanked: 830 Times
Default Re: Safety in real life

Quote:
Originally Posted by Jeroen View Post
If two identical cars crash head on, both doing identical speed, it is the same as one car crashing into a immovable object such a wall.
Bit confused here - did you mean two cars crashing head on at say 30kmph each is equivalent to one of them crashing onto an immovable object at 30kmph?
clevermax is offline  
Old 29th January 2020, 14:18   #32
BHPian
 
black_rider's Avatar
 
Join Date: Jan 2011
Location: Bangalore
Posts: 323
Thanked: 273 Times
Default Re: Safety in real life

Quote:
Originally Posted by vennarbank View Post
The tests are done at 64kmph. But in reality when two car moves and crashes head on at say 60kmph the impact is supposed to be twice than what it was tested.
Not at all. Jeroen's post, quoted below, states the fact, based on which NCAP tests are carried out.
If you want to understand it with practical experiments, you may watch Mythbusters episode "Mythssion control".
https://en.wikipedia.org/wiki/MythBu...ion_Control%22

Quote:
Originally Posted by Jeroen View Post
If two identical cars crash head on, both doing identical speed, it is the same as one car crashing into a immovable object such a wall.
black_rider is offline   (1) Thanks
Old 29th January 2020, 14:25   #33
Distinguished - BHPian
 
Join Date: Oct 2012
Location: Delhi
Posts: 5,218
Thanked: 18,583 Times
Default Re: Safety in real life

Quote:
Originally Posted by clevermax View Post
Bit confused here - did you mean two cars crashing head on at say 30kmph each is equivalent to one of them crashing onto an immovable object at 30kmph?

Yes,


In practice two identical cars hitting one another at identical speed will be somewhat different from one of those cars hitting a wall at that speed.

More to do with how they hit exactly etc.


But in theorie they are identical as the Mythbuster illustrate in a very simple way.
I seem to recall we have a thread around this phenomena?

Jeroen
Jeroen is online now   (2) Thanks
Old 29th January 2020, 15:11   #34
BHPian
 
Join Date: Sep 2005
Location: Chennai
Posts: 134
Thanked: 78 Times
Default Re: Safety in real life

Quote:
Originally Posted by Jeroen View Post
If two identical cars crash head on, both doing identical speed, it is the same as one car crashing into a immovable object such a wall.

Jeroen
Thanks for clarification. In continuation of this, let us assume that car A is at 30kmph and other car B is at 80kmph. Will this still be applicable?
vennarbank is offline  
Old 29th January 2020, 15:45   #35
Distinguished - BHPian
 
Join Date: Oct 2012
Location: Delhi
Posts: 5,218
Thanked: 18,583 Times
Default Re: Safety in real life

Quote:
Originally Posted by vennarbank View Post
Thanks for clarification. In continuation of this, let us assume that car A is at 30kmph and other car B is at 80kmph. Will this still be applicable?
No, the cars need to be identical in weight and speed. That determines their kinetic energy.

In your example the faster case has a considerable higher kinetic energy, especially as in the kinetic formula speed is squared. So once they hit the faster car will actually push the slower car back, so from 30 kmph going one way to going reverse. Huge forces involved!

Safety in cars is down to two main elements: Making sure the occupants don’t get crushed and making sure the occupants have as little deceleration as possible. It is all about how to absorb that energy in a very short space of time and space.


Jeroen
Jeroen is online now   (2) Thanks
Old 29th January 2020, 17:02   #36
BHPian
 
Join Date: Sep 2005
Location: Chennai
Posts: 134
Thanked: 78 Times
Default Re: Safety in real life

Quote:
Originally Posted by Jeroen View Post
No, the cars need to be identical in weight and speed. That determines their kinetic energy.

In your example the faster case has a considerable higher kinetic energy, especially as in the kinetic formula speed is squared. So once they hit the faster car will actually push the slower car back, so from 30 kmph going one way to going reverse. Huge forces involved!

Safety in cars is down to two main elements: Making sure the occupants don’t get crushed and making sure the occupants have as little deceleration as possible. It is all about how to absorb that energy in a very short space of time and space.

Jeroen
Seems i had lots of misconception about this. Thanks a lot for wonderful and clear explanation.
vennarbank is offline  
Old 20th May 2020, 14:29   #37
BHPian
 
Venkatesh's Avatar
 
Join Date: Feb 2020
Location: Hyderabad
Posts: 464
Thanked: 1,111 Times
Default Re: Understanding Euro NCAP safety tests

Euro NCAP has overhauled its testing regime for 2020, with the introduction of new methods to assess crash safety and active safety technology.

Described as “the biggest change to Euro NCAP’s impact testing protocols in a decade” by Thatcham Research director and Euro NCAP board member Matthew Avery, the new regime will be introduced later this year.

The first key change is the adoption of a new “Mobile-offset Progressive Deformable Barrier”, meaning there are now two moving elements to a head-on collision test. Intrusion to both the vehicle and barrier will be measured.

Understanding Euro NCAP safety tests-mpdb_2.png

https://www.autocar.co.uk/car-news/i...y-ratings-2020
Venkatesh is offline   (1) Thanks
Old 20th May 2020, 18:40   #38
Distinguished - BHPian
 
volkman10's Avatar
 
Join Date: Dec 2010
Location: --
Posts: 15,866
Thanked: 35,275 Times
Default Re: Understanding Euro NCAP safety tests

Understanding the 2020 Euro NCAP.


Quote:
A key change is the implementation of a new moving barrier to moving car frontal crash test, replacing the regulation-based moderate offset-deformable barrier test, used by Euro NCAP for the last 23 years. This new crash test not only evaluates the protection of occupants inside the car, but also assesses how the cars’ front-end structurers contribute to injuries in the collision partner. Important innovations are the Mobile Progressive Deformable Barrier and the unique method to rate vehicle compatibility, as well as the first adoption of the world’s most advanced “THOR” mid-sized male crash test dummy.

Side impacts account for the second highest frequency of death or serious injuries. The latest updates to this area of the safety assessment include adjustments to the near-side barrier test speed and mass, increasing the severity of the test. More significantly, Euro NCAP will for the first time evaluate far-side impact protection, focussing on driver protection and the potential interaction between driver and front seat passenger. With the latter test, the protection offered by new-to-market countermeasures such as centre airbags can be adequately verified.



Source:Euro NCAP
volkman10 is offline  
Reply

Most Viewed
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Copyright ©2000 - 2020, Team-BHP.com
Proudly powered by E2E Networks