Post on 16-Apr-2017
Solar Sports Car - Impact Attenuators
Mitchell FrickAdam RichardsRyan Kaye-SimmonsJackson Wall
● Inspired by post-apocalyptic films
● Designed to be driven all day on purely solar energy.
● not massed produced
The Immortus
● foundation for new technologies
What is an impact attenuator?
Absorbs kinetic energy in the event of a collision.
Distributes force evenly across the impact members.
Reduces the magnitude of deceleration felt by the passengers.
● Commonly known as a crumple zone.
● Preserve and protect life of passengers inside.
http://tristanmac.tripod.com/id20.html
What does an impact attenuator need to do?
When travelling under 15 km/h, the main goal is to minimize repair costs of the car.
At speeds between 15 and 40 km/h, the first aim is to protect pedestrians from injury.
At speeds over 40 km/h, damage to the car and injury to pedestrians is unavoidable so the most important concern is to guarantee occupant protection.
LimitationsExtra weight will reduce the efficiency of the electric vehicle.
High cost of repair resulting from crash.
Car companies release very little crash testing data.
The immortus has a limited budget.
Design ideas - Absorbing members
https://www.google.com/patents/US6312028
Front impact energy absorbing member
● Typical designs for the modern car involve a hollow tube or honeycomb structure internally.
● Two supporting members that are perpendicular to the direction of collision.
● Connected to safety cell.
Different design ideasExplosives:
Very small explosive charges are fixed to box-shaped beams in the front of the chassis.
● Sensors are used to detect a certain crumpling deformation distance in the beams.
https://i.ytimg.com/vi/0xVEC5GqMyk/maxresdefault.jpg
Formula SAE attenuator
SAE team currently using a SAE standard foam nose cone.
Previously, aluminium honeycomb was used.
Expensive testing.
This is design is specific to Formula SAE since higher velocity collisions can be expected, as well only having one passenger to worry about.
http://www.motoiq.com/MagazineArticles/ID/2165/PageID/3749/Formula-SAE-Part-2-The-Little-Team-That-Could.aspx
TestingMost car companies do not
publicly reveal crash testing results.
Performing tests means destroying the attenuator.
Expensive and time consuming.
https://www.youtube.com/watch?v=-TEYm1hxDL0
MaterialsFoam
Advantages:- Lightweight- Withstanding of low speed
collisions- Easy to manufacture polymers of
varying density
http://www.formula-seven.com/products/impact-attenuator-type-12/
MaterialsAluminium
Foam or Honeycomb http://waterocket.explorer.free.fr/images/Aluminium_honeycomb_2.jpg
Advantages:- Lightweight.- Control direction of deformation
and force distribution.- Can withstand low speed
collision.
http://www.siws.fr/2013/08/20/30455/
Position on car/mounting
Crumple zones should be placed in rear, side and front areas.
Upright motor mounts allow for more space available in the front of the car.
Protect “safety cell” of car where occupants are.
http://www.hk-phy.org/contextual/mechanics/mom/impul04_e.html
Where we are at
Still deciding on material
Researching design ideas
And bargaining for space
ReferencesEVX Ventures, viewed 18 March 2016, <http://www.evxventures.com>.
Version 2013, Application - Car Body - Crash Management Systems, European Aluminium Association, viewed 19 March 2016, <http://european-aluminium.eu/wp-content/uploads/2011/12/4_AAM_Crash-management-systems1.pdf>.
Johnny K Larsson & Clas Jenstrom, June 25 2002, ‘Front Structure in a Vehicle’, Patent no. US6409253, viewed 17 March 2016, <https://www.google.com/patents/US6409253>.