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>.