Citroën Crash Tests - how crash tests are done

introduction
Today, more than ever before, safety sells cars. For car buyers it is a key element of their purchasing decision. It's essential that motoring consumers can obtain reliable and accurate comparative information regarding the safety performance of individual car models. By law, all new car models must pass certain safety tests before they are sold. But legislation provides a minimum statutory standard of safety for new cars, it is the aim of Euro NCAP to encourage manufacturers to exceed these minimum requirements.

This pege contains an explanation of how Euro NCAP's different crash tests are performed and how safety ratings are reached.

front impact
Frontal impact test is based on that developed by European Enhanced Vehicle Safety Committee as basis for legislation, but impact speed has been increased by 8kph (5mph)

Frontal impact takes place at 64 km/h (40 mph), car strikes deformable barrier that is offset.

Readings taken from dummies are used to assess protection given to front occupants:

PROTECTION
	Good
	Adequate
	Marginal
	Weak
	Poor

side impact
Impact takes place at 50 km/h (30 mph). Trolley fitted with a deformable front is towed into the driver's side of the car to simulate a side-on crash.

R point = hip point for 95th percentile male driver. Specialised dummy used in this test to collect maximum information on scale of injury risk present

Readings taken from dummies are used to assess protection given to front occupant:

PROTECTION
	Good
	Adequate
	Marginal
	Weak
	Poor

pedestrian impact
A series of tests are carried out to replicate accidents involving child and adult pedestrians where impacts occur at 40 km/h (25 mph). Impact sites are then assessed and rated fair, weak and poor. As with other tests, these are based on European Enhanced Vehicle Safety Committee guidelines

KEY
	Fair
	Weak
	Poor

head protection or 'pole test'
Accident patterns vary from country to country within Europe, but approximately a quarter of all serious-to-fatal injuries happen in side impact collisions. Many of these injuries occur when one car runs into the side of another. But in Germany over half such injuries occur when a car hits a pole or a tree.

To encourage manufacturers to fit head protection head protection devices, a pole or head protection tests has been added to the Euro NCAP protocols. Side impact airbags help to make this kind of crash survivable. They are also very effective in other types of side impact accidents such as being hit by another vehicle where the bonnet enters the window at head height.

In the new test, the car tested is propelled sideways at 29 km/h (18 mph) into a rigid pole. The pole is relatively narrow, so there is major penetration into the side of the car.

In an impact without the head protecting airbag, a driver's head could hit the pole with sufficient force to cause a fatal head injury.

Typically a head injury criterion of 5000 is possible, five times that which indicates the likelihood of serious brain injury. In contrast, the head injury criterion in these new crash tests with a head protection airbag is around 100 to 300, well below the injury reference value. A side impact airbag with head protection makes this kind of crash survivable despite the severity.

meet the drivers Hybrid III and EuroSID-I have experienced dozens of crashes first-hand. Their role is vital: the accident simulations rely on having a driver and passenger aboard to provide a full picture of likely injuries in a crash, although the pedestrian safety tests use simulated limbs to chart what happens in a collision.

Hybrid III designed to gather data from frontal impacts	EuroSID-1 gathers side-impact data so instrumentation is very different
Hybrid and EuroSID-1 are no ordinary driver and passenger: these are steel-skeletoned, rubber-skinned dummies packed with sensing equipment. To build, they each cost in excess of € 150,000.

what dummies know
Dummies provide vital clues to what happens in a crash. Our limb- by-limb anatomy guide explains how data is sourced.

Head
The head is made of aluminium and covered in rubber 'flesh'. Inside, three accelerometers are set at right angles, each providing data on the forces and accelerations to which the brain would be subjected in a crash.

Neck
Features measuring devices to detect the bending, shearing and tension forces on the neck as the head is thrown forwards and backwards during the impact.

Arms
Carry no instrumentation. In a crash, arms flail and, although serious injuries are uncommon, it is difficult to provide worthwhile protection against them.

Chest (front impact)
Hybrid Ill's steel ribs are fitted with equipment that records deflection of the rib cage in the frontal impact. Injuries result if forces exerted on the chest, such as from the seat belt are too great

Chest (side impact)
The side-impact dummy, EuroSID-1, has a different chest from the others and three ribs are instrumented to record compression of the chest and the velocity of this compression.

Abdomen
EuroSID-I is equipped with sensors to record forces likely to cause abdominal injury.

Pelvis
EuroSID-I has instruments fitted in its pelvic girdle. They record lateral forces that may result in fractures or hip-joint dislocation

Upper leg
In HybricUII, this area is made up of the pelvis, femur (thigh) and knee. Load cells in the femur provide data in frontal impacts on likely injury to all sections, including the hip joint which can suffer fractures and dislocations. A 'knee slider' is used to measure forces transmitted through the dummy's knees, particularly if they strike the lower facia.

Lower leg
Instruments fitted inside the dummies' legs measure bending, shear, compression and tension, allowing injury risks to the tibia (shin-bone) and fibula (connecting knee to ankle) to be assessed.

Feet and ankles
Assessment of injury risk in the frontal impact is made by afterwards measuring distortion and rearward movement of the driver's footwell area.

protocols*

Assessment Protocol and Biomechanics Limits V4.0

Testing Protocols:

EuroNCAP Protocol Changes January 2003

*To view these documents, you will need the latest version of Adobe Acrobat Reader. This can be downloaded from the Adobe web site, free of charge:

.
this page was created 26 january 2003
last change 19 march 2003