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Crash Test

A Crash Test is a form of destructive testing. It is usually performed in order to insure safe design standards.

A crashworthy design reduces death and injury risk. Structure and restraints (safety belts and airbags) are the main aspects of a vehicle’s design. This determines its crashworthiness. Good structure means a strong occupant compartment.  Also there should be crumple zones to absorb the force of a serious crash.  Side structures manage the force of a striking vehicle . A strong roof ensures it does not collapse in a rollover.

Structure/Safety Cage:
Vehicle’s structural performance engineers measure the amount of intrusion into the occupant compartment after the crash. In the moderate overlap test, measurements are taken at nine places around the driver’s seat. In the small overlap test, 16 locations on the driver side interior and exterior are measured. The amount and pattern of intrusion shows how well the front-end crush zone managed the crash energy and how well the safety cage held up.

Injury Measures:

 Sensors in the head, neck, chest, legs and feet of the dummy indicate the level of stress and strain on that part of the body.

Restraints/Dummy movement:
Even if injury measures are low, it’s important to consider the dummy’s movement during the crash,  This is because not all drivers are the same size as the dummy or seated exactly the same way. A close call for the dummy could be an actual injury for a person.
Before each crash test, technicians put greasepaint on the dummy’s head, knees and lower legs. After the test, the paint shows what parts of the vehicle came into contact with those parts of the dummy. The paint, combined with high-speed film footage of the crash, allows engineers to evaluate the dummy’s movement.

There are various types of tests:

Frontal impact tests which is what most people initially think of when asked about a crash test. These are usually impacts upon a solid concrete wall at a specified speed, but can also be vehicle-vehicle test. SUVs have been singled out in these tests for a while, due to the high ride-height that they often have.

Offset Tests:

in which only part of the front of the car impacts with a barrier (vehicle). These are important, as impact forces (approximately) remain the same as with a frontal impact test, but a smaller fraction of the car is required to absorb all of the force. These tests are often realized by cars turning into oncoming traffic. This type of testing is done by the USA Insurance for Highway Safety (IIHS), Euro NCAP Australasian New Car Assessment Program and ASEAN NCAP.

Small overlap tests:

This is where only a small portion of the car’s structure strikes an object such as a pole or a tree.  This is the most demanding test as it loads the most force onto the car’s structure at any given speed. These are usually conducted at 15-20% of the front vehicle structure.

Side Impact Tests:

These forms of accidents have a very significant likelihood of fatality, as cars do not have a significant crumple zone to absorb the impact forces before an occupant is injured.

Roll Over Tests:

These test a car’s ability (specifically the pillars holding the roof) to support itself in a dynamic impact. More recently dynamic rollover test have been proposed as opposed to static crush testing.

Roadside hardware crash tests are used to ensure crash barriers and crash cushions will protect vehicle occupants from roadside hazards, and also to ensure that guardrails, signposts, light poles and similar appurtenances do not pose an undue hazard to vehicle occupants.

Old versus New:

Often on old and big car against a small and new car or two different generations of the same car model. These tests are performed to show the advancements in crashworthiness.

Computer Model:

Because of the cost of full side crash tests, engineers often run many simulated crash tests using computer models to refine new vehicle or barrier designs before conducting live tests.

Crash tests are conducted under rigorous scientific and safety regulations. Each crash test is very expensive so the maximum amount of data must be extracted from each test. Usually this requires the use of high speed data acquisition, at least one triaxial accelerometer and a crash test dummy.
There are a number of crash test programs around the world dedicated to providing consumers with a source of comparative information in relation to the safety performance of new and used vehicles.

The Insurance Institute for Highway Safety, as at October 2, 2014, published safety results for three large luxury cars in the IIHS small overlap front test.  The Infiniti Q70 achieved a good rating, the Lincoln MKS earned a poor rating and the BMW 5 series earned a marginal rating.

On September 18, 2014, the 2015 Volkswagen Jetta earned the IIHS Top Safety Pick award, thanks to a structural upgrade to improve small overlap protection.

The Kia Soul, previously rated poor in the IIHS small overlap front test now earns a good rating, due to structural improvements. The Kia Forte also improved, but only to a marginal rating.