In a Fraction of a Second

To ensure that the safety of all road users doesn’t depend on computer simulations alone, crash tests are carried out with real cars every day in Sindelfingen, Germany.

The age of modern, groundbreaking safety testing at Daimler was ushered in with the first crash test on September 10, 1959. Since then, increasingly sophisticated crash tests have generated more and more meaningful results, as the company pursues its aim of offering road users increasingly better protection. Painstakingly prepared crash tests and advanced crash dummies are among the standard tools used nowadays to develop passive safety systems. After all, almost four million people are on the road every minute all over the world. The number of passenger vehicles in the world will double over the next 20 years, and around two billion passenger vehicles will be registered 40 years from now. Given the ongoing increase in traffic volumes, it’s perhaps not surprising that more than 10,000 crash tests have been performed in the crash hall in Sindelfingen since it commenced operations in 1975.

The facility, which was thoroughly modernized in 1998, tests individual configurations and different engine and transmission variants at various stages of a vehicle’s development. The engineers investigate a diverse range of accident situations, including frontal collisions against a rigid wall at 56 kilometers per hour and offset crashes at 64 kilometers per hour. In the latter, a part of a vehicle’s front collides against an obstacle. Tests are also conducted to find out how a vehicle behaves when it collides against a pole or is hit in the side or the rear. Other tests determine the quality of child and pedestrian safety. The test program includes 30 impact configurations that are currently required for the worldwide registration of a new car. In addition, Mercedes-Benz conducts many other highly demanding crash tests to ensure safety in its passenger vehicles. These include the rollover and roof-drop tests plus special frontal, side, and rear crash tests. The aim of all of these tests is to align the vehicle’s safety concept with real-life traffic and accident conditions, and thus provide road users with optimum protection.

To achieve this goal, the crash hall is equipped with an acceleration track that can extend up to 92 meters in length. The vehicles are accelerated along the first half of the track by a cable pulley system. Here, the fine tuning that is required to achieve exactly the desired speed is carried out along the second half of the track. Once this speed has been reached, the system detaches itself from the vehicle, which then, together with its artificial occupants, crashes into a deformable barrier, for example, or flips over on a ramp. The actual crash lasts for only about 100 to 150 milliseconds. During this fraction of a second, up to 200 sensors register every reaction involving the vehicle and the dummies. Each of these sensors has its own ID system so that the data generated during a test can subsequently be precisely assigned. The crash is also recorded by state-of-the-art video technology at a rate of 1,000 images per second so that the test can be visually evaluated at normal speed and in extreme slow motion. In addition, precise measurements are taken of the materials that penetrate the vehicle (intrusions) and of any corresponding deformations. The engineers also determine exactly how much force is needed to open the car doors.

Photo Gallery

Crash hall in Sindelfingen, Germany

Test vehicle and dummy

Test vehicle and dummy

Cable pulley system in the hall floor

Test vehicle

Immovable steel wall

After the crash

After the crash

Paint mark on the obstacle

Crash test dummy

Crash test dummy

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Crash tests are the visually spectacular part of Daimler’s safety philosophy. However, ensuring safety is a holistic task that goes far beyond merely meeting crash test standards. The Daimler engineers therefore show comparable dedication when it comes to developing the experimental safety vehicle ESF 2009, for example, or to conducting accident research. Because Daimler’s safety concept is based on a real-life safety philosophy and actual accidents, the company’s experts each year analyze between 130 and 170 accidents in which Daimler cars or commercial vehicles were involved. Besides researching the way the vehicle has been deformed, the experts examine the accident locations and any injuries the occupants may have received. Using photos, sketches, and accident reports, the experts can also create computer simulations that allow them to make inferences regarding how an accident happened.

The tests in the Sindelfingen crash hall are augmented by computer simulations. Although these simulations will probably never replace real-life tests, they expand the range of possibilities for understanding the interplay between diverse components and systems. In addition, they help the researchers use this knowledge to implement new measures. To create these simulations, the engineers make thousands of crash calculations during each stage of a vehicle’s development. Each vehicle is involved in around 5,000 virtual accidents before it has to undergo its final real-life safety testing in the crash hall. All this is necessary if the vehicle is to fulfill the general legal approval requirements and Daimler’s substantially higher safety standards.

Text: Andreas Kunkel

Photography: Stefan Hohloch

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