29 June 2011: Dedication of the Dynamic Component Testing Facility

12 January 2012

The centrepiece of the dynamic component testing facility at the DLR's Institute of Vehicle Concepts in Stuttgart are two modularly built crash sleds each two metres long and 1.3 metres high. They stand on an 11.5 metre long track railway. 'To be able to test as many different configurations as possible, we decided on a facility with two test sleds', Michael Kriescher explains. That way the impacted test sled can move backwards on impact. 'During one experiment, we accelerate the first test sled, which then collides with a second test sled. A compressed air-driven cylinder propels the first test sled while a hydraulic brake controls the acceleration.' That means the first test sled's acceleration and impact velocity can be exactly defined. With a total mass of 1300 kilogrammes, the test sled's speed can reach a maximum of 64 kilometres per hour. 'This allows us to test large body structures for light to medium duty vehicle concepts under very realistic conditions', says DLR scientist Kriescher.
The second test sled can either be fastened at the back end of the track—for instance to simulate a frontal impact against a stationary obstacle—or be freely movable in the longitudinal direction on the rail, as for instance during a side crash in which an impactor strikes the standing vehicle. Air bag or electronic component tests can also be simulated. 'In that case we use rapid cylinder acceleration for a direct crash impetus on the first test sled', Mr Kriescher reports.


Each of the two test sleds is equipped with a crash-proof data acquisition system that measures and records data from the experiments. 'Depending on equipment, these can be accelerations, strains, forces, or deformations', says Mr. Kriescher. A 19 kW lighting system with eight flood lights is used for high-speed video recordings.
Background for this new facility's construction is that the eco-friendly, or eco-friendlier, car of tomorrow should be first of all lighter while still maintaining safety. For this reason, sustainable, lightweight construction concepts must be developed often using combinations of materials for which no validated calculation methods yet exist. Among these are components or assemblies made of fibre composite materials as well as novel energy absorption concepts. 'With the dynamic test system, we'd like to examine how geometry, joining technology, and material properties play together given entire components, not just individual parts, and what consequences this has for the calculation methodology', summarises Engineer Kriescher. 'In collaboration with colleagues from construction design and calculation, and with scientists from other DLR institutes, we can provide industry with the entire development chain from concept to crash test.'

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