Crashworthiness
Dynamic Component Test
- Dynamic 3-point bending tests are performed on an improved setup of Drop Weight Tower with two high speed cameras (assisted by DIC analysis), application of strain gauges on the component and high-speed thermography.
- Uniaxial compression tests of crash boxes can be performed with the recording of deformation by means of Digital Image Correlation in 3D mode with two cameras. The deformation fields are measured around wrinkles and potential cracks. The samples can be equipped with the strain gauges. Results are provided as force-displacement curve, max. force or crash energy at certain displacement level.
Intrinsic material crashworthiness
Fracture and crash ductility assessment. Quasi-static bendability and fracture toughness tests. V-bending tests according to VDA 238-100 are state of the art to evaluate the crash ductility of metal sheets. The evaluated bending angle is a measure of the material’s ability to be bent in a tight radius, which is related to the damage initiation resistance in a crash test.
On the other hand, fracture toughness is the key parameter to describe the overall crash fracture behaviour of high-performance sheet material once the damage is initiated. The essential work of fracture (EWF) is a suitable parameter to assess the energy dissipated during the ductile crack propagation process, which has a strong influence on crash energy absorption.
V-bending tests
Quasi-static V-bending tests are performed according to VDA 238-100. V-bending tests consist of bending a piece of sheet metal using a sharp punch tip radius (0.2-0.4 mm) and minimal spacing between support rollers.
The load and the punch displacement are recorded, and the bend angle is determined analytically.
The characteristic parameter is the bending angle at maximum force, which provides a measure of the sheet metal bendability. The deformation mode is plane strain tension, which is similar to the observed in crash folding.
