Page 56 - ATZ11 November 2019 Professional

DEVELOPMENT BODY

Dynamic experiment Quasi-static experiment FIGURE 2 Replacement
v = 8.89 m/s; E = 3580 J v = 0.17 mm/s test rig for side impact
kin
beam with quasi-static
Aluminum honeycomb
Aluminum honeycomb at the crash block
and dynamic test
setup (© WoodCar)
Side impact beam
Aluminum honeycomb
Aluminum
on the test frame
Impactor (D = 254 mm)

Energy
100 %
80 %
60 %
40 %
20 %
0 %
Al honeycomb at the crash block
Al honeycomb on the test frame
Side impact beam

Two load cases were selected for combs To identify the proper parameter set,
combs and the bending of steel plates,
benchmarking the wood-based side respectively. In that way the boundary the following method was applied: First,
impact beam: the legislative FMVSS 214s conditions in the installed configuration the three vehicle models (family car A,
and the consumer protection US-NCAP are replicated. family car B and SUV C) were exposed to
pole test. To cut time- and calculation In the development and validation of the US-NCAP pole impact test in a vir-
efforts in the first phase of the project, the replacement test rig two other vehi- tual test environment. The side impact
a side impact beam replacement test rig cles were considered. The three side beams were equipped with five force and
was developed, FIGURE 2. In the test rig, impact beams (extracted from the one torque transducers along the beam axes,
the ends of the side impact beam have OEM model and from the two open- to obtain the forces/torque intrusion
two degrees of freedom, namely the source FE-models), were used to choose curves for each vehicle. Additionally, the
axial translation and the rotation about the following parameters: weight of resulting intrusions were measured rela-
the vertical axis. These degrees of free- impactor, thickness of the bending tively to the total vehicle and absolutely
dom are constrained, through the axial- plates and energy absorption of the to the clamping of the side impact beam.
aluminum honey-
yielding behavior of aluminum honey- combs. In addition, the internal energies (that

Energy absorption
100 %
80 %
60 %
40 %
Reference steel side impact beam Wood-based side impact beam
20 %
1.18 kg 1.00 kg
0 %
Baseline steel Wood-based demonstrator
Al honeycomb at the crash block
Al honeycomb on the test frame
Side impact beam
Force intrusion
T = 28 ms 30 T = 28 ms
Force [kN] 20
10
0
0 50 100 150 200 250 300
Instrusion [mm]
Wood-based demonstrator
FIGURE 3 Energy absorption and force intrusion Baseline steel
of the side impact beam: comparison of the orig- Initial crush resistance 150 mm (FMVSS214s)
inal to the wood-based concept (© WoodCar) Intermediate crush resistance 300 mm (FMVSS214s)
50