Part Description:
The part covers two batteries behind a truck cabin. The driver needs to
stand on the battery cover for maintenance, occasionally with one foot
only.
Requirements:
Under load the part is allowed to displace until a certain point. It
must not touch the batteries or its electrodes and has to withstand a
load of approx. 150 kg without any damage.
Current Part:
Material SMC (UPGF30), Weight 3.8 kg, Thickness 3 mm
The current part fulfils the requirement in terms of displacement.
Although, under max. load it starts to crack within the front-area.
Request to QPC:
Comparison of different
materials with current geometry by FEA
Recommendation for a redesigned
GMT solution to achieve less weight and increased strength. The deflection must not be higher than for the current part.
In addition a steel frame insert
as possible reinforcing element has to be studied.
Results of material study (FEA):
With a combination of GMT and GMTexTM, weight would decrease approx.
30%. Even with a deflection increase of more than 30% versus SMC, the
material would withstand max. stress with a safety margin of approx.
29%. According to stiffness and weight, a steel frame insert shows no
advantages.
Suggested GMT Solution:
Material GMT (B100F30) + GMTexTM (4/1-90° Middlelayer), weight max. 2.2
kg, Thickness 3 mm.
The part fulfils all requirements. By redesign of the geometry and a
certain combination of material it becomes stiffer and gets a safety
margin of 33% at same deflection as the SMC solution.
