Thermoplastic Roof Crush Countermeasure Design for Improved Roof Crush Resistant to Meet FMVSS-216 2011-01-1119
An automobile is designed to meet numerous impact events,
including frontal impact, side impact, rear impact, and roll over.
Roof crush resistance is a test defined by Federal Motor Vehicle
Safety Standard (FMVSS) 216. The intent of this test is to evaluate
the strength of the roof and supporting body structure during a
vehicle rollover. Steel countermeasures are typically used as
structural-reinforcing elements to the body structure to improve
the crush strength of a vehicle roof.
This paper presents a thermoplastic countermeasure (CM) design
as a light-weight solution to replace traditional steel
countermeasures. Two concepts are discussed in the paper: an
all-plastic countermeasure and a plastic/metal hybrid
countermeasure consisting of stamped steel with a thermoplastic
reinforcing rib structure. Finite Element (FE) methods using
LS-DYNA are used to evaluate the performance of these
countermeasure concepts. A generic Finite Element model of a sport
utility vehicle is used in the analysis. The countermeasure
concepts are assembled inside the B-Pillar and the crush strength
of the roof is evaluated as per FMVSS-216. This study shows that
the thermoplastic countermeasure can be developed with similar
stiffness and strength as steel countermeasure, yet with ~40-50%
mass savings. This paper provides an overview of the performance
for the thermoplastic countermeasures.