Evaluation of finite element models of the advanced Pedestrian Legform Impactor
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
According to the National Highway Traffic Safety Administration (NHTSA), 54,769
pedestrians were injured in the United States during 2020 (Stewart, 2023). Among
these injured pedestrians, 12,623 experienced incapacitating injuries (National Center for Statistics and Analysis, 2022). To minimize such injuries, both physical and
Finite Element (FE) representations of the advanced Pedestrian Legform Impactor
(aPLI) are used in vehicle design to reduce the risk of serious injuries to the lower
extremities. The physical aPLI is a mechanical representation of the human leg
used to assess knee, tibia, and femur injury risk in crash testing. This project aimed
to evaluate the performance of two different FE models of aPLIs in LS-DYNA by
conducting dynamic validation tests. In addition, this project aimed to determine
which FE aPLI model better correlated with physical test results using a Generic
Vehicle Test Rig (GVTR) within the limitations set by this thesis.
A dynamic validation test was conducted on a physical aPLI to ensure its validity.
The test employed an energy absorber attached to a linearly guided sled, which im pacted the aPLI at 40 km/h. The resulting signal responses from sensors in the knee,
tibia, and femur had to fall within a specified certification corridor for the physical
aPLI to be considered valid. This test was then mimicked in the FE environment,
and the performance of the FE aPLI models was evaluated based on how close to
the physical test results they predicted. The two FE aPLI models were Humanetics
v1.2.6 and ATD-models D02.11. A sensitivity study was conducted during this step
of the project, in which the FE dynamic validation test was performed using the
maximum and minimum tolerance limits to investigate if the signal responses from
the FE aPLI models would diverge. The next step consisted of simulating impact
tests with the GVTR and comparing the results to physical test results.
The results showed that the Humanetics FE aPLI model demonstrated better and
more consistent performance in the validation test. It was slightly more robust in
the FE sensitivity study and produced results that correlated more closely with
physical impact tests with the GVTR.
Beskrivning
Ämne/nyckelord
aPLI, FE, GVTR, Pedestrian, Leg impactor