Researchers at UMass Dartmouth developed a novel helmet padding called Fibrous Energy Absorbing Material (FEAM) to reduce traumatic brain injuries. They used finite element modeling to simulate FEAM configurations under different impact conditions. A custom testing apparatus called a Guided Weight Drop Tester was also designed and built to physically test FEAM samples. The modeling provided preliminary results on impact energy absorption and acceleration/deceleration of a drop weight for various FEAM densities and fiber weights at projectile velocities of 3 m/s and 5 m/s. Physical testing with the new apparatus will allow further evaluation of FEAM to help develop safer helmets.

1. UMass Dartmouth • College of Engineering • umassd.edu/engineering
Abstract
Objectives
Methods
GWDT Development Results
Conclusions References Acknowledgements
From contact sports such as football and hockey to military
and police combat, the need for effective energy absorbing
materials is strong. There is increased interest in reducing
traumatic brain injuries (TBIs) by developing padding
materials that can reduce normal and rotational impact
forces. In order to respond to this need, researchers at the
University of Massachusetts Dartmouth have developed a
novel helmet padding material known as Fibrous Energy
Absorbing Material (FEAM). Its 100% textile configuration
allows it several advantages over other padding materials.
It is machine washable, breathable, and modular with other
padding designs. In this project, the preliminary
development of finite element simulations to model various
FEAM configurations is discussed. Results are presented
for projectile velocities of 3 m/s and 5 m/s. In addition, the
design of a custom testing apparatus for physical samples
is reviewed.
ANSYS® Workbench 16.2 was used for developing
various finite element models for a parametric study on:
• Impact energy absorption
• Acceleration and deceleration of a drop weight
A Guided Weight Drop Tester (GWDT) was produced
from the ground up. It is fitted with PCB Piezotronics®
sensors and NI Sound and Vibration Analysis® software.
Summary of Impact Simulations…
The UMD research team Corsair Innovations is now
prepared to conduct high-energy impact testing thanks
to the new GWDT machine. This brings us closer to
securing first place in the Head Health Challenge,
which would result in a $500K prize to support our
research.
Further development of FEAM models should be
conducted considering the proper Prony shear
relaxation data for the material. This preliminary study
has shed some light on the challenges of developing
accurate computer models of this complex material.
• Liu, Y., Hu, H., Long, H., & Zhao, L. (2012). Impact
compressive behavior of warp-knitted spacer fabrics
for protective applications. Textile Research Journal
, 82 (773), 774-788.
• Matos, H. D. (2014). Energy Absorption of Flocked
Materials during Impact. University of
Massachusetts, Dartmouth, Mechanical Engineering.
North Dartmouth: College of Engineering.
• Metz, R. (2007). Impact and Drop Testing with ICP
Force Sensors. PCB Piezotronics, Inc., Depew, NY.
• To design, construct, and calibrate a custom high
energy impact tester for use in the third Head Health
Challenge and other future projects
• To research and develop a preliminary approach for
modeling FEAM behavior under impact
I would like to sincerely thank the following individuals:
Dr. Vijay Chalivendra for providing support throughout
the project as my advisor
Mr. Helio Matos whose Master’s thesis was very
informative in my research
Mr. Karoly Fodor for assisting me with the GWD system
upgrade and calibration tests
1Department of Mechanical Engineering, 2Department of Bioengineering
Diarny O Fernandes1, Vijaya B Chalivendra1, Yong K Kim2, Armand Lewis2
Finite Element Modeling and Testing of Energy Absorbing Materials for
Protective Headgear
UMD TEAM IS 1 OF 5 FINALISTS,
WINNING $250K TO SUPPORT R&D
Early Concepts (Fall 2015)
Finite Element Modeling Results
Model 1. Velocity: 3 m/s
Denier: 60
Area Density: 70 fib/mm2
Final Product (Spring 2016)
Raw Impact Event Data… Filtered Data (Low-Pass)…
Actual FEAM… Computational Model… Analysis Parameters…
• One fiber length: 1mm
• Two fiber weights: 60 and 45
denier
• Two velocities: 3 m/s and 5
m/s
• Two area densities: 50
fibers/mm2 and 70 fibers/mm2
Model 2. Velocity: 3 m/s
Denier: 60
Area Density: 50 fib/mm2
Model 3. Velocity: 3 m/s
Denier: 45
Area Density: 70 fib/mm2
Model 4. Velocity: 3 m/s
Denier: 45
Area Density: 50 fib/mm2
Model 5. Velocity: 5 m/s
Denier: 60
Area Density: 70 fib/mm2
Model 6. Velocity: 5 m/s
Denier: 60
Area Density: 50 fib/mm2
Model 7. Velocity: 5 m/s
Denier: 45
Area Density: 70 fib/mm2
Model 8. Velocity: 5 m/s
Denier: 45
Area Density: 50 fib/mm2
Impact Plate Acceleration (g) 
Drop Weight Acceleration (g) 
Impact Force (kN) 
Trimmed Data…