0
TECHNICAL PAPERS: Joint/Whole Body

Head Kinematics in Mini-Sled Tests of Foam Padding: Relevance of Linear Responses From Free Motion Headform (FMH) Testing to Head Angular Responses

[+] Author and Article Information
J. Ivarsson

UVa Center for Applied Biomechanics, 1011 Linden Avenue, Charlottesville, VA 22902

D. C. Viano

Crash Safety Division, Department of Machine and Vehicle Systems, Chalmers University of Technology, SE-412 96 Göteborg, SwedenGeneral Motors Research and Development Center, Warren, MI 48090-9055Saab Automobile AB, SE-461 80 Trollhättan, Sweden

P. Lövsund

Crash Safety Division, Department of Machine and Vehicle Systems, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

Y. Parnaik

Bioengineering Center, Wayne State University, Detroit, MI 48202

J Biomech Eng 125(4), 523-532 (Aug 01, 2003) (10 pages) doi:10.1115/1.1590360 History: Received February 12, 2002; Revised April 01, 2003; Online August 01, 2003
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.

References

Sounik, D. F., Gansen, P., Clemons, J. L., and Liddle, J. W., 1997, “Head-Impact Testing of Polyurethane Energy-Absorbing (EA) Foams,” SAE International Congress and Exposition, SAE Technical Paper No. 970160.
Myers, B. S., and Nightingale, R. W., 1997, “The Dynamics of Head and Neck Impact and its Role in Injury Prevention and the Complex Clinical Presentation of Cervical Spine Injury,” in Proceedings of the 1997 International IRCOBI Conference on the Biomechanics of Impact, pp. 15–33.
Nightingale, R. W., McElhaney, J. H., Camacho, D. L., Kleinberger, M., Winkelstein, B. A., and Myers, B. S., 1997, “The Dynamic Responses of the Cervical Spine: Buckling, End Conditions, and Tolerance in Compressive Impacts,” in Proceedings of the 41st Stapp Car Crash Conference, SAE Technical Paper No. 973344, pp. 451–471.
Camacho,  D. L. A., Nightingale,  R. W., and Myers,  B. S., 2001, “The Influence of Surface Padding Properties on Head and Neck Injury Risk,” ASME J. Biomech. Eng., 123(5), pp. 432–439.
Nagy,  A., Ko,  W. L., and Lindholm,  U. S., 1974, “Mechanical Behavior of Foamed Materials Under Dynamic Compression,” J. Cell Plast., 10, pp. 127–134.
Monk, M. W., and Sullivan, L. K., 1986, “Energy Absorption Material Selection Methodology for Head/A-pillar,” in Proceedings of the 30th Stapp Car Crash Conference, SAE Technical Paper No. 861887, pp. 185–198.
Rossio, R. C., Vecchio, M., and Abramczyk, J., 1993, “Polyurethane Energy Absorbing Foams for Automotive Applications,” SAE International Congress and Exposition, SAE Technical Paper No. 930433.
Sounik, D. F., McCullough, D. W., Clemons, J. L., and Liddle, J. L., 1994, “Dynamic Impact Testing of Polyurethane Energy Absorbing (EA) Foams,” SAE International Congress and Exposition, SAE Technical Paper No. 940879.
Chou, C. C., Zhao, Y., Lim, G. G., Patel, R. N., Shahab, S. A., and Patel, P. J., 1995, “Comparative Analysis of Different Energy Absorbing Materials for Interior Head Impact,” SAE International Congress and Exposition, SAE Technical Paper No. 950332.
Faruque, O., Liu, N., and Chou, C. C., 1997, “Strain Rate Dependent Foam-Constitutive Modeling and Applications,” SAE International Congress and Exposition, SAE Technical Paper No. 971076.
Ullrich, J., Emanuel, D., Fong, W., Nusholtz, G., Chaudhry, M., and Williams, S., 1997, “Comparison of Energy Management Materials for Head Impact Protection,” SAE International Congress and Exposition, SAE Technical Paper No. 970159.
Yu, L. C., Kowalski, E. L., and Elchison, B. K., 1997, “Material Comparison using Free Motion Headform (FMH) Impact and Alternative Test Method,” SAE International Congress and Exposition, SAE Technical Paper No. 970165.
Holbourn,  A. H. S., 1943, “Mechanics of Head Injuries,” Lancet, 2, pp. 438–441.
Hodgson, V. R., and Thomas, L. M., 1979, “Acceleration Induced Shear Strains in a Monkey Brain Hemisection,” in Proceedings of the 23rd Stapp Car Crash Conference, SAE Technical Paper No. 791023, pp. 589–611.
Löwenhielm,  P., 1975, “Mathematical Simulation of Gliding Contusions,” J. Biomech., 8(6), pp. 351–356.
Margulies,  S. S., and Thibault,  L. E., 1989, “An Analytical Model of Traumatic Diffuse Brain Injury,” ASME J. Biomech. Eng., 111(3), pp. 241–249.
Viano, D. C., Melvin, J. W., McCleary, J. D., Madeira, R. G., Shee, T. R., and Horsch, J. D., 1986, “Measurement of Head Dynamics and Facial Contact Forces in the Hybrid III dummy,” in Proceedings of the 30th Stapp Car Crash Conference, SAE Technical Paper No. 861891, pp. 269–289.
Shea,  R. T., and Viano,  D. C., 1994, “Computing Body Segment Trajectories in the Hybrid III Dummy using Linear Accelerometer Data,” ASME J. Biomech. Eng., 116(1), pp. 37–43.
Amori, R. T., Armitage, R. R., Chou, C. C., Lim, G. G., Patel, R. N., and Shahab, S. A., 1995, “Influence of System Variables on Interior Head Impact Testing,” SAE International Congress and Exposition, SAE Technical Paper No. 950882.

Figures

Grahic Jump Location
Dynamic stress-strain characteristics for seven of the nine foam types used in the mini-sled tests
Grahic Jump Location
(a) The mini-sled in its starting position with the pneumatically controlled accelerating piston contacting a bracket at the rear of the sled. Note the support bar preventing the dummy head from moving rearwards during sled acceleration, which here has been put into supporting position. The support bar rotates downward during sled transit and is not a factor in the subsequent head impact. (b) The mini-sled in a position just prior to the dummy head contacts the foam. A layer of tape to reduce the friction between the head and foam during impact covers the face and forehead. A sample of EPS is mounted on the aluminum plate. Below the foam sample is a piece of honeycomb to decelerate the sled. Note that the support bar for the head is in its nonsupporting position.
Grahic Jump Location
Midsagittal plane positioning of accelerometers inside the dummy head. The biaxial array accelerometers denoted CG-x and CG-z were also used to measure linear x and z acceleration at the head CG. The coordinate system, which is attached to the head CG, follows the Hybrid III sign convention, i.e., the x axis coincides with the posteroanterior direction (anterior direction positive) and the z axis coincides with the superoinferior direction (inferior direction positive).
Grahic Jump Location
Illustration of head kinematics during the first 35 ms following initial head-foam contact at t=0. The frames are taken from the video sequence of test 49, a 7.03 m/s impact into FPU of 64.0 kg/m3.
Grahic Jump Location
Responses as measured in the test shown in Fig. 4. (a) x,z, and resultant linear acceleration at the head CG and sled deceleration. (b) Sagittal plane angular acceleration as calculated from the in-line system and biaxial array, neck force Fx acting on the head in the x direction and neck moment My acting on the head about an axis parallel to the y axis through the head CG. The noise in the acceleration time history from the in-line system occurring between t=22 ms and t=26.5 ms is due to the support rod hitting the back cap of the dummy head, thus causing a slight ringing in the in-line accelerometers. (c) Sagittal plane angular velocity calculated by integration of the acceleration time histories shown in (b).
Grahic Jump Location
Peak values of angular acceleration and change in angular velocity as functions of peak values of resultant linear acceleration and HIC36 as measured in all the mini-sled tests.
Grahic Jump Location
HIC36 as a function of peak resultant linear acceleration for the low-, intermediate-, and high-speed tests. Nonlinear regression functions, in which HIC36 was a function of peak resultant linear acceleration raised to the power of 5/2, have been fitted to the results from the low- (r=0.981), intermediate- (r=0.949), and high-speed (r=0.694) tests. The use of linear regression would have resulted in slightly lower correlation for the low- (r=0.970) and intermediate-speed (r=0.944) tests and slightly higher correlation for the high-speed tests (r=0.720).
Grahic Jump Location
Head-foam contact force in the direction of sled motion (as recorded by the load cells backing up the inclined aluminum plate) and linear x acceleration of the dummy head (as recorded by the CG-x accelerometer in the biaxial array) for two high-speed tests in which the foam did not bottom out (test 59, a 9.87 m/s impact into EPP of 48.0 kg/m3) and bottomed out (test 54, a 9.69 m/s impact into EPP of 20.8 kg/m3).
Grahic Jump Location
Peak responses in the high-speed tests in which the foam samples did not bottom out (solid circles) and bottomed out (open circles). (a) Peak angular acceleration as a function of peak resultant linear acceleration. (b) Peak angular acceleration as a function of HIC36. (c) Peak resultant linear acceleration as a function of HIC36.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In