Prediction of impact forces for shock-cushioning elastomer-pad design.
We measure the impact forces and deflections resulting from drop tests of a mass with a flat impact surface onto flat pads of various elastomeric materials, and show that the forces can be predicted quantitatively with no adjustable parameters by using a theory whose only inputs are the linear viscoelastic characteristics of the material, measured in small-amplitude oscillatory deformations. The theory, which models the elastomer as a nonlinear neo-Hookean material, is accurate for several elastomeric solids including polyurethanes, polynorbornene, and poly-vinyl-chlorides (PVCs), over a wide range of impact velocities, masses, temperatures and pad thicknesses. The application in mind is the rational design of shock-cushioning pads and components in footwear and in portable equipment.
Goyal
S
S
Lucent Technologies Bell Laboratories, 600 Mountain Avenue, Rm. IB-212, Murray Hill, NJ 07974, USA. goyal@lucent.com
Larson
R G
RG
Aloisio
C J
CJ
D004548:Elasticity; D020724:Elastomers; D008962:Models, Theoretical; D055585:Physical Phenomena; D010825:Physics; D013696:Temperature
D020724:Elastomers