TITLE:
Viscosity Transient Phenomenon in Drop Impact Testing of Soft Material
AUTHORS:
Chen Liu, Yukio Fujimoto, Yoshikazu Tanaka, Eiji Shintaku, Toshiki Nakanishi
KEYWORDS:
Strain Rate Dependence, Soft Material, Impact Force, Thorn-Shape Waveform, Viscosity Transient, Standard Linear Solid (SLS) Model, Flat Frontal Impact
JOURNAL NAME:
World Journal of Mechanics,
Vol.6 No.5,
May
9,
2016
ABSTRACT: The authors carried out drop impact tests for several soft materials
under a flat frontal impact condition in which a drop hammer with a flat bottom
surface strikes a plate-like soft material in the normal direction. The
experimental results indicated that the impact force waveforms of soft
materials consisted of a thorn-shaped waveform and a subsequent mountain-shaped
waveform. The thorn-shaped waveform was strongly affected by the strain rate.
In the present study, the occurrence mechanism of this distinctive waveform was
discussed from the viewpoint of the viscosity
transient phenomenon. A standard linear solid (SLS) model in which the
viscosity transient phenomenon was considered was applied to the simulation.
Some features of the impact force waveform of soft materials could be explained
by the SLS model. Furthermore, the thorn-shape waveform could also be observed
in the impact force waveforms of human skin and free-falling hollow
balls.