Shear stiffening gel under low-speed impact: Mechanical behavior characterization and protective performance analysis

According to the controlled shear rate (CSR) test, the shear stiffening gel (SSG) exhibited viscoelastic behavior, which can be fully described by the general Maxwell model. A specific analytical model was established to identify the material parameters automatically based on simulated annealing (SA) optimization. Besides, according to the CSR tests under different temperatures, the influence of temperature and strain rate on the mechanical behavior of SSG was assumed to be decoupled. And an applicable engineering relation was introduced for parameter adjustment of the Maxwell model near room temperature. The reliability of the material parameters was verified through the results comparison of the low-speed impact tests of SSG and corresponding FE simulations. Based on field analysis of the FE simulations, the mechanism of the stress dispersion ability of SSG was elaborated. A feasible design idea was introduced to fully utilize this property. In order to verify the effectiveness of the design idea, a series of egg impact tests were developed, conducted, and analyzed. And the protective idea proved helpful in fully invoking the stress dispersion potential of SSG assembly for impact protection and improving the lightweight design.