Study of shear-stiffened elastomers

Abstract

Shear thickening fluids, which are usually concentrated colloidal suspensions composed of non-aggregating solid particles suspended in fluids, exhibit a marked increase in viscosity beyond a critical shear rate. This increased viscosity is seen as being both 'field-activated', due to the dependence on shearing rate, as well as reversible. Shear thickening fluids have found good applications as protection materials, such as in liquid body armor, vibration absorber or dampers. This research aims to expand the protection material family by developing a novel solid status shear thickening material, called shear-stiffened elastomers. These new shearstiffened elastomers were fabricated with the mixture of silicone rubber and silicone oil. A total of four SSE samples were fabricated in this study. Their mechanical and rheological properties under both steady-state and dynamic loading conditions were tested with a parallel-plate. The effects of silicone oil composition and angular frequency were summarized. When raising the angular frequency in dynamic shear test, the storage modulus of conventional silicone rubber shows a small increasing trend with the frequency. However, if silicone oil is selected to be mixed with silicone rubber, the storage modulus increases dramatically when the frequency and strain are both beyond the critical values. © 2013 AIP Publishing LLC. Abstract. Shear thickening fluids, which are usually concentrated colloidal suspensions composed of non-aggregating solid particles suspended in fluids, exhibit a marked increase in viscosity beyond a critical shear rate. This increased viscosity is seen as being both 'field-activated', due to the dependence on shearing rate, as well as reversible. Shear thickening fluids have found good applications as protection materials, such as in liquid body armor, vibration absorber or dampers. This research aims to expand the protection material family by developing a novel solid status shear thickening material, called shear-stiffened elastomers. These new shear-stiffened elastomers were fabricated with the mixture of silicone rubber and silicone oil. A total of four SSE samples were fabricated in this study. Their mechanical and rheological properties under both steady-state and dynamic loading conditions were tested with a parallel-plate. The effects of silicone oil composition and angular frequency were summarized. When raising the angular frequency in dynamic shear test, the storage modulus of conventional silicone rubber shows a small increasing trend with the frequency. However, if silicone oil is selected to be mixed with silicone rubber, the storage modulus increases dramatically when the frequency and strain are both beyond the critical values.

Fabrication and Characterization of Isotropic and Anisotropic Magnetorheological Elastomers, Based on Silicone Rubber and Carbonyl Iron Microparticles

“…The experimental curves of G′ and G″ shown in Figure 8 are in good agreement with experimental results reported in [31], where a novel shear-stiffened elastomer fabricated with a mixture of silicone rubber and silicon oil were analyzed by dynamic loading conditions, with a parallel-plate rheometer. Furthermore, and from the experimental data illustrated in Figure 8, it is also possible to plot the damping factor dependence, tanδ versus the frequency f , as well as the Cole–Cole diagram (G″ vs. G′).…”

“…The peaks observed in the tanδ curves correspond to the damping terms of the FZM, which are related to the mechanical relaxation peaks, while Figure 4b shows how the slope of the Cole–Cole diagram can be used to predict the fractional parameter values of a and b. The theoretical curves obtained for both G′ and G″ could be compared with experimental data to describe the main relaxation process of amorphous polymeric materials, as discussed in [30,31,32]. Notice that G′ is a curve that depends on the frequency.…”

Rheology of crosslinked entangled polymers: Shear stiffening in oscillatory shear

“…After decades of research, it is found that its non‐Newtonian characteristics make it possible for more intelligent applications. For example, it can be used as a shock‐absorbing component on airplanes and automobiles, or as protective materials, damping materials, packaging materials, and so on for military or civilian use . In order to better realize the practical value of shear‐stiffening polymer, it is necessary to study the specific factors that affect the shear‐stiffening effect of the polymer.…”

Rate-dependent and self-healing conductive shear stiffening nanocomposite: a novel safe-guarding material with force sensitivity

“…[26,27] nanowires-based wearable multifunctional sensors which could detect strain, pressure and finger touch with fast response time and high sensitivity. [31,32] Based on the unique mechanical properties, ST materials have been applied in vibration controlling, damping and body armor. Due to the sensitive rate dependent property, a number of attention has been paid to develop high performance ST materials.…”

“…Due to the sensitive rate dependent property, a number of attention has been paid to develop high performance ST materials. [32] Based on the ST gel, Palmer R. developed a new kind of body armor which could absorb much energy during impact. [31,32] Based on the unique mechanical properties, ST materials have been applied in vibration controlling, damping and body armor.…”