Strain-rate dependence of the tensile strength of glass fibers

Abstract

It is well known that the strength of glass fibers increases with increasing strain rate. Consequently, impact strength of glass fiber is competitive with that of carbon fiber. This strengthening phenomenon is well recognized for bulk glass. Strain-rate dependence of the strength for bulk glass was described by considering slow crack growth in glass. The analytical model that considered the slow crack growth of glass is proposed to predict the strength of glass fibers. The proposed model considered the stress corrosion limit and a constant crack velocity region. Calculations showed almost same results with the previous model, however, some differences were confirmed. To discuss the validity of the analysis, tensile tests of E-glass fiber bundles were conducted at various strain rates. It was observed that the fracture behaviors differ with the strain rates. Experimental results showed that the strength of E-glass fibers increased with increasing strain rate. Furthermore, we confirmed that the analytical results were in good agreement with the experimental results. The strain-rate dependence of the strength of glass fibers was successfully predicted by considering the slow crack growth in glass.

A novel model to predict the stiffness and strength of unidirectional glass/epoxy composites at different strain rates

“…A similar observation by utilizing a tension split Hopkinson pressure bar and a high-speed tensile-testing machine over the strain rate from 8.33 × 10 −4 to 500 s −1 was reported by Taniguchi et al. 28,29 They observed that by increasing the strain rate from the quasi-static condition to 50 s −1 , the ultimate strength increased significantly; while beyond this strain rate, the increasing rate was declined. Nevertheless, the increasing ratio of the strength from the quasi-static condition to the strain rate of 250 s −1 is about 60%.…”

“…By having material constants (ψ and ξ) and Young's modulus ( E ), the mechanical behavior of glass fibers at different strain rates can be predicted. However, experimental data 26–29 showed that Young's modulus of glass fibers is a rate-dependent parameter and increased by increasing the strain rate. To account for the rate dependency, equation (4) needs some modifications to include a strain rate-dependent elastic modulus instead of a constant one.…”

“…The glass fibers are the most commonly used reinforcing fibers in the fabrication of polymer matrix composites. In this section, to investigate the influence of the strain rate on the stress-strain behavior of the glass fiber as a rate-sensitive material, [26][27][28][29] using the modified Maxwell model in combination with semi-empirical equations, a new viscoelastic constitutive equation was introduced. To complete this part of the model, the simplified Cowper-Symonds material model was combined with the present viscoelastic constitutive equation to predict the strain-rate dependent strength of glass fibers.…”

“…Experimental data [26][27][28][29] showed that the strain rate significantly affects the overall mechanical behavior of glass fibers. In the present study, based on the empirical evidence, [26][27][28][29] the Maxwell model was utilized to model the mechanical behavior of glass fibers. In the Maxwell model, a spring and a damper in series were used to model the elastic and viscoelastic behavior of the material, respectively.…”

Fatigue analysis of carbon, glass and other fibres

“…Using fibre bundles for testing can solve this problem to some extent but usually leads to another problem, friction between the fibres (Arao, Taniguchi, Nishiwaki, Hirayama, & Kawada, 2012). Typically the diameter of a fibre is in the range of 5e10 mm, making it very difficult to apply a true axial cyclic stress to a single fibre.…”