Dynamic Ring‐on‐Ring Equibiaxial Flexural Strength of Borosilicate Glass

Abstract

A novel dynamic ring‐on‐ring equibiaxial flexural testing technique with single pulse loading capability is established on a modified Kolsky bar. This technique is then utilized to investigate the loading‐rate and surface‐condition effects on the flexural strength of a borosilicate glass. Quasi‐static and dynamic experiments are performed at loading rates ranging from 5 × 10−1 to 5 × 106 MPa/s. It is found that the flexural strength of the borosilicate glass strongly depends on the applied loading rates. HF acid corrosion on the surface promotes the flexural strength to above 1.3 GPa. Fractographic analysis shows that surface modification has changed the type of flaws that govern the flexural strength of glass samples.

Micro- and macro-mechanical testing of transparent MgAl2O4 spinel

“…The validity of Eq. 5 is limited to a certain level of applied stress rates where the bending strength no longer increases with increasing stress rate [23,24]. In the current investigation, the loading rates appear to be too low to expect that the values get close to such an inert strength even at the highest used loading rates.…”

Deformation and damage mechanisms of laminated glass windows subjected to high velocity soft impact

“…This can be due to the higher 579 failure strain of glass under dynamic loading. Nie et al (2010) found that depending on the 580 surface condition of the glass, dynamic failure strain can be five times greater than its quasi-581 static value. The strain at location 2 is compared in Fig.…”

Dynamic Equibiaxial Flexural Strength of Borosilicate Glass at High Temperatures

“…For this reason, the edges were not further chamfered after flame polishing to avoid introducing new strength-limiting flaws. Results from previous room temperature equibiaxial ring-on-ring tests on the same material have revealed that the well-polished samples failed from pre-existing surface cracks [17], due to the fact that the flaws introduced by mechanical contact (grinding, polishing etc.) are dominant on the glass surface.…”

“…Recently, novel modifications to this wellrecognized apparatus have expanded its capability to the testing of a broader range of materials such as armor ceramics [16,19] and biological tissues [20,21]. The study in [17] described the implementation of ring-on-ring equibiaxial loading fixtures and single loading capabilities to a conventional Kolsky bar. For this new version of the Kolsky bar, the dynamic flexural strength of borosilicate glass was characterized with different surface modifications.…”

“…Therefore, surface cracks are considered to be responsible for the failure of this borosilicate glass material loaded in equibiaxial bending given that edge failure is not presented. In this study, a similar loading/supporting ring pair was adopted as previously been used in [17]. The diameters of those concentric rings are 12.5 mm and 25 mm, respectively, with a ring tip radius of 2.5 mm.…”