Tensile failure of liquids under dynamic stressing

Abstract

This paper contains an account of various experiments associated with the propagation of a pressure pulse up a vertical column of liquid. When such a pulse reaches the upper free surface of the liquid it is reflected downwards as a pulse of tension. This method therefore provides a means of subjecting the liquid to tension under dynamic conditions of stressing. If the value of the tension at any depth exceeds a certain critical value the liquid will cavitate. Values of this critical tension T were measured for liquids of varying viscosities η and it was found that the empirical relation T=kη0.1 holds. Secondly, pulse propagation across the interface between two immiscible liquids was studied, and it was found that the maximum tension which could be sustained by an interface separating silicone oil and water is less than the tension which produces cavitation in either of these two liquids. Thirdly, it has been found that the cavitation produced shows several cycles of growth and collapse, a phenomenon which has been observed photographically by previous workers.

Dynamic tensile strength of silicone oils

“…This is not consistent with the experiments performed by Bull [9] as well as Couzens and Trevena [13] using bullet-piston arrangements, where they observed a power-law correlation between viscosity and critical tension (η 0.2 [9], η 0.1 [13], see Introduction). These correlations would have predicted a strength increase of 21 MPa and 9 MPa respectively between the low and high viscosity silicone oils.…”

“…By contrast, there is significant variability between the measured spall strengths in the work of Erlich and Utkin et al in glycerol. Figure 2b also contains data from bullet-piston experiments with glycerol [23] and silicone oils [13]. As can be seen, both the cavitation strength measurements and the strain rates are drastically lower than for spall experiments.…”

“…He attributed the observed increase in cavitation threshold as a function of viscosity to a larger resistance to viscous growth of voids [9]. Couzens and Trevena used a similar experimental arrangement and found a similar relationship (P s = kη 0.1 ) for a series of silicone oils having a three order of magnitude variation in viscosity [13]. In these studies, the strain rate was in the range of 10 2 s −1 [14] and the maximum tension was measured using pressure gauges on the wall of the liquid column.…”

Polymeric Hopkinson Bar-Confinement Chamber Apparatus to Evaluate Fluid Cavitation

“…This tensile reflection is limited by the amount of tension the fluid can withstand, showing a 'plateauing' of its magnitude with increasing compressive pulse magnitudes, and is reported as the apparent tensile strength of the fluid. This method is described in greater detail in the works of Couzen et al [54], Sedgewick et al [55], and Williams et al [56]. Couzen et al [57] reported tensile strengths of negative 0.912, 0.861, and 1.52 MPa for boiled water, tap-water, and boiled deionized water, respectively.…”

Cavitation and the tensile strength of liquids under dynamic stressing

“…Pulse reflection techniques Degassed distilled water: Davies et al [24] 10 bar [B-P] Degassed deionized water: Couzens and Trevena [25] 15 bar [B-P] Deionized water: Trevena and Couzens [26,27] 10 bar [B-P Deionized water: Richards et al [28] 12 bar Distilled water: Crum and Fowlkes [29] 12 bar Ordinary tap water: Couzens and Trevena [25] 8.5 bar [B-P] Ordinary tap water: Bull [30] 15 bar [B-P] Ordinary tap water: Wilson et al [31] 8 bar B-P denotes work involving the 'bullet-piston' technique and its derivatives.…”