Measurements of the Tensile Strength of Oils Under Dynamic Stressing

This paper reports measurements of the effective tensile strength (or ‘cavitation threshold’), F_c, of Newtonian silicone oils over a range of shear viscosities, and of a multigrade oil over a range of temperatures, T, in the range 20°C ≤ T ≤ 140°C. These measurements are the first to be obtained for a lubricant under dynamic stressing by tension, over a range of temperatures representative of those encountered under its normal operating conditions. This work introduces a method of estimating F_c from direct measurements of static positive pressures: it thereby eschews the reliance in previous related work upon direct measurements of dynamic negative pressures by transducers designed for use in the range of positive pressures.