METHOD FOR DETERMINING FAILURE TOUGHNESS OF MATERIAL Russian patent published in 1994 - IPC

FIELD: measurement technology. SUBSTANCE: method involves steps of loading a notched specimen, plotting the diagram of load F against displacement f of the load point when a crack appears at the top of the notch, increasing further the load until the crack begins to grow, recording the moment of the onset of the crack and the relative displacement parameter, calculating the failure toughness from the results obtained, plotting the diagram of toughness factor η against displacement f where h=(tgα_f/(tgα₀), α₀ is the slope of resilient loading line, α_f is the slope of the tangent to the failure diagram at the corresponding displacement, on the assumption that the moment of the onset of the crack corresponds to the value of displacement f related to the inflection point in the crack blunting and growing stages on the diagram. EFFECT: simplified test procedure, increased measurement results. 2 dwg