Patent ID: 8082799

Claim:
A method for determining the extent of cyclic stress fatigue suffered by a component comprising the steps of: (i) providing a strain gauge whose surface undergoes a decrease in reflectivity in response to application of repeated strain cycles to the gauge, the strain gauge comprising a gauge material which undergoes a continued progressive/cumulative and quantifiable decrease in reflectivity in response to repeated strain cycles applied to said gauge material said decrease in reflectivity of the gauge material being indicative of both the degree of strain and the number of cycles incurred during said repeated strain cycles; (ii) determining a correlation between the extent of the decrease in reflectivity of the surface of the strain gauge and the effect on said component of the corresponding number and degree of strain cycles; (iii) affixing said strain gauge to said component to subject said strain gauge to any strain encountered by an adjacent portion of said component; (iv) at least periodically determining said decrease in reflectivity of said strain gauge to determine said extent of cyclic stress fatigue of said component.