Patent ID: 7930112

Claim:
A method for evaluation of measured values for the recognition of defect conditions due to material fatigue on aircraft parts, in which strain sensors ( 6 ) are applied on the critical locations of an aircraft ( 1 ) or its parts, whereby the measured values of the strain sensors are detected at different loading conditions through several measuring circuits, are amplified, and are stored, and from which an evaluating apparatus ( 9 ) derives, signals or indicates a material fatigue through comparison of current measured values with previous measured values, characterized in that the critical aircraft parts ( 1 ) are impinged on with a plurality of prescribed loading conditions by a plurality of externally acting loading elements ( 3 ), and in that the strain effect caused thereby is detected through a plurality of measuring circuits including strain gages as the strain sensors, and the evaluating apparatus ( 9 ) for at least each loading condition and each measuring circuit forms an allocated reference value and a permissible limit value range, whereby, according to the detected strain measured values (X M ) for each loading condition, from at least the first existing current measured values for each measuring circuit these are evaluated as reference values (X R ) and therefrom an absolute limit value range is calculated for each reference value (X R ) through prescription of a permissible deviation (n GW % ), which limit value range is subsequently coupled with the current measured values so that the exceeding of the limit value range by at least one current measured value represents occurrence of a material fatigue manifestation.