| 摘要 |
PURPOSE:To estimate the residual life of the strength of a structural material to stress in a non-destructive manner, by estimating the change in coefficient of X-ray absorption with the elapse of time. CONSTITUTION:The relation of the deterioration in strength sigma to a time (t) and that of a hard X-ray absorption coefficient change ratio DELTAmu to the time (t) are calculated at least at four points or more in a non-destructive manner by actual measurement. Next, the relation of the strength lowering ratio DELTAsigma to the hard X-ray absorption coefficient change ratio DELTAmu is calculated as DELTAsigma=aDELTAmu<b> [(a) and (b) are constants]. Because residual strength sigma is a value calculated by subtracting the strength lowering ratio DELTAmu from initial strength sigma0, a material reaches its life at the point of time when residual strength sigma reaches the max. stress sigmad applied to the material or less. |
