PROBLEM TO BE SOLVED: To provide a method for predicting a creep life, when both narrow- band random stress variations and narrow-band random temperature variations are applied on equipment.;SOLUTION: In the method for predicting the creep life of equipment under random stress variations and random temperature variations for obtaining the probability density function of the amount of damage accumulation, on the basis of a Robinson damage sum and to predict the life of the equipment on the basis of the probability density function, (1) a damage coefficient which expresses the amount of damage per unit time is approximated by a linear expression, when the random stress variations and random temperature variations lie within narrow bands, and (2) the random stress variations σ(t)(instant) are expressed by the sum of a time mean value σ(t)(mean) and probability amount of variations σ', and the random temperature variations θ(t)(instant) are expressed by the sum of a time mean value θ(t)(mean) and a probability amount of variations θ'(t).;COPYRIGHT: (C)2001,JPO
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