This paper comments on using the Larson-Miller parameter to fit the creep-rupture life distribution as a function of temperature and stress. The commonly used least-squares linear regression method assumes that the creep-rupture life follows the lognormal distribution. Most engineering literature does not discuss the validity of this assumption. In this paper, we outline the procedure for validating two critical assumptions when the least-squares method is used. The maximum likelihood method is suggested as an alternative and more powerful method for fitting creep-rupture life distributions. Examples are given to demonstrate the use of these two methods using Microsoft Excel and the LIFEREG procedure in SAS. [S0094-9930(00)00504-7]
Issue Section:Technical Papers
Keywords:creep, creep testing, pressure vessels, Creep, Larson-Miller Parameter, Data Analysis, Life Distribution, Least-Squares Method, Maximum Likelihood Method
Topics:Creep, Fittings, Rupture, Stress, Temperature
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