Patent ID: 6687624
Filing Date: 2004-02-03
Classification: G01N,G06F

Abstract:
A method for establishing a relationship between a strain &egr; and a stress &sgr; as a function of a loading time t of the stress &sgr; and a temperature T, comprising the steps:(i) determining a first function to describe a relationship between the stress &sgr; and the strain &egr; as a function of the temperature T, under short-term loading; (ii) determining a second function to describe a relationship between the strain &egr; and the stress &sgr; as a function of the loading time t, the temperature T and a Young's modulus E(T) dependent on the temperature T, under long-term loading; and (iii) establishing the Young's modulus E(T) as a function of the temperature T from the first function wherein the first function has the following form &sgr;(T,&egr;)=A1+A2+A3+A4 whereinA1=c1&egr;+c2&egr;3+c3&egr;5+c4ln(&egr;+{square root over (&egr;2+1)}) A2=c5&egr;T+c6&egr;T3+c7&egr;T5 A3=c8&egr;3T+c9&egr;3T3+c10&egr;3T5 andA4=c11&egr;5T+c12&egr;5T3+c13&egr;5T5.