Modified damage equalization method for lifetime estimation of dielectrics

Abstract

This paper presents a modified Damage Equalization Method with statistical features for life estimation of dielectrics. The paper postulates damage as a random variable, which resulted in establishing a relationship between the Weibull scale, shape parameters and the endurance coefficient ‘n’ of inverse power law. By the modified DEM (m-DEM), for the first time, a range of values of n for each material is proposed, which is useful for design engineers. Until now, the endurance coefficient of inverse power law and strength constant were treated as constants. Here, it is shown that these coefficients do have statistical features or variations. Experiments are conducted on oil impregnated paper and LDPE samples using accelerated step-stresses for life estimation. The results of the estimation of endurance coefficient are compared with existing methods and reasonable conclusions are drawn in favor of the proposed method.