Reliability analysis for composites ― corrosion-resistant data

摘要

JIS K 7020 describes three estimation methods, the first of which is method A; covariance method, the second, method B; regression with time as independent variable, the third, method C; second order of polynomial expression. All three methods induce equation by putting 'time' as independent variable It is reasonable to take time' as a major factor for deterioration but we can not simply conclude the effect of time whether or not to take the 1st order, the 2nd order or another more higher order form or their mixtures. Also, coefficients vary for every estimation by degree because of the dependence among variables In order to avoid these weakness, it is useful to apply calculation by development of orthogonal polynomial expression (Chebyshev's orthogonal function). Following up the preceding 1st report for HC1 immersion data this time on the basis of analysis for HNO_3 immersion data, the paper features reliability research for composite materals through comparing differences with usual simple estimation method, and confirming reappearance of the analysis.