Design allowable for durability analysis of advanced composites

An allowable design method is presented, along with its experimental validation, to obtain engineering-standard design allowable for fatigue life evaluation of advanced composites. A small sample test method for stress/life curves was established to overcome these issues based on the regression analysis theory. Statistically-based design values, such as the B-basis value, the Anderson-Darling test statistic and the observed significance level, were obtained depends on the characteristics of the composite material test data. For evaluation of the fatigue life of advanced composites, the S-N curve-fitting parameters are obtained using the linear heteroscedastic regression method based on experimental data. Another advantage of this method is that all the test data at different stress levels can be analyzed coinstantaneously, which greatly saved the experimental efforts and specimen for confidential statistical results. Finally, an experimental test program has been conducted on typical laminate composites to generate statistically meaningful data for durability design. The numerical results show that the proposed method can be used as a guide to obtaining design allowable for durability analysis of advanced composite structures.