Development of novel models for fatigue life assessment of natural rubber/styrene-butadiene rubber/nanoclay nanocomposite

In the present work, multiple regression models are established for assessing the fatigue life of nanoclay nanocomposites comprising natural rubber (NR) and styrene-butadiene rubber (SBR). Quadratic (for two factors) and reduced cubic (for three factors) regression models have been applied to create the NR/SBR/nanoclay durability models, and the goodness of fit, homoscedasticity, and normality of the models were evaluated. Also, an analysis of the influence factors on the fatigue life of NR/SBR/nanoclay nanocomposites was done. Various factors were chosen for the investigation: strain amplitude, nanoclay loading, and test frequency. By creating the effects model, the main effects and the interactions of each factor on the fatigue life of the nanocomposites were considered. A statistical analysis of the quadratic model revealed that the strain amplitude has the most significant effect on the fatigue life of rubber samples. The variance analysis of the reduced cubic model showed that the nanoclay loading and the test frequency have the most negligible effect on the rubber samples' fatigue life, respectively. Despite the significant main impact of the studied factors, the 2-way interaction, as well as the 3-way interaction of the variables, was not effective in the reduced cubic fatigue life model.