On the Multi-Parameter Experimental Investigation of Curing Cycle for Glass Fabric/Epoxy Laminated Composites

In this study, a multi-parameter analysis, using Taguchi method for design of experiments, has been conducted to investigate the optimum curing conditions for E-glass fabric/epoxy laminated composites. The independent variables in the L₂₅ Taguchi orthogonal array were heating rate a, curing temperature T_C and curing time t_C, including five levels each. Tensile and 3-point bending tests were performed for each experiment number (run number) of the Taguchi L₂₅. In this study, the significant factors for both tensile and flexural performance were temperature and time at 95% confidence level. Specifically, the tensile performance was affected almost equally by both curing temperature and time (32.71% and 35.89%, respectively). The flexural performance was mostly affected by curing temperature (44.02%) and secondarily by curing time (31.52%).

The use of Poisson regression method, combined with backward elimination, has been introduced to increase the accuracy of the multiple regression model. In fact, the accuracy (R²) of the Poisson Regression model was greater than 97%, when the respective one of the commonly used Multiple Regression models tested was about 65%-70%. Specifically, using Poisson Regression Model, in the case of tensile model R² was equal to 97.05% and in the case of flexural model R² reaches the value of 98.11%.