Application of statistical design of experiments to thermoplastic tape laying

A tape laying head for in-situ consolidation of thermoplastic matrix composites was designed using a computer model. The computer model predicts interlaminar bonding as a function of head temperature, pressure, and speed. A statistical experiment was conducted to demonstrate the functionality of the tape laying head and to provide additional information on the process. Short beam shear test specimens (from APC-2 AS4/PEEK prepreg tows) were manufactured under various head temperature, pressure, and speed combinations. A linear model was assumed over the ranges of head temperature, pressure, and speed selected. Bond quality was determined quantitatively by short beam shear test results and qualitatively by photo micrographs. By using the statistical design of experiments approach, a minimum number of tests were required to validate the head design over a range of process conditions.