Study of the Automated Process-Induced Residual Stresses in Multi-Axis Laminates

Abstract

The integrity of the composite structures is affected by the manufacturing conditions. Controlling the ply orientation during the manufacturing process plays an important role in defining the induced residual stresses inside the laminate. This work evaluates the generated residual stresses inside multi-axis laminates of carbon fiber reinforced polymers. The samples are manufactured using the robotic fiber placement technique. The residual stresses are measured through the incremental hole-drilling method. Finite element modeling is used to provide the calibration process of the strain measurements. Additionally, microstructure analyses have been performed to show the configuration of the manufactured samples. The effect of the laminate configurations and plies orientations are investigated and compared. The layers’ orientations have shown a considerable effect on the generated stresses.