Application of slitting method to characterize the effects of thermal fatigue, lay-up arrangement and MWCNTs on the residual stresses of laminated composites

Residual stresses in engineering components can have a profound effect on service performance, particularly fatigue life. In this research, the effects of consequential parameters on the thermal residual stresses of glass fiber reinforced polymer (GFRP) composite structures such as thermal cycle fatigue, lay-up configuration and addition of multi-walled carbon nanotubes are characterized experimentally. The slitting method is performed to measure the non-uniform residual stresses over the thickness. Additionally, an extended finite element modeling is carried out to simulate the slitting process. Experimental results indicated that residual stress quality of the composite profiles can be considerably affected by thermal fatigue condition. It was observed that thermal residual stresses decrease with increment of the number of thermal cycles. It was also revealed that symmetric lay-up arrangements show less residual stresses than the unsymmetrical ones.