Slitting Measurement of Residual Hoop Stresses Through the Wall-Thickness of a Filament Wound Composite Ring

摘要

The slitting method was used to determine residual hoop stress profile along the thickness of a filament wound carbon/epoxy ring. The method involves measuring strains at the inner surface of the ring, while a narrow axial slit is cut progressively from the outer surface. In order to calculate the residual hoop stress profile over the entire ring thickness, pulse method was used, which assumes that stress in each depth increment is uniform. Besides, Tikhonov regularization was employed to stabilize the stress results and reduce its sensitivity to strain measurement errors. Regarding the fact that Tikhonov regularization is not appropriate for computing solutions with discontinuities, pulse method coupled with Tikhonov regularization was used separately for each layer of the composite ring.