Modeling the collapse of coiled material

After processing many strip materials are wound or coiled. Winding the material on a mandrel under tension introduces residual stresses in the coil. These stresses and interlayer movement can lead to large deformation and collapse of the coil. Here a finite element analysis is used to examine the stresses and deformation in large coils. A nonlinear jointed material model is used to represent the interlayer sliding and opening. The analysis of coils under different boundary conditions shows that patterns of coil deformation resembling coil collapse can occur.