Quantification of coil slippage during initial coiling with belt wrapper

Abstract

The finite element model and mathematical model for the coiling process with the belt wrapper have been developed by simplifying the belt wrapper to copy the strip head end positioning on free tension reel shortly, known as the initial coiling. The models have tried to quantify the coil slippage that makes a scratch on the coil. However, it is hard to compare the models to the real operation due to some assumptions. Moreover, computations is increased dramatically if the model includes the real operation such as non-linear property of the belt wrapper. This study suggests new modelling approach without the belt wrapper to quantify the coil slippage according the compression on the coil. Instead of the belt wrapper, all nodes of the strip are controlled by specific x-y displacements as the belt wrapper compresses the strip coil. Different x-y displacements of each node can change the magnitude of the compression by the belt wrapper. A finite element model of the initial coiling was simulated by the modelling approach and Model Change technique in ABAQUS, and discontinuous processes including removal of the belt wrapper and the application of coiling tension, σ are proceeded in consecutive order. By doing parametric analysis regarding the radial deformation of the coil by the belt wrapper, rd and σ, the coil slippage happens frequently when σ is below critical value or when rd is large. This phenomenon is similar to the spring back, so σ should be high or should be applied before the belt wrapper is removed. This indicates that, rd should be manipulated carefully because the coil slippage happens as rd increases. Besides the initial coiling, the modelling approach can be applied to other problems that need many computations such as the 300 layers of strip lamination.