Development of a Finite Element (FE) based Model for the Prediction of the Width Spread of a Dog-Bone shaped Slab in Roughing Mill

MasterPrediction of the width spread of slabs and strips is important technique in hot rolling.A common practice in the roughing mill of hot rolling is to control the thickness and width of the slabs for the finishing mill. In the roughing mill, the dog-bone shape is formed at the edge of slab in the vertical rolling. And then a dog-bone shaped slab passes through the horizontal rolling.The width spread of a dog-bone shaped slab in the horizontal rolling affects the final width and product quality. Therefore, it is essential to predict the width spread of a dog-bone shaped slab in roughing mill.In this paper we present a model for the prediction of the width spread of a dog-bone shaped slab in roughing mill.The prediction model is developed based on the extremum principle(upper bound theorem) for rigid plastic material and a three-dimensional admissible velocity field.The prediction accuracy of the proposed model is examined through comparison with the predictions from the 3-D finite element (FE) simulations