Modelling of the Mannesmann effect

The paper presents a new model of the Mannesmann effect. The model is based on a novel damage law that takes into account the effects of pre-existing defects in the working material. Thanks to this feature, the model is capable of making accurate predictions of the location where the fracture will appear under the action of external loading as well as of the time it takes to be generated. An application of the model to a rotary tube piercing operation carried out at elevated temperature is presented and commented.