Analytical inverse solution for coupled thermoelastic problem for the evaluation of contact stress during steel strip rolling

Abstract Knowledge of the contact stress between roll and strip is a critical factor in modern, high-speed rolling mills. Previously two inverse analytical methods have been developed to determine the elastic contact stress on the one hand and the heat flux or the temperature in the whole roll (and especially at the surface) on the other hand, by measuring the stress tensor inside the roll body with fibre optics and by measuring the temperature with a thermocouple fully embedded at only one point inside the roll. However measurements done by fibre optics take into account the elastic stress and the thermal stress. However the contact stress was determined under isothermal assumption, which is strongly incorrect for hot rolling conditions. In this paper, the coupled thermoelastic problem is solved analytically using the theorem of superposition and the expression of the temperature field exhibited previously. A significant improvement of the accuracy of the inverse method for reconstructing the contact stress is observed by taking into account thermal stress. Hot rolling simulation is given to demonstrate this result. The computation time is studied to rapidly optimise the industrial parameters during the rolling process, and considering that both inverse methods have been run, the computation of thermal stress does not cost significant additional CPU times.

[1]  Nicolas Legrand,et al.  Analysis of Roll Gap Heat Transfers in Hot Steel Strip Rolling through Roll Temperature Sensors and Heat Transfer Models , 2012 .

[2]  Pierre Montmitonnet,et al.  Coupled approach for flatness prediction in cold rolling of thin strip , 2011 .

[3]  Guo-dong WANG,et al.  Numerical Simulation of Temperature Field and Thermal Stress Field of Work Roll During Hot Strip Rolling , 2007 .

[4]  Ahmad Saboonchi,et al.  Work roll thermal expansion control in hot strip mill , 2008 .

[5]  Pierre Montmitonnet,et al.  Hot and cold strip rolling processes , 2006 .

[6]  Saeed Setayeshi,et al.  Prediction of influence parameters on the hot rolling process using finite element method and neural network , 2009 .

[7]  N. Legrand,et al.  New concept of friction sensor for strip rolling: Theoretical analysis , 2012 .

[8]  M. Wang,et al.  Analysis of coupled mechanical and thermal behaviors in hot rolling of large rings of titanium alloy using 3D dynamic explicit FEM , 2009 .

[9]  A. Ehrlacher,et al.  Experimental Study of Interfacial Heat Flux and Surface Temperature by Inverse Analysis with Thermocouple (Fully Embedded) during Hot Steel Strip Rolling , 2012 .

[10]  A. Ehrlacher,et al.  Evaluation of temperature field and heat flux by inverse analysis during steel strip rolling , 2012 .

[11]  Nicolas Legrand,et al.  A new sensor for the evaluation of contact stress by inverse analysis during steel strip rolling , 2011 .

[12]  R. Colás,et al.  Modeling the thermal and thermoelastic responses of work rolls used for hot rolling steel strip , 2004 .

[13]  A. K. Tieu,et al.  Modelling of the rolling processes by a 3-D rigid plastic/visco-plastic finite element method with shifted ICCG method , 2001 .

[14]  A. Peirce.  Computer Methods in Applied Mechanics and Engineering , 2010 .