Application of a central design composed of surface of response for the determination of the flatness in the steel sheets of a Colombian steel

In this paper the results of research are shown in which the response surface was applied with central composite design for estimating the values of flatness as shown and accepted by the quality department and production company of the Caribbean region, taking into account factors such as voltage control in the winding sheet and the coefficient of friction. Initially, a first-order model was proposed to estimate the variance of the error and consider a quantitative model that takes into account the effects of combination. The method of steepest descent is used to sequentially move the descent path, i.e., in the direction of the minimum response decrement, until a new interval near optimal experimentation. Subsequently, a model of higher order was developed using a central composite design with center points and stars, taking into account control other variables additional response flatness, such as the roughness and hardness of the sheets in a range of flexible and acceptable tolerances for the company through a canonical model, and that will be the focus of future research

Database upscaling strategy for grain growth

Dataset corresponding to the paper "Energetic upscaling strategy for grain growth. II: Probabilistic macroscopic model identified by Bayesian techniques.

Imposed curvature of an elastic-plastic strip: application to simulation of coils

This work is part of the framework of a fast modeling of winding aiming at improving knowledge of residual stress evolution in steel strips and therefore their flatness during the coiling process. An exact analytical solution of an elastic-plastic strip with isotropic hardening at finite strains under an imposed transformation of curvature is developed. Issues related to flow rules for non-differentiable yield functions (Tresca) have been broached and a unique solution is obtained. The equivalence for this transformation, between von Mises and Tresca yield functions is demonstrated. This solution contributes to an efficient model by terms of computation times that aims at simulating coiling by taking into account inelastic deformations and enabling parametric studies in order to improve the process

Database upscaling strategy for grain growth

Dataset corresponding to the paper "Energetic upscaling strategy for grain growth. II: Probabilistic macroscopic model identified by Bayesian techniques.

Evaluation of contact stress during rolling process, by three dimensional analytical inverse method

International audienceA fully analytical three-dimensional inverse method has been developed in order to evaluate contact stress in the roll bite during rolling process. Stress measurements can be done by inserting fibre optics inside the roll body, (however no real measurements were available and simulations have been used instead). The inverse method takes as inputs three independent measured (or simulated) components of the stress tensor under the surface of the roll, and evaluates surface tractions of the roll especially in the contact in the roll gap. Stress, deformation and displacements can be obtained in the whole roll as well. This approach uses the theory of 3D isotropic elasticity and relies on displacement harmonic and bi-harmonic potentials expanded into a double Fourier series along the circumferential and axial directions. The identification of the solution involves matrices of size (3 × 3) computed off-line. This simple solution involves mainly the on-line computation of Fast Fourier Transform (fft) of three inputs, which takes 0.5 s for each (processor 2.8 GHz, time displayed by Scilab 5.3). Good accuracy is obtained, and the number of sensors along the axial direction is studied. Thus, this work encourages the development of an on-line industrial tool. © 2013 Elsevier Ltd. All rights reserved

An Experimental Technique For The Characterization Of Adhesive Joints Under Dynamic Multiaxial Loadings

International audienc

Characterization of roll bite heat transfers in hot steel strip rolling and their influence on roll thermal fatigue degradation

A temperature sensor with a thermocouple placed at ~0.5 mm from roll surface is used in hot rolling conditions to evaluate by inverse calculation heat transfers in the roll bite. Simulation analysis under industrial hot rolling conditions with short contact lengths (e.g. short contact times) and high rolling speeds (7 m./sec.) show that the temperature sensor + inverse analysis with a high acquisition frequency (> 1000 Hz) is capable to predict accurately (5 to 10 % error) the roll bite peak of temperature as well as the roll surface temperature evolution all around the roll rotation. However as heat flux is more sensitive to noise measurement, the peak of heat flux in the bite is under-estimated (20 % error) by the inverse calculation and thus the average roll bite heat flux is also interesting information from the sensor (these simulation results will be verified with an industrial trial that is being prepared). Rolling tests on a pilot mill with low rolling speeds (from 0.3 to 1.5 m./sec.) and strip reductions varying from 10 to 40 % have been performed with the temperature sensor. Analysis of the tests by inverse calculation show that at low speed (<0.5 m./sec.) and large contact lengths (reduction: 30 to 40%), the roll bite peak of heat flux reconstructed by inverse calculation is correct. At higher speeds (1.5 m./sec.) and smaller contact lengths (reduction: 10-20%), th