SYNTHESIS OF OPTIMAL CONTROL OF FEED-BACK SYSTEM FOR NUMERICAL MODEL OF INDUCTION HEATING PROCESS OF THE STEEL CYLINDRICAL BILLETS

Author(s):  
Maria Artur
2012 ◽  
Vol 28 (02) ◽  
pp. 73-81
Author(s):  
Xue-biao Zhang ◽  
Yu-long Yang ◽  
Yu-jun Liu

In shipyards, hull curved plate formation is an important stage with respect to productivity and accuracy control of curved plates. Because the power and its distribution of induction heat source are easier to control and reproduce, induction heating is expected to be applied in the line heating process. This paper studies the moveable induction heating process of steel plate and develops a numerical model of electromagneticthermal coupling analysis and the numerical results consistent with the experimental results. The numerical model is used to analyze the temperature changing rules and the influences on plate temperature field of heating speed of moveable induction heating of steel plate, and the following conclusions are drawn. First, the process of moveable induction heating of steel plate can be divided into three phases of initial state, quasi-steady state, and end state. The temperature difference between the top and bottom surfaces of the steel plate at the initial state is the biggest; it remains unchanged at the quasi-steady state and it is the smallest at the end state. Second, obvious end effect occurs when the edges of the steel plate are heated by the inductor, which causes a decrease in temperature difference between the top and bottom surfaces of the steel plate that is unfavorable for formation of pillow shape plates. Third, with the increase of heating speed, the temperature difference between the top and bottom surfaces of the steel plate increases gradually.


2004 ◽  
Vol 19 (1-4) ◽  
pp. 51-56 ◽  
Author(s):  
Alexandre Masserey ◽  
Jacques Rappaz ◽  
Roland Rozsnyo ◽  
Rachid Touzani

Author(s):  
Natalya A. Il`ina

The formulation and method of solution of the problem of time-optimal control of induction heating process of an unlimited plate with two control actions on the value of internal heat sources with technological constraint in relation to a one-dimensional model of the temperature field are proposed. The problem is solved under the conditions of a given accuracy of uniform approximation of the final temperature distribution over the thickness of the plate to the required. The method of finite integral transformations is used to search for the input-output characteristics of an object with distributed parameters with two control actions. The preliminary parameterization of control actions based on analytical optimality conditions in the form of the Pontryagin maximum principle is used. At the next stage reduction is performed to the problem of semi-infinite optimization, the solution of which is found using the alternance method. The alternance properties of the final resulting temperature state at the end of the optimal process lead to a basic system of relations, which, if there is additional information about the shape of the temperature distribution curve, is reduced to a system of equations that can be solved. An example of solving the problem of time-optimal control of temperature field of an unlimited plate with two offices is carried out in two stages. At first stage the case of induction heating without maximum temperature constraints is considered, at the second stage is carried out on the basis of the results of the first stage to obtain the solution subject to the limitation on the maximum temperature of the heated billet.


2004 ◽  
Vol 40 (3) ◽  
pp. 1664-1671 ◽  
Author(s):  
A. Masserey ◽  
J. Rappaz ◽  
R. Rozsnyo ◽  
R. Touzani

2021 ◽  
Author(s):  
Bernd-Arno Behrens ◽  
Hendrik Wester ◽  
Stefan Schäfer ◽  
Christoph Büdenbender

Multi-material solutions offer benefits, as they, in contrary to conventional monolithic parts, are customised hybrid components with properties that optimally fit the application locally. Adapted components offer the possibility to use high strength material in areas where external loads require it and substitute them by lightweight material in the other areas. The presented study describes the manufacturing of a hybrid shaft along the process chain Tailored Forming, which uses serial pre-joined semi-finished products in the forming stage. Subject of this study is the numerical modelling of the heating process by induction heating of a hybrid semi-finished product and the resulting material distribution after the impact extrusion process. For this endeavour, a numerical model of an inhomogeneous induction heating process was developed. The main challenge is to determine the boundary conditions such as current intensity acting in the induction coil and the electromagnetic properties of the used material. The current intensity was measured by a Rogowski coil during experimental heating tests. The relative magnetic permeability was modelled as a function of temperature using the method of Zedler. The results show the importance of using a relative magnetic permeability as a function of temperature to guarantee a high quality of the numerical model. Subsequently, the model was applied to the heating of the hybrid semi-finished product consisting of a steel and aluminium alloy. By using inductive heating and thus a resulting inhomogeneous temperature field, good agreement of the material distribution between experiment and simulation could be achieved after the forming process.


Author(s):  
Xuebiao Zhang ◽  
Cheng Chen ◽  
Yujun Liu

In shipyard, triangle heating technology with irregular multi-heating paths and highly concentrated heat input is used to form a curved plate, especially a concave type plate. Compared with line heating process with simple line segment path, its main purpose is to get a bigger contraction deformation at the plate edge. Hence, triangle heating technology is important for most shipyards to increase hull-forming productivity and study the automation. This paper focuses on the moveable triangle induction heating technology. An electromagnetic coupling finite element model is built to simulate the moveable triangle induction heating process and reveal the temperature characteristics and deformation behavior. The results of the simulation are compared with those obtained from experiments and show good agreement. It demonstrates that the numerical model used in this study is effective for simulating triangle heating for the steel plate forming process in shipbuilding. With the numerical model, the paper further investigates the effect of heating parameters on temperature and shrinkage deformation. These are traced here with a modified mechanical model whose results are in accord with the numerical results. This modified model can be applied to predict the edge shrinkage and explain the effect of heating parameters on transverse shrinkage.


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