Establishment Of The Joule Heating Bending Plate Process Heat Source Model And Experimental Verification

To quickly build hull shell of high performance and low resistance is difficult since the beginning of modern shipbuilding. Traditionally, the hull shell is achieved by line-heating process. By using oxyacetylene flame fast heating and water rapid cooling, this process makes the steel plate under the condition of plastic strain, and ultimately form a complex two-way curved surface.This paper aims at improving the efficiency of line-heating process, by directly import high power DC current into the steel. The resistance of the steel plate, will form internal heat source which is similar to the effect of oxyacetylene flame. This kind of heat source has fewer heat reflection and radiation than the traditional one, thus can greatly improve the utilization rate of energy. The new heat source can form complex curved surface, much more easy to control than the traditional source,and totally no pollution. These advantages make resistance heat source easier to implement automation, and has broad application prospection.This paper establishes numerical model of the joule heat source,and then designs experiment to verify the model.Firstly, the effect of joule-heat process parameters on the current density has been studied, then a numerical model of the typical electrode is set up. Through a large number of simulation, comparison and analysis electrode characteristics, plate parameters, and screen out the most important process parameters, electrode spacing, and found that the rectangular electrode is most representative of the typical electrode form. The subsequent heat source model is established depend on it.Secondly, by analyzing the numerical simulation results of steel electric with two-way coupling concluded that two-way coupling cannot be ignored, and the heat capacity and the thermal conductivity can be regarded as constant. Based on a number of electro-thermal coupling numerical simulation results and fitting, eventually establishes the numerical model of the joule-heat source;Thirdly, design experiments to validate the thermal resistance model. Through scientific experiments verify joule-heat source to replace the oxyacetylene flame is feasibility, found the other phenomena and specific laws about joule-heat source.In the end of this thesis summarized the research results and deficiencies, and discussed the joule-heat source in further study and industrial application.