Study On Numerical Simulation Of General Expression Of Double Ellipsoidal Heat Source Model

The welding heat source model plays an important role in numerical simulation,and makes great influence on the numerical simulation of welding temperature fields.Goldak double ellipsoidal heat source model was widely applied to the numerical simulation of fusion welding processes.However,the heat flux distrubution parameter are fixed values,which is not satisfied any more for some welding processes.In order to improve the accuracy of numerical simulation, Goldak double ellipsoidal heat source model was uesd in the numerical simulation of welding temperature flields of automatic MAG.Based on the experiments,the paper analysis the temperature fileds results and adjusts heat flux heat flux distrubution parameter values and to make a study on the general expression of double ellipsoidal heat source model.Based on the analysis of characteristic of the general expression of double ellipsoidal heat source model parameters, the influence of parameter values on temperature are investigated. The main conclusions were shown as following:double ellipsoidal heat source model parameters、thermal efficiency and heat flux distrubution parameter values have a significant impact on the numerical simulation results.In order to abtain a more excellent result, we can adjust the thermal efficiency and heat flux distrubution parameter values in the optimal processes.The mechanism of the influence made by thermal efficiency and heat flux distrubution parameter on the energy distrubution are investigated.The results show that the thermal efficiency has an impact on numerical simulation results by making influence on the heat input of weld metal area、heat-affected zone and base metal and heat flux distrubution parameter by making influence on energy degree of concentration in the weld zone.In addition, the relationship between values of thermal efficiency and heat flux distrubution parameter and simulation results are summarized and the empirical formula to calculate the relationship between thermal efficiency and heat flux distrubution parameters with temperature fields are derived,to lay the foundation for the general expression of double ellipsoidal heat source model.Finally,based on the above conclusions,using general expression of double ellipsoidal heat source model to simulate the welding fields of automatic MAG.The main conclusions were shown that compared with the results computed by the Glodak double ellipsoidal heat source,the values computed by the general expression of double ellipsoidal heat source were shown to be a more excellent agreement with the experimental values under the same welding conditions.In addition,the heat source model alse fit the SMAW welding fields,which are verified by the corresponding welding processes.