Design And Application Research About Numerical Simulation And Material Control System Of Laser Welding

In recent years, Automobile industry has developed rapidly with the growth of national economy. Economical cars become consumers’most favorite selection by their light weight, less fuel consumption, and high safety. More and more Laser Tailor Welded Blanks(LTWB) are used in automobile factories, the applications of LTWB reduced body mass and production costs.In addition, laser welding is also widely used in buildings, bridges, appliances and other fields.Whereas, laser welding simulation, optimization and material control of various plates were mainly determined by physical tests in a long time, which would cost much manpower, material resource and time. If computer simulation technology and forecasting techniques can be used, the process will be adjusted and optimized promptly. However, such research has not been reported at home or abroad.Therefore, base on the full use of previous work, an independent intellectual property method and system about laser welding simulation and material control was explored and established for deep drawing steels and other commonly used laser welded steels with the committal of National Science Foundation and mold technology innovation team of Jiangsu University..Main research content and innovation:(1)The transient temperature distributions of laser welded steels were simulated by means of the finite element software ANSYS based on analysis of laser welding technology and materials, then the weld and heat affected zone(HAZ) shapes prediction models were founded.Additionally, the first and last nodes control method was used in the process of heat loading in order to make sure all nodes could be selected.Thereby, the accuracy of each model’s prediction which is more than 92% can be ensured.(2) Commonly laser welded steels were studied, and the influence of composition of base metal,laser power, welding speed, laser spot, and defocusing amount to the weld and heat HAZ grain size was considered, then three most important factors were found according to weights. So the corresponding optimal process plans can be gained. Grain size prediction models were put forward. Application results showed that the forecasting accuracy of grain size in weld and HAZ were above 95%.Therefore, the proposed models are reasonable and applicable.(3)Based on the above findings, a numerical simulation of laser welding and material control system was designed by means of Partial Least-Squares Regression. A large number of applications proved that the system has an outstanding general applicability in weld and HAZ shape, grain size, and mechanical properties.What’s more, this system can be applied to laser welding applications areas about new and super-toughening materials. The predicted results will help technicians to improve existing production processes, and provide reliable bases for the final performance improvement of new and super-toughening materials LTWB.