Research And Numerical Simulation Of Laser Arc Hybrid Welding Process For AH36 Sheet

With the trend of ship lightweight,marine steel sheet is more and more widely used.At present,the most commonly used connection method for steel plate is welding.Laser arc hybrid welding is a widely used welding method,which has significant advantages.Compared with the traditional welding method,laser arc hybrid welding has the advantages of fast welding speed,single side welding,double-sided forming,small welding defects and so on.In the pursuit of intelligent and efficient future manufacturing industry,it is of great significance to study the specific process.In this thesis,the numerical simulation of laser arc hybrid welding process of 6 mm thick AH36 steel plate is carried out.The classical double ellipsoid heat source model and rotating Guass body heat source model are used to simulate the arc and laser respectively.The temperature field in the process of hybrid welding is simulated by APDL written by finite element software ANSYS,and the temperature field at each moment in the process of welding simulation is analyzed Thermal cycle curve of different node time history and temperature map of weld center path;The materials used in the actual test and the laser arc hybrid welding system developed and assembled by ourselves are introduced,including laser,welding machine,wire feeder,water cooler,robot arm and welding platform.The test methods and relevant industry regulations used in welding test and inspection test are described;The laser arc hybrid welding experiment was carried out by using the self built welding system.The influence of laser power,wire feeding speed,welding speed,wire spacing and other welding parameters on the welding quality,weld penetration and weld width was studied by using the method of control variables.The variation law and internal mechanism were analyzed,and the best test parameters were optimized;Mechanical test and metallographic test are carried out for the welded plate under the optimal process parameters,which proves that it meets the industry standard of welded plate;The drilling method is used to measure the welding stress,and the sum of the maximum transverse stress and longitudinal stress is taken as the welding stress to analyze.The control variable method is used to study the influence of laser power,wire feeding speed and welding speed on the welding deformation and welding stress of composite welding and its internal mechanism;At the same time,single arc welding and compound welding are carried out on the same plate under the same constraint conditions,and a comparison is made between them.It is proved that compound welding has smaller welding deformation than traditional welding.The research of this paper can provide some reference for the application of laser arc hybrid welding in marine sheet metal,and the self-assembled welding laboratory can help the intellectualization of laser arc hybrid welding system.