Research On Energy Efficiency Evaluation And Multi-objective Optimization Of Laser Welding Process

Laser welding technology has an extensive development and application prospect in the fields of aerospace and mechanical manufacturing,cause its advantages of small heat input,high welding efficiency and easy to realize automation.With the continuous development of the manufacturing industry,modern welding technology is required to gradually realize the development goal characterized by energy saving,high efficiency and high quality,which makes the reduction of energy consumption in welding process and the improvement of welding energy efficiency become one of the important problems to be solved in the welding field.At present,the research on laser welding mainly focuses on welding bead morphology,welding bead defects and mechanical properties,etc.,and there is little research on the energy efficiency of laser welding.Therefore,this paper combines theoretical and experimental research on laser welding energy efficiency and multi-objective optimization methods,the main work is as follows:Firstly,based on the analysis of the energy characteristics of the laser welding process,the process system of "laser and workpiece interaction" was established as the laser welding energy efficiency research system boundary.Using exergy theory to analyze the energy and materials of the laser welding process,and the energy efficiency function of laser welding was established.In addition,from the perspective of suppressing welding seam forming defects,the integrity of laser welding forming weld bead is analyzed and the welding bead integrity function is further established.Then,orthogonal test design was used to perform laser welding experiments on6061 aluminum alloy to obtain the experiment data of energy efficiency and welding bead integrity.Using the response surface method to respectively fit and build a parameterized model of laser welding energy efficiency and welding bead integrity,analyzing the influence of laser power,welding speed and defocusing process parameters on laser welding energy efficiency and welding bead integrity.Finally,a multi-objective optimization method for laser welding considering energy efficiency,welding bead integrity and welding cost was proposed.Establish a multi-objective optimization mathematical model with maximum energy efficiency,optimal welding bead integrity and minimum welding cost,then use nonlinear programming genetic algorithm to solve the model to obtain the optimal process parameter combination,and the accuracy and effectiveness of the model and method are verified through experiments.