Optimization Of Isothermal Extrusion Energy Consumption Based On PSO

The extrusion process is widely used in various industries due to its high material utilization rate and good product quality.However,the setting of extrusion process parameters mainly depends on product quality,resulting in high consumption and low efficiency.As the aluminum profile industry enters the era of overcapacity,achieving coordinated control of energy cost and quality has become an urgent problem.Since the product quality changes with the parameters during the extrusion process,it cannot be effectively guaranteed.But the isothermal extrusion process can effectively ensure the quality of the profile by maintaining a constant temperature at the exit surface of the profile.Therefore,isothermal extrusion has attracted more and more scholars' attention,but there are still few studies on its energy consumption.For the optimization of isothermal extrusion energy consumption,this thesis first established a model of extrusion energy consumption based on the upper bound theory combined with the isothermal extrusion mechanism.Secondly,combined with numerical simulation technology,a finite element analysis model was established to analyze the influence of process parameters on the extrusion energy consumption and the temperature change and distribution of the profile exit surface;Finally,the support vector machine was used to establish the prediction model of the process parameters and the isothermal extrusion energy consumption and the profile exit surface temperature.The optimization parameters of process parameters and isothermal extrusion energy and profile outlet surface temperature were optimized by particle swarm optimization to achieve the best profile quality and minimum forming energy consumption.The specific research works are as follows:(1)In view of the current lack of calculation method of isothermal extrusion forming energy consumption,this thesis analyzed the metal flow characteristics of the extrusion process,and divided the extrusion process into three stages.Based on the characteristics of each stage and the upper bound theory,an energy consumption calculation model was established.The energy consumption model shows that the isothermal extrusion forming energy consumption is directly related to the extrusion speed and metal deformation resistance.(2)Aiming at the problem that some parameters in the energy consumption model cannot be directly obtained,this thesis selected the initial temperature of the billet,the temperature gradient of the billet and the extrusion speed as the research object according to the established energy consumption model.The finite element analysis model of the hollow circular tube was established by numerical simulation software.By simulating the isothermal extrusion process under different process parameters,the simulation results were analyzed,and the effects of process parameters such as initial temperature of billet,temperature difference between first and last billet and extrusion speed on extrusion energy consumption and temperature change and temperature distribution of profile exit surface were studied.(3)Aiming at the difficult problem of reasonable selection of extrusion process parameters,this thesis used support vector machine to establish the prediction model of process parameters and profile quality and extrusion molding energy consumption.Based on this,the process parameters and extrusion molding energy consumption and profile quality were established.The multi-objective optimization model was solved by particle swarm optimization algorithm to optimize the extrusion process parameters.(4)Based on the models and methods established above,this thesis used the MATLAB simulation platform to establish a “extrusion energy simulation optimization system” to provide theoretical support and technical reference for energy optimization of extrusion.