Research On The Optimization Of Loading Path In Y-shape Tube Hydroforming Based On Fuzzy Control

Hydroforming technology is a new technology in the field of plastic processing and the tube hydroforming is one of its important branches.The formed parts have the advantages of smooth surface quality,good uniformity of wall thickness,high structural strength,strong integrity and less processing cost.In this paper,the idea of reducing the quality of parts with tubular materials,the theory of tube hydroforming and fuzzy control theory are applied to analyze the comprehensive forming law of asymmetric Y-shape tube,and the optimization of loading path is carried out according to its forming characteristics and fuzzy control theory.In the first part,a typical Y-shape tube with regular shape is taken as an example to conduct geometric and finite element modeling,and Dynaform finite element simulation software is used for numerical simulation of hydroforming.The forming law,main defects and defect location are discussed by numerical simulation.The effects of process parameters,including geometric shape parameters,friction coefficient and loading path,on the forming quality were discussed.It provides theoretical guidance and design basis for the subsequent application of fuzzy control theory to optimize the loading path of hydroforming.The main content of the second part is to optimize the loading path of Y-shape tube hydroforming through constructing the fuzzy control system model.Firstly,the theoretical basis of fuzzy control is introduced,and based on the above basic Y-shape tube hydroforming law,the idea of fuzzy control method to optimize the loading path is constructed.According to its forming characteristics,the control variables and controlled variables were selected,and then the fuzzy control logic was constructed through a small amount of trial-and-error simulation analysis,including the framework construction of Simulink control model,the determination of the range of variables,fuzzy interval division,membership function selection and fuzzy rule definition.After several iterations of the fuzzy control system and Dynaform finite element simulation,the qualified parts are finally formed.Finally,the simulation results are compared with the experimental results to verify the effectiveness of the fuzzy control system optimization.The main content of the third part is to apply the internal high-pressure forming process and the fuzzy control system to the manufacture and forming optimization of the Y-shape manifold of a vehicle exhaust system.To illustrate the hydroforming technology is widely applied in actual production and inspection the fuzzy control system built above has a common applicabilityin the actual production design value,a Y-shape manifold of vehicle exhaust system were selected as the research object,which is originallymade by twice stamping process and then welded.In this paper,as far as possible in guarantee under the constant interface position and size of structure design improvements,so that you can through the internal high pressure forming process quality qualification,complete structure parts.Under the condition that the interface position and size are fixed as far as possible,the improved structure design is carried out so that qualified and structurally complete parts can be processed by the hydroforming process.