Optimization Of Low Pressure Casting And Hot Forming Process Parameters For Aerospace Components

When facing practical engineering problems,optimizing processing parameters can effectively improve product quality and shorten production cycles.Therefore,how to quickly and accurately obtain the optimal process parameters is the focus and difficulty of current research on parameter optimization.The purpose of the thesis is to research two typical hot working processes,low pressure casting and hot forming,involved in the design and development of a key aerospace component.In order to further improve the efficiency of hot working process optimization,the thesis uses surrogate model optimization technology to construct a non-mapping relationship between process parameters and forming results,and combines optimization algorithms to achieve rapid solution of the optimal process parameters.At the same time,the thesis has also conducted secondary development of relevant finite element software,built a thermal processing simulation optimization platform using MATLAB software,and packaged it as an optimization platform software.The main research contents are as follows:(1)Based on the finite element analysis method,the finite element software Pro CAST and ABAQUS were respectively used to establish thermal-mechanical coupling simulation models for ZL114 A thin-walled cylindrical tank low-pressure casting and B410 LA thin plate hot forming.A detailed analysis was conducted on the filling process,solidification process,and predicted distribution of shrinkage defects in the low pressure casting of the cabin casting.The forming process of the thin plate was analyzed,and the rationality of the hot forming process of the thin plate being approximately a quasi-static process was verified through energy analysis.The influence factors of two kinds of hot working defects were analyzed by orthogonal test,and the parameters to be optimized were determined.(2)Combining adaptive surrogate models with intelligent algorithms can improve Kriging model fitting accuracy and algorithm optimization efficiency.Based on the adaptive Kriging model,the process parameters of low-pressure casting and hot forming were optimized.After determining the optimization parameters and objectives,then use Latin hypercube sampling to select an initial sample set,obtain corresponding response values through finite element simulation,build a Kriging model,and finally quickly obtain the optimal process parameters through optimization algorithms.The results show that the optimal process parameters obtained by the surrogate model significantly reduce the shrinkage volume of the cabin casting and the maximum thinning rate of the thin plate.(3)According to the development requirements,build a simulation and optimization platform for hot working processes such as low-pressure casting and hot forming.The platform is mainly divided into three modules: hot working finite element simulation module,hot working process optimization module and knowledge database module;the hot working simulation optimization platform can realize the hot working process optimization function oriented to hot working process integration simulation,calculation and optimization method based on surrogate model.The knowledge database serves as the data repository and prior data extraction library.Finally,through the App Designer toolbox,a user visual interface with simple layout and convenient operation is developed and packaged as an independent software with clear function division and simple operation,the optimization operation of surrogate model is simplified and the optimization efficiency is improved.