| The machine tool needs to have better static,better dynamic performance,better thermal performance,thermal-force coupling performance and lightweight,with the continuous development of the modern machinery manufacturing industry.Basalt fiber reinforced polymer concrete(abbreviated as BFPC)is a new composite material based on basalt fiber as the reinforcing phase and resin polymer concrete as its matrix,which has advantages of high damping,high specific heat capacity and low thermal conductivity.Therefore,the use of BFPC materials to manufacture the basic parts of the machine tool must be able to effectively improve the comprehensive performance of the machine tool basic parts,and even improve the comprehensive performance of the machine tool.Make machine tools meet the development needs of modern machinery manufacturing.This article relies on the National Natural Science Foundation of China "Basic Theory and Key Technology Research of Basalt Fiber Reinforced Concrete Machine Tool(51375219)".Based on the previous study of the research group,first of all,based on the damping properties of the material,the group allocation ratio of BFPC is optimized.Then,taking the gantry frame assembly of a certain CNC machining center as the prototype,the structural design,optimization,and performance analysis of BFPC machine tool basic part are studied.The main research content of this paper is as follows:(1)A neural network prediction model of BFPC damping ratio is established by comprehensively using experimental research and neural network theory.The variation between BFPC damping ratio and basalt aggregate content,fly ash filler content,epoxy resin content and basalt fiber content is studied.Based on the established neural network prediction model,a MATLAB optimization program for the BFPC damping ratio is developed,and then the group allocation ratio of the BFPC damping ratio is optimized.The main performance parameters such as the optimal damping ratio,compressive strength,elastic modulus and Poisson's ratio of BFPC are measured through experiments.(2)Taking the gantry frame components of a certain type of CNC gantry machining center as a research prototype.Typical working conditions and process parameters of the machine tool are determined.Then the cutting force of the machine tool is calculated by theoretical analysis.The force load and moment load of the gantry frame assembly is also calculated.(3)The finite element simulation analysis method is used to study the static and dynamic characteristics of the prototype gantry frame assembly.The analysis results lay the foundation for the design and optimization of the BFPC gantry frame assembly.(4)The three-dimensional model of BFPC required for topology optimization is initially designed based on the structural relationship and dimensions of the prototype gantry frame components.The static analysis results of the prototype structure are taken as the constraints.The lowest quality and the highest of first three modal frequencies are taken as the objective function.BFPC gantry frame components are optimized by topology.The BFPC gantry frame assembly suitable for manufacturing is designed based on topology optimization results,and the design parameters that affect its comprehensive performance are initially set.(5)The key design parameters that affect the comprehensive performance of BFPC gantry frame components were screened out by orthogonal experiment,parametric design and finite element simulation analysis.The response surface analysis method is used to quantitatively analyze the influence of the key design variables on the comprehensive performance of the BFPC gantry frame components.(6)The key design parameters are selected as design variables.The maximum static deformation and the maximum static stress of the BFPC gantry frame assembly are not greater than the corresponding performance of the prototype structure as a constraint.The BFPC gantry frame assembly has the smallest mass,the highest first-order natural frequency,and the minimum amplitude of the center of the saddle guide along the three coordinate directions is the optimization goal.The objective function for multi-objective parameter optimization of the BFPC gantry frame assembly is that the BFPC gantry frame assembly has the smallest mass,the highest first-order natural frequency and the lowest amplitude in the three coordinate directions at the center of the saddle guide.The quality,static and dynamic performance of the optimized BFPC gantry frame components and prototype gantry frame components is compared and analyzed to demonstrate the superiority of the BFPC gantry frame components.(7)The main heat sources affecting the thermal performance of the machine tool are analyzed,and the heat flux of each major heat source is obtained through theoretical analysis.The thermal performance and thermal-force coupling performance of the two kinds of gantry frame components were studied using a finite element simulation analysis method.Comparing and analyzing the results,it proves that the BFPC gantry frame components have better thermal insulation performance and resistance to thermal deformation.And it also proves the effectiveness of the BFPC gantry frame components for improving the thermal stability of the machine tool and even improving the machining accuracy of the machine tool.The research results of this paper provide a theoretical basis for the application of BFPC new materials to machine tool basic parts to improve the level of machine tools and even mechanical manufacturing.The paper has 115 figures,22 tables,and 143 references. |
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