Structural Reliability Analysis And Optimization Design Of T2120 Deep Hole Drilling And Boring Machine Bed

The machine tool bed is an important part of the deep hole machine tool.The reliability of the structure and its own quality have great influence on the overall performance of the machine tool.The structural components of most deep-hole machining tools often use more conservative experience in designing,which results in redundant and cumbersome structural components.At the same time,the traditional experience design does not consider the influence of the randomness of the structural design parameters on the structural response.In this paper,the T2120 deep-hole drilling boring machine bed is used as research and application object.Finite element method,Monte Carlo method and response surface method are used to perform finite element dynamic and static analysis,reliability analysis and sensitivity analysis,and bed respectively.The lightweight design of the body structure.The study includes the following points:(1)This paper builds a finite element model of machine tool bed based on parameterized command flow written in APDL language.The static analysis and modal analysis of the bed were performed in the ANSYS finite element analysis software.The stress cloud map,displacement cloud map and low-order modes of the machine bed structure and corresponding vibration-type cloud diagrams were obtained,and the bed body finite element was obtained.The calculation results are analyzed to find the disadvantages of uneven stress distribution and weak local stiffness.(2)In this paper,based on the stochastic finite element method,the structural reliability of the machine tool bed is analyzed,and the parameters that affect the bed performance are regarded as random variables that obey the normal distribution,then the limit state function of the bed failure is defined.The PDS module in ANSYS software was used to analyze thereliability of the bed structure's strength,static stiffness and dynamic stiffness respectively.Monte Carlo simulation sampling was used for simulation calculation to obtain quantifiable reliability.(3)The sensitivity analysis results are obtained in the post-processing of the ANSYS-PDS module.By analyzing the reliability of the machine tool bed strength,static stiffness and dynamic stiffness,it is obtained that the random variables have an effect on the strength of the bed at a significant level of 0.025.The order and extent of the effects of static and dynamic stiffness can provide designers with reference guidance for the optimal design of metal structures.(4)In this paper,the bed structure parameters are optimized based on response surface methodology.With the optimization platform provided by ISIGHT software,ANSYS finite element analysis software is integrated to establish the constraints of the bed's static strength reliability,maximum deformation and first order natural frequency.The mathematical model of the optimization goal is to minimize the bed body size.The optimal Latin hypercube test design method was used to generate sample data points in the design space and perform numerical simulations.A quadratic polynomial response surface approximation model was established,and a multi-island genetic algorithm was used for optimization calculation.The calculation results show that under the premise of guaranteeing the performance of the machine tool,the ideal machine bed structure size is obtained through the optimized design of the bed,the bed body mass is reduced by 11.2%,and the lightweight design of the bed structure is realized.