Research On Reliability Analysis And Prediction Model Of Mechanical Properties Of FDM 3D Formed Parts

Fused Deposition Modeling(FDM)is the most widely used technique in rapid prototyping(RP).In actual production,the reliability of mechanical properties is an important indicator for measuring 3D printed product quality.How to improve the reliability of mechanical properties of FDM 3D printing molded parts is very important.This article takes FDM 3D printing molded parts as the research object,and aims to improve the reliability of the printing parts,and conducts research from different angles.(1)This paper introduces the working principle,forming process and forming characteristics of FDM,analyzes the factors influencing the mechanical performance reliability of FDM 3D printing molded parts from three aspects of printing materials,process parameters and printing equipment,and puts forward the mechanical performance reliability analysis method of FDM 3D printing molded parts,which provides a theoretical basis for the mechanical performance reliability analysis of FDM 3D printing molded parts in this paper.(2)Compressive strength and tensile strength are two important indicators to measure the mechanical properties.In order to determine the main process parameters that affect the mechanical properties,a set of L16 orthogonal tests are designed using the Taguchi method,and the mechanical tests are performed using analysis of variance Studying the process parameters,it is preliminarily concluded that printing temperature and packing density are the main factors affecting compressive strength;packing density and layer thickness are the main factors affecting tensile strength;use mechanical experiment date,combined with mechanical properties Reliability analysis method established the reliability model of mechanical properties of FDM 3D printing molded parts,completed the reliability analysis of mechanical properties of FDM 3D printing molded parts,and achieved the purpose of improving the reliability of mechanical properties by optimizing process parameters.(3)In view of the influence of nozzle outlet speed on the reliability of mechanical properties of molded parts,this paper studies the influence of nozzle parameters on outlet speed from four main factors: convergence angle,temperature of heating block,length of rectifier section and length of nozzle aisle.Using ANSYS analysis software,the temperature nephogram and outlet speed nephogram of different nozzle parameter combinations are analyzed,and the stability of nozzle outlet speed is determined The best combination of nozzle parameters.Combined with the test and mechanical performance reliability model,it is further verified that the mechanical performance reliability of the molded parts printed with the best combination of nozzle parameters has been significantly improved.(4)In the case of determining the best combination of nozzle parameters,a GA-BP based mechanical performance reliability prediction model of FDM 3D printing molded parts is established.The printing temperature,layer thickness,filling density and filling speed are taken as input variables,and the reliability of compressive strength and tensile strength are taken as output variables.By comparing the actual and predicted values of BP neural network prediction model and GA-BP neural network prediction model,the results show that the accuracy of the mechanical performance reliability prediction model based on GA-BP neural network is significantly higher than that of BP neural network The prediction model of mechanical property reliability provides a theoretical basis for the prediction of mechanical property reliability of FDM 3D printed molded parts...