Theory And Experimental Study On Cutting Depth Of 45 Steel With Pre-mixed Abrasive Water Jet

According to the positive correlation between the abrasive kinetic energy of premixed abrasive water jet and the cutting depth,the influence of cutting parameters on the cutting depth was characterized by analyzing the influence of cutting parameters on the abrasive kinetic energy.Then the numerical simulation was carried out on the pre-mixed abrasive water jet cutting 45 steel using the Smoothed Particle Hydrodynamics(SPH)and the Finite Element Method(FEM)coupling model by the LS-Dyna simulation software,which validated the reliability of the theoretical analysis and laid the foundation for the cutting test.Based on the mutual verification of theory and simulation,the experiment of pre-mixed abrasive water jet cutting 45 steel was carried out,and the accuracy of theoretical analysis and simulation was verified by the experimental results.For the data obtained from the test,the nonlinear regression algorithm was used to establish the prediction model of cutting depth,and the influence law of cutting parameters on cutting depth was further verified from the size of weight coefficient of cutting parameters.The specific content is as follows:1.Calculate the velocity of abrasive in high pressure hose,nozzle and jet beam;The abrasive mass flow rate was calculated by the abrasive mass fraction and jet flow rate.Then the cutting time is calculated according to the cutting speed and cutting displacement.Finally,according to the calculation results,the calculation formula of abrasive kinetic energy is deduced.Since there is a positive correlation between abrasive kinetic energy and cutting depth,the influence law of cutting parameters on cutting depth is characterized by analyzing the relationship between cutting parameters and abrasive kinetic energy.2.For the results of theoretical analysis,if the cutting test is directly verified,it is not necessarily accurate to grasp the direction of the test,so the simulation using LS-DYNA software,can determine the direction of the cutting test,but also check the reliability of the theoretical analysis;The contact algorithm in LS-DYNA software was used to establish SPH and FEM coupling model,particle calculation was carried out on the test material of No.45 steel and its physical properties were edited.The process of cutting No.45 steel with pre-mixed abrasive water jet was studied from the perspective of simulation,and the influence law of cutting parameters on cutting depth was explored,which laid a foundation for cutting test.3.With the simulation parameters and results as guidance,the pre-mixed abrasive water jet cutting test of No.45 steel was carried out.The selected test parameters were as follows:cutting pressure 5 groups,nozzle outlet diameter 3 groups,cutting target distance 3 groups,cutting speed 6 groups,and an orthogonal test group was established for the test;The experimental data were analyzed by means of control variables.Finally,the influence rule of cutting parameters on cutting depth was determined according to the average change rate.4.The cutting depth prediction model was established by nonlinear regression algorithm based on the data obtained from the test.Firstly,the first order linear regression algorithm was used to determine the influence order of cutting parameters.Then the fifth-order nonlinear regression algorithm is used to determine the influence weight of the combined cutting parameters.Finally,the fifth-order nonlinear regression prediction equation is established on this basis.In summary,it is found that the nozzle outlet diameter and cutting pressure are positively correlated with cutting depth.The cutting target distance and cutting speed are negatively correlated with cutting depth.The order of influence of cutting parameters on cutting depth is as follows:nozzle outlet diameter,cutting pressure,cutting target distance and cutting speed;The theoretical calculation formula of abrasive kinetic energy can provide some guidance for the derivation of the empirical calculation formula of cutting depth of pre-mixed abrasive water jet.The simulation can explore the influence law of cutting parameters on cutting depth in advance to a certain extent and provide corresponding guidance for parameter setting in the experiment.The fifth-order nonlinear regression prediction equation derived from the test data can accurately calculate the cutting depth in advance for the pre-mixed abrasive water jet cutting of No.45 steel and guide the setting of cutting parameters.The theoretical and experimental research on cutting depth of 45 steel with pre-mixed abrasive water jet has a certain guiding significance for theoretical analysis of cutting depth and practical cutting process.Figure[28]Table[36]Reference[93]...