Finite Element Analysis Of The Booster On The High Pressure Water Jet Cutting Equipment

As an emerging technology,ultra high pressure water jet technology has been widely used in various industrial fields during nearly 30 years.Booster,which is a core member,play a important role on the performance of the high pressure water jet equipment.There is a big gap of research performance between external and home.Due to technical reasons of confidentiality in foreign,few information published.learn from Domestic and foreign enterprises that CAE technology has been fully adopted to new product development of booster.Urgent to apply CAE technology into improving the development of new products.In this paper,study for a booster on the high pressure water jet cutting equipment of a companies,using the finite element analysis technology on the stress analysis and fatigue life analysis of the booster between 400 MPa and 600 MPa.The main work and achievements are as below:(1)Described the hydraulic principles of high pressure water jet equipment and works of the booster,obtained the stress distribution of high-pressure cylinder barrel,introduced the high-pressure vessel autofrettage;discussed the selection principle of using finite element analysis software and determined the technical route of finite element analysis on booster;(2)Applied self-reinforcing finite element analysis on the blockage and the high pressure cylinder,on this basis,established the 400 MPa turbocharger assembly finite element model.Carried the finite element analysis on the 400 MPa booster,acquire the maximum stress were 532.864 MPa and 545.367 MPa on the conditions of 380 MPa and 400 MPa working pressures.The results show that the maximum stress appears at the inner side of joints between high-pressure cylinder and cylinder head and the wall thickness of 1 / 4-1 / 3 area on high-pressure cylinder,under long-term cyclic loading cycle,those areas prone to fatigue failure;high stress value on the end cover and cylinder head screw joints,occlusion phenomenon could be occurred;the maximum stress values of blockage were found in the air vent at the junction,because of the concentration of stress,this area trend to fatigue failure.These phenomenas agree with the results of enterprise existing performance test experiments.(3)Used MSC.Fatigue analysis of the Fatigue life of 400 MPa booster,acquired the fatigue life analysis of the booster is8.83×106cycles under 380 MPa working pressure,that is to say normal working time is 2453 hours;6.4 × 106 cycles under 400 MPa and 1775 hours.Those data agree with enterprise actual operation situation,reach to the 400 MPa booster actual working life demands.(4)Modeling the turbocharger finite element model of 600 MPa,compared with the stress results of booster working on 1080MPa?970MPa?950MPa?940MPa?920MPa?900MPa conditions,determined the optimum autofrettage pressure is about 970 MPa,agreed with the pressure 970 MPa acquired from theoretical calculation.Then discussed the pre-load on the supercharger assembly,lay the foundation for finite element analysis of stress and fatigue later.(5)Carried the finite element analysis on the 600 MPa booster,acquire the maximum stress were 564.668 MPa and 554.885 MPaon the conditions of 600 MPa and 560 MPa working pressures.The results show that the maximum stress appears at the end side of joints between high-pressure cylinder and cylinder head and the wall thickness of 1 / 4-1 / 3 area on high-pressure cylinder,prone to fatigue failure.The stress of screw and nut not reached the yield strength of material,stay far from snap and occlusion.Neither for the end cover and cylinder head.(6)Used MSC.Fatigue analysis of the Fatigue life of 600 MPa booster,acquired the fatigue life analysis of the booster is4.46×106ycles under 380 MPa working pressure and 96000 N pre-load,normal working time is 929 hours;6.06×106cycles under 560 MPa working pressure and 90000 N pre-load,working time is 1262 hours.The results show that the new booster in design failed to reach the standard requirements which is normal working time up to 1500 hours.In order to solve this problem,two kinds of improvement measures,replace the materials of high pressure cylinder and adjust the structure of high pressure cylinder,are proposed to enterprises or reference.It is reliable that finite element analysis technique applied in high pressure vessel performance analysis,according to compared the analysis result of stress and fatigue and test of 400 MPa booster,and proved that CAE technology can be a essential mean for booster development.Except that,verified the effectiveness of the new development of 600 MPa booster,reduced the investment risk for the enterprise.