Structural Design Of Prestressed Steel Wire Wrapped Ultra High Pressure Hydraulic Cylinder

In recent years,with the rapid development of global industrialization,The application of hydraulic press has been more and more extensive,its application fields have gradually expanded from the traditional mechanical industry to the defense industry,aerospace,nuclear industry and other fields.Meanwhile,hydraulic press show the trend of miniaturization and heavy-load,its forging speed and working precision have also improved.This put forward higher requirements for the hydraulic cylinder of the core part of hydraulic press.As the core part of the hydraulic press,the hydraulic cylinder directly determines the bearing capacity,working precision and forging speed of the hydraulic press,it has show the trend of ultrahigh pressure and small size because of miniaturization and heavy-load of the hydraulic press.Obviously,the traditional design method of hydraulic cylinder is unable to meet the requirements.Prestressed steel wire wound hydraulic cylinder has already become the best choice for the manufacture of ultrahigh pressure hydraulic cylinder,which has the advantages of high pressure,high fatigue life,small size,good safety performance.At present,a lot of achievements have been made in the study of the prestressed steel wire wound hydraulic cylinder.However,the steel wire layers are simplified to equivalent external pressure and the friction between the layers are not considered in the course of the study,it is difficult to accurately reflect the stress and strain of the inner cylinder and the steel wire layer.The influence of the number of steel wires on the wound cylinder has not been researched in the process of winding.Consequently,the 80MPa ultrahigh pressure hydraulic cylinder is designed by the prestressed wire winding technology.The friction between the layers are considered and pressures are exerted by every layer in the process of analysis using ANSYS.The steel wires is divided into ten layers,five layers and two layers,and the influence of the number of steel wires on the wound cylinder is researched The results show that the stress and strain of the inner cylinder and the steel wire layer can be accurately reflected.The main contents fall into such parts as follows:In the first place,the structure,working principles,advantages and design principles of prestressed steel wire wound hydraulic cylinder have been introduced.The relative calculation formula is deduced according to the knowledge of elastic-plastic mechanics.The size of the 80MPa wound cylinder is calculated.The winding process is divided into five layers,then the initial tension exerted on each layer and the stress distribution of the inner wall of inner cylinder in the winding process are obtained.Then the finite element model of 80MPa ultrahigh pressure hydraulic cylinder is created by using ANSYS program’s APDL,which is used to simulate the process of the prestressed steel wire winding and the working status of wound cylinder.The winding process is also divided into five layers,then the stress distribution of the inner cylinder and steel wire layer in the winding process is obtained,the tangential stress and radial shrinkage of the inner wall of the cylinder are also given.The stress distribution is analyzed in detail in the working status of wound cylinder.The steel wires is divided into ten layers and two layers,and the influence of the number of steel wires on the wound cylinder is researched.The results show that the FEM results are consistent with the theoretical values,and they all meet design principles of prestressed steel wire wound hydraulic cylinder.The more the number of steel wires,the better the pre-tighten purpose.The value of finite element simulation is closer to the theoretical value.In the end,the technological requirements of 80MPa ultrahigh pressure hydraulic cylinder is introduced and hydraulic cylinder is winded.The winding process is also divided into five layers,the strain on the inner wall of the cylinder is tested in the winding process,the tangential stress of the inner wall is obtained.The radial shrinkage of the inner wall of the cylinder is measured.The test results are compared with the theoretical calculation values and the FEM results.Research results show that they have similar values.The test of wound cylinder is carried out to verify the correctness and reliability of the simulation analysis and theoretical analysis.This paper adopts prestressed wire winding technology to design 80MPa ultrahigh pressure hydraulic cylinder.The size of hydraulic cylinder is decreased obviously and the the production cost is also reduced significantly.It has an important practical significance for the design of ultrahigh pressure containers.