Analysis And Optimization Design Of Structural Characteristics Of Stepper Mechanism Of Pipe Hydrostatic Tester

The rapid development of the energy industry causes pipeline transportation and steel industry’s boom·At the same time, Steel product’s quality and reliability of the use of security has increasingly become the people’s central issue. Pipe hydrostatic tester is developed based on this background, a balance control on the use of water pipe for hydrostatic testing unit. Thus, its performance will directly affect the accuracy of the steel’s experiment. Stepper mechanism as a single machine, only contacting on steel for a long time, and interacting with three else mechanism, achieves steel’s going down, clamping, going up and movement. The level of its structural strength and stiffness and structural design have a serious impact on pipe hydrostatic tester’s performance.In order to solving the problems of stepper mechanism of pipe hydrostatic tester in strength, stiffness and structural design, in this paper, on the basis of previous studies, and fracture mechanics, fatigue theory, elastic-plastic theory and optimal design, making use of three-dimensional modeling software Pro/e and finite element analysis software ANSYS, welding of structural defects failure assessment analysis and stability analysis are carried out in stepper mechanism of pipe hydrostatic tester from a design point of view, and under the permission of strength and stiffness, the main load-bearing parts——frame of the stepper mechanism is designed by topology optimization. Specific work and conclusions are as follows:1、By carrying out the failure assessment analysis of the welded structure of stepper mechanism of pipe hydrostatic tester, a reasonable and effective evaluation method is found. By comparing the engineering instance with experiment, we can get that the error is reasonable in the design. This condition can be guaranteed to meet the Welded structure strength requirements.2、By carrying out the non-linear buckling analysis of Frame of the welded structure of stepper mechanism of pipe hydrostatic tester, buckling loads is found under steel’s going down, clamping and going up. By comparing of buckling loads under four conditions, Finding that the loads should be less than0.542e8N, when the frame don’t occur instability. This condition can be guaranteed to meet the Welded structure stiffness requirements.3、By carrying out the non-linear static analysis of Frame of the welded structure of stepper mechanism of pipe hydrostatic tester before its optimization, the maximum stress and the maximum Deformation are found when external loads have an effect on the body. Both stress and deformation meet the design requirements.4、By carrying out the Topology Optimization that will reduce30%weight of Frame of the welded structure of stepper mechanism of pipe hydrostatic tester, Finding that Excess body weight mainly is on both sides of frame, U-shaped support frame body and the U-shaped baffle plate.5、By carrying out the non-linear static analysis of Frame of the welded structure of stepper mechanism of pipe hydrostatic tester after its optimization, the maximum stress and the maximum Deformation are found when external loads have an effect on the body. Both stress and deformation meet the design requirements.