Research Of The Three-dimension Contact Problem Of The Steam Turbine Blade's Root And Groove By The Distorted Model

The blades of the steam turbine work at the high-temperature and high-pressure steam medium. Because of the high speed, the blades make centrifugal effect. The credibility joint between the blade root and groove is the key which relations the safe work of the steam turbine. The balde root and groove joins by the tooth, that is more advanced joint manner now. For optimizing the design of tooth, we must analyse the contact stress between the blade root and groove. The is three-dimension contact problem, numerical value method and experiment analysis method is the main method for them because of the complex structure and inexistencing resolve result. The three-dimension frost slice-up method is more mature method for the three-dimension contact problem.Because of the section along the centre line of the blade root and groove is changeless, this paper applies the distorted model, so we advantage the manufacture and machining because of minishing its thickness, meanwhile we save the resource, shorten the cycle, and avoid the big distortion of the model under the high temperature. But it is difficult to abtain the similarity by the similarity theory for the distorted model of the blade's root and groove, so in this paper we put forward the FEM to analyse the similarity, and we analyse the factors which influence the contact stress by the FEM.In this paper we emphases on the contact analysis of blade's root and groove distorted model by the FEM. First we summarize the basic theory about FEM and contact analysis. Then we analyse its contact problem, summarize the main factors which influence the contact stress. In the paper the main factors include model thickness, Young's modulus, friction coefficient and initial gap.In this paper another work is to study the application of the digital light-elastic method in the three-dimension frost slice. we abtain the full-court isoclinal line and * by six images, by the number-addition method for the arithmetical we can find the stress concentrated area visually, and we don't need increase load.