To Analysis Surface Crack Of Support Plate Base By Using S-FEM

Gas turbine is a efficient power equipment,and it combines a number of academic disciplines engineering technology.Gas turbine is a measure of the level of national science and technology,national defense capabilities and even an important symbol of overall national strength which has a very prominent strategic position.Technology of producing gas turbine has a prominent role to improve the utilization of resources,to achieve energy conservation,to being a safety and security and promoting sustainable development.Due to it has high technical requirement,and it is made by many parts and always worked in bad environment.So it is usually short-lived and requires high reliability of the product.Rotationally symmetric support plate base is one of important components of gas turbine.Their working conditions including the support of all shafting,withstand high temperature and pressure of the turbine segment and withstand high-speed rotating rotor and nonlinear oil film force.Clearly the gas turbine shaft is an important part of the power equipment.Therefore the stability of shafting working is directly impact on the level of efficiency of the power equipment.The docking station is subject to high temperature,high pressure and high-speed impact and support of all rotating parts of the rotor and blades which including the rack,base stress concentration.So Stress concentration zone is likely produce small crack.With the crack propagation may occur machines Block failure,which directly affect the stability of the gas turbine shaft work.The size of components of gas turbine is great,and the structure of gas turbine is very complex.So it is difficult to test the fatigue properties and structural strength changes by making experiments,and the experimental cost is also high.To solve this problem,in this paper using the finite element mesh superposition method element and introducing surface crack at the location of stress concentration to analysis the three modes of stress intensity factor in expanding the changes of crack depth from the following aspects:1)To establish the global mesh of the gas turbine by using the finite element software FAST.Under the Linux operate system,the finite element before and after processing software FAST was used to modeling 1/6 of the bearing plate base,and in accordance with the actual work situation the appropriate boundary conditions was loaded to ensure the authenticity of the calculation results.2)To establish the local mesh which has surface crack by using the finite element software FAST.The local model with a surface crack was established in the FAST,and the appropriate boundary conditions and vccm boundary conditions were loaded at the local mesh.The stress concentration area of the overall model was found by using ANSYS,and the crack was implanted in the location of stressconcentration which may occur crack.3)To analysis surface crack of gas turbine by using S-FEM software.Local model with a surface crack was implanted into the global mesh in the location of most centralized stress.The S-FEM was used for numerical simulation about the gas turbine,and then the overall model and partial models of stress changes and strain diagram were viewed through the post-processing software FAST.4)To view the change of the stress intensity factor under the three modes.The growth of surface crack was simulated by implanting growing depth crack,and the stress intensity factors about the three modes were obtained.The trend of surface crack propagation was predicted by observing the curve of the stress intensity factor.