Fatigue Process Simulation Of Turbine Rotor Material 30Cr2MoV And Damage Assessment Method

Turbine rotor is one of the core components in turbine unit, whose working environment is poor, bulky, costly. In working conditions, the load fluctuations, temperature gradient, stress concentration and many other factors make the rotor produce a certain amount of plastic deformation, bearing the cycle of plastic strain, led to destruction and accident. Therefore, the evaluation of the rotor life is particularly important. Energy theory method is now very hot in metal fatigue damage research, which is very adaptable for the high-temperature components' low-fatigue and creep coupling problem, has a very good development prospect. On the other hand, with the development of numerical method, the finite element theory, computer science and other fields, finite element analysis software can simulate the rotor cycle process and replace the traditional material fatigue test. The application of simulation technology can not only reduce the number of experimental prototype, reducing costs, but also get more experimental data which cannot attain in traditional test, has now become the development direction of fatigue damage evaluation.This thesis takes large thermal power plant turbine rotor as the research target, based on the study of rotor steel 30Cr2MoV static mechanics and fatigue test data, programming material elastoplastic constitutive relations in subroutine using Fortran language and incremental finite element method, considered damage mechanics modeling as well. Then establishing 3-D standard sample model for fatigue test on Msc.Marc platform and simulating the cycle loading process. Through simulation, attained stress and strain distribution, circulation course of the stress-strain curves (hysteresis loop). verify the fatigue experimental results in elastic and elastic-plastic stage and found that experimental data and results were matched well. Then study the change rule of plastic energy. Compared the simulation results to experimental data, found that the two have many similarities. confirmed that virtual experiments method is effective.This article summed up general numerical simulation method of fatigue damage process , which target was standard fatigue specimen. Attained specific requirements of the fatigue damage simulation, such as grid unit type, grid number, storage space, iterative step etc, the method is fast and accurate. Established rotor material fatigue life assessment method through finite element technology based on the "mechanics - injury" coupling analysis,and preliminary study energy phenomena of the fatigue process.