Research On Simulation Of Grinding And Polishing Process For Blade Abrasive Belt

As the key component of steam turbine, blade is frequently subjected to largeload under high temperature and high pressure. In order to meet the needs of practicalengineering, the profile accuracy and surface quality of blades have stringentrequirements. The abrasive belt grinding and polishing process can ensure theprecision of the blade profile and the high surface quality, and improve the efficient ofblade machining. The application of the abrasive belt grinding and polishing processsimulation technology, not only can predict the abrasive belt grinding and polishingprocess, but also can clear the experimental direction and optimize the processparameters.Based on new hybrid grinding and polishing machine, this article researches onthe abrasive belt grinding and polishing mechanism, the normal force forecast and theparameters optimization of grinding and polishing, which combined with the keyprogram of National Natural Science Foundation of China “New theory andtechnology of grinding polishing and measuring on blade complex surface”. Finallythe more precise processing simulation and the optimum parameters of the abrasivebelt grinding and polishing for the machine are obtained.A model of abrasive belt grinding grain is built, and it is applied to establish thetheory models of single abrasive grinding thickness and grinding force. With theanalysis of the temperature field on blade in the process of abrasive belt grinding andpolishing, the numerical relationship between different temperatures is clear. Theabrasive belt grinding and polishing mechanism is researched through the mathematical model based on the grinding and polishing mechanism of singleabrasive.The plastic finite element method is adopted to simulate the grinding andpolishing process of single abrasive. The pre-processor of simulation is determinedaccording to the blade grinding and polishing characteristics, then the single graingrinding and polishing mechanism that effected by temperature and time factor isresearched. The grinding and polishing process with different grinding and polishingparameters is simulated to predict the grinding and polishing force and thetemperature change curve. The force and the temperature influence law of the singlegrain grinding and polishing performance with each grinding and polishing parameteris obtained.The evaluation function model is constructed by the surface roughness andmaterial removal rate mathematics of grinding and polishing. The evaluation functionis optimized with the application of particle swarm algorithm and the belt andworkpiece speed which satisfies the small surface roughness and large materialremoval rate is iterated out. Force calculation model of abrasive belt grinding andpolishing on the basis of single abrasive calculation model is set up, then the mainfactors influencing the abrasive belt grinding and polishing normal force is clear.Based on the new hybrid grinding and polishing machine, abrasive belt grindingand polishing force and grinding temperature measurement system are constructed.Through the single factor experiment, the influence law of the abrasive belt grindingand polishing force and the workpiece surface temperature is obtained, and whoseregular consistency verifies the correctness of the simulation. Through the orthogonalexperiment, the coefficient of empirical formula is modified by multiple linearregression method to verify the significance of regression equation. Finally, a newempirical formula for the new hybrid grinding and polishing machine is establishedand the optimum parameters for constant pressure grinding and polishing tool systemare obtained.