Study on finite element method of thermal stress of turbine blade under large deformation
Focusing on the finite element method for simulating the large deformation of turbine blade under varied loads,a method for calculating the thermal stress coupled with geometric nonlinearity was proposed based on the eight-node hexahedron element.B-bar and hybrid element technologies were used to improve the precision of results;the updated-Lagrangian(UL)incremental approach was presented for the simulation of large deformation,and the Newton-Raphson iterative method was utilized to numerically calculate the thermal stress of turbine blade.Compared with ABAQUS,the relative accuracy of thermal stress and large deformation models reached 99％through examples of notched plate,cube,cantilever beam,and ring;finally,the influence of considering large deformation on thermal stress was discussed.Under temperature,aerodynamic,and centrifugal load conditions,the radial deformation of turbine blades and thermal stress decreased,and relative calculation accuracy improved by 4.67％.This research is of great benefit to the design of radial clearance and assessment of low cycle fatigue life of turbine blade,and furthermore it can provide theoretical and computational support for exquisite design of aeroengine components.
turbine bladelarge deformationthermal stressgeometrically nonlinearfinite element algorithm
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