A displacement superposition method based on the principle of compatibility of deformation is approached for solving multi contact problems.The formulas derived in this paper has been programmed to solve the load dist...A displacement superposition method based on the principle of compatibility of deformation is approached for solving multi contact problems.The formulas derived in this paper has been programmed to solve the load distribution between the teeth of a turbine disk lugs in association with FEM program,and then the maximum stress at each fillet of tooth is calculated.A study on fracture mechanics of the disk lug with different cracks in the tooth fillet is also presented.The results are in satisfactory agreement with data of the photoelastical experiments.展开更多
A lot of cracked failures of fir-tree serration accurred in the second stage turbine disc of a large numbers of certain types aeroengines in service.The characte of these cracks belongs to mechanical fatigue.In order ...A lot of cracked failures of fir-tree serration accurred in the second stage turbine disc of a large numbers of certain types aeroengines in service.The characte of these cracks belongs to mechanical fatigue.In order to find out the cause for the cracked failure,the vibrating stresses of the second stage turbine blades on test bench and their vibrating strains in flight tests have been measured in the conditions of high temperature and high rotational speed.The measured data indicate that several resonance zones really exist in the second stage turbine blades of type A and B engines.Some methods for elimination of the cracked failures of fir-tree serration in the turbine disc are provided.According to the experiece in service,a modification of type B engine hase eliminated the cracked failures of fir-tree serration of turbine disc in its service life.展开更多
文摘A displacement superposition method based on the principle of compatibility of deformation is approached for solving multi contact problems.The formulas derived in this paper has been programmed to solve the load distribution between the teeth of a turbine disk lugs in association with FEM program,and then the maximum stress at each fillet of tooth is calculated.A study on fracture mechanics of the disk lug with different cracks in the tooth fillet is also presented.The results are in satisfactory agreement with data of the photoelastical experiments.
文摘A lot of cracked failures of fir-tree serration accurred in the second stage turbine disc of a large numbers of certain types aeroengines in service.The characte of these cracks belongs to mechanical fatigue.In order to find out the cause for the cracked failure,the vibrating stresses of the second stage turbine blades on test bench and their vibrating strains in flight tests have been measured in the conditions of high temperature and high rotational speed.The measured data indicate that several resonance zones really exist in the second stage turbine blades of type A and B engines.Some methods for elimination of the cracked failures of fir-tree serration in the turbine disc are provided.According to the experiece in service,a modification of type B engine hase eliminated the cracked failures of fir-tree serration of turbine disc in its service life.
