| Tenon-mortise joint structure is widely used in the aero engine. Because firtree tenon-mortisestructure has many advantages, it is often used in connecting turbine disc and blade. While it hascomplicated shape and it is subjected to complex loads which causes severe stress concentration,Tenon-mortise joint structure often malfunction. So it is important to study the structure form andeffective design method of firtree tenon-mortise structure.(1) Design criterias were chose from EGD-3stress standard for firtree tenon-mortise structure.All the parameters were obtained for each structure, which were necessary to build the models. Somerelationships of design parameters were studied, and many formulas were deduced based on designcriterions and geometric harmony relationships, which were used for calculating associated designparameters of each structure. Analysis was undertaken to account for the effects of independent designparameters upon the resulting stress in virtual of the finite element method (FEM), which formedtwo-teeth and three-teeth firtree tenon-mortise structure engineering design method.(2)Validation design was undertaken, and new joint structures were obtained. Static strength andfatigue life assessment was taken on new structures and prototypes. Conclusions revealed that the newstructures have more strength storage and longer service life than the prototypes and the designmethod in this paper is reasonable and feasible.(3) The stress concentration area was also improved. The single arc connection was changed todual arc connection. Optimization design models and methods were established for two-teeth andthree-teeth firtree tenon-mortise structure. Equivalent stress minimization was selected as theoptimization objective and dual arc radii were selected as design variables. Using ISIGHT platform tointegrate UG and ANSYS, optimized design was taken on arc radius. The optimal structure greatlyreduced the maximum equivalent stress of stress concentration area. |
PDF Full Text Request