Synthetic Characterization and Evaluation of Mechanical Properties for Airframe Metal Based on Damage Tolerance Design

The airframe material selection criterion has paid more attention to the damage-tolerant properties with the establishment of durability and damage-tolerance design principle.Considering the actual bearing stress,the damage-tolerance properties can be characterized by the da/dN-3ΔK/σb curves during crack stationary propagation stage.The damage tolerance properties of the airframe metals are compared by using this method.The compared results show that this characterization could characterize the damage-tolerance properties of materials more comprehensively.The curves of stress vs.total fatigue life and crack propagation are plotted to evaluate the synthetic mechanical properties,and to enhance the accuracy of materials selection.On the other hand,the relationship between material properties and design requirements are established through these curves,this could guide the new material research and development.