| This thesis reviewed the development of aircraft structural fatigue life design ideas andintroduced the significance and technical approach of life monitoring on single plane. A loadinversion method for life estimation based on physical prototype was proposed to solve the problemsin life monitoring on single plane.The inversion method based on physical prototypes was elaborated, including the definition ofthe physical prototypes and mathematical explanation of inversion. Specimens with a centered holeunder different loads were tested，which show the feasibility and effectiveness of the proposedmethod. Furthermore，two problems of the fatigue life inversion method based on physical prototypeswere presented—and measure points selection.For the complex load inversion: Parameters decoupling was necessary. Different direction andsize of load were decoupled by normalization and inversed by using SVM and FEM. A test pieces oflug and corresponding fixtures were produced specially. Then11groups of load inversion test andfatigue life test were carried out. Results show that calculated values are in good agreement with theexperimental value, which show the feasibility of the fatigue life inversion method based on physicalprototypes.For the selection of the measuring points: Selection principles of the measuring points wereintroduced simply, and standard measuring points were proposed. Spot for multiple connectionsFatigue test of spot-welded joints were carried out and results show that calculated values are in goodagreement with the experimental value, which proved that the measuring points parametric not onlyimproves the universality of the model, but also simplifies the inversion process greatly. Furthermore,it shows the feasibility of the fatigue life inversion method based on physical prototypes. |
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