METHOD OF FATIGUE EVALUATION FOR HELICOPTER COMPOSITE BLADE

摘要

PURPOSE: A fatigue estimation method of a composite blade of a helicopter is provided to estimate a safe life by applying defects and impact to a blade. CONSTITUTION: A fatigue estimation method of a composite blade of a helicopter is as follows. A detail finite element model is designed by using the geometrical and material information of blade parts (S100). Static stress and dynamic tension are generated by applying a load spectrum to the designed detail finite element model (S200). Fatigue damage is calculated by applying a coupon tension-collection diagram to the generated static stress and dynamic tension (S300). A safety life is estimated by using the calculated fatigue damage (S400). A fatigue property is produced by testing components to verify interfacial delamination and geometrical effects (S500). A safety diagram value is obtained by using the produced fatigue property to compensate the coupon tension-collection diagram (S600). A tolerant flaw safety life is obtained from the analysis and estimation to which the load spectrum measured by a flight test is applied (S700). [Reference numerals] (AA) Designing step; (BB) Proof step; (CC) Load spectrum; (DD) Information about the geometry of components, information about the materials of components; (EE) Component test; (FF) Flight test; (GG) Fatigue character characteristics; (HH) Fatigue limit; (II) Dispersion coefficient; (JJ) Number of tests; (KK) Spectrum of a measured load; (LL) Coupon stress-collection diagram; (MM) Safety diagram; (NN) Interpretation and evaluation; (S100) Detailed finite element model; (S200) Static stress, dynamic stress; (S300) Fatigue damage calculation; (S400) Safety life span expectation; (S600) Stress-collection diagram correction; (S700) Allowable defect safety life span