Nanjing University of Aeronautics and Astronautics

Xuming Niu

Yingdong Song

Xu Zhao

Yaning Chang

Qiuhong Peng

Zhigang Sun

Mofei Chen

Disclosed is a method for structural damage monitoring for whole-machine life test of small turboshaft engine, comprising: determining a failure mode based on load borne by typical components of the small turboshaft engine in a service process and common failure forms, screening a structural damage index of a non-major component based on a coupling relationship between structural damages, selecting a destructive damage of components in the small turboshaft engine and an indirect damage causing changes in material properties of key component, planning a structural damage monitoring means based on the failure mode, the structural damage index, the destructive damage, and the indirect damage, designing an accelerated mission test platform of the small turboshaft engine, and designing a torque automatic loading scheme of an eddy current dynamometer, and testing the small turboshaft engine, and performing damage monitoring of the small turboshaft engine based on the planned structural damage monitoring means.

Methods for structural damage monitoring for whole-machine life test of small turboshaft engines

Disclosed is an equivalent acceleration method of creep loads based on a consistent failure mode. The equivalent acceleration method includes obtaining corresponding tensile strengths; obtaining corresponding creep rupture time; establishing rupture time law, minimum creep rate law and rupture strain law; calculating the value of parameter p in creep damage accumulation model; and dividing the failure mode consistency interval of creep load under variable temperature and variable load. The damage caused by the creep load in the failure mode consistency interval is calculated by using the multi-grade variable temperature and variable load creep nonlinear damage accumulation model, the damage is accelerated to the maximum creep load state in the failure mode consistency interval according to the principle of damage equivalence, and finally the equivalent acceleration of creep load is realized.

Equivalent acceleration method of creep loads based on consistent failure mode

Disclosed is a method for compiling an equivalent acceleration spectrum of creep under variable temperatures and loads. The method includes following steps: respectively carrying out a material high-temperature tensile test, material high-temperature creep tests and creep tests under two-stage variable temperatures and loads, and calculating values of a parameter p in a creep damage accumulation model under two-stage variable temperatures and loads; based on a nonlinear damage accumulation model under multi-stage variable temperatures and loads, calculating a damage D caused by a multi-stage variable temperatures and loads creep load spectrum by utilizing values of parameter p; based on the principle of consistency of damage D, transforming the multi-stage variable temperatures and loads creep load spectrum into an equivalent acceleration spectrum of a first-order maximum creep load, and finally compiling the equivalent acceleration spectrum of creep under variable temperatures and loads.

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Nanjing, China

Xuming Niu