Method for establishing aero-engine load spectrum mixed distribution model related to use

Abstract

The invention discloses an aero-engine load spectrum hybrid distribution model building method related to use. The method comprises the following steps of: firstly, dividing a take-off section, a middle section and a landing section of normal overload and rotation spectrums of all flight mission profiles; splicing all the sections and the middle sections of all the maneuvering sections to obtain aspliced spectrum and a maneuvering middle section spliced spectrum; performing statistical analysis on all profile splicing spectrums, and determining that normal overload has a thick tail characteristic through thick tail detection; secondly, extracting normal overload coefficient values corresponding to the 100% rotating speed position in the maneuvering middle section spliced spectrum to serveas a threshold value database, and adopting the normal overload coefficient value with the highest occurrence frequency in the threshold value database as the threshold value of the normal overload coefficient mixed distribution model of the aero-engine; finally, defining normal overload coefficients greater than a threshold value in all the profile splicing spectrums as extreme value loads, anddefining normal overload coefficients lower than the threshold value in all the profile splicing spectrums as medium and low loads to obtain mixed distribution of the medium and low loads and the extreme value loads.

Description

technical field [0001] The invention belongs to the technical field of aero-engine load spectrum data statistics, and in particular relates to a method for establishing a mixed distribution model of an aero-engine load spectrum related to use. Background technique [0002] The load borne by aeroengine components in actual flight changes continuously and randomly, and the load-time curve of a flight mission is the aeroengine load spectrum. The engine load spectrum records the proportion and magnitude of the aerodynamic, thermal, and mechanical loads borne by the aeroengine in actual use. Its main parameters include flight altitude, engine speed, gas temperature after the turbine, or engine throttle lever angle, etc. The load spectrum runs through the engine safety assessment and actual use, so the load spectrum plays an important role in the engine design, test and life determination process. [0003] Parameters such as altitude, speed, rotational speed and normal overload c...

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Problems solved by technology

[0004] Due to the technical blockade, it is difficult to consult foreign literature on the distribution of extreme loads of normal overload, and there are few domestic literatures on the distribution of extreme loads of normal overload. The extreme load studied in "([J]. Mechanical Strength, 2018(1)) is the peak load in the normal overload spectrum, and the expression of the probability density function of the Pearson-Ⅲ distribution is relatively complicated and difficult to apply in practice

For the distribution of the extreme load of the overload factor spectrum in other literatures, most of them analyze the data based on statistics, and the selection of the threshold depends on the experience and knowledge level of the researchers, which is highly subjective.

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