Anti-fatigue optimization of the twisting force arm of landing gear based on Kriging approximate sequential optimization method

ABSTRACTThe twisting force arm (TFA) is an important part of the pillar landing gear, anti-fatigue optimization on its structure can improve the reliability of the landing gear. However, the optimization accuracy of the conventional optimization method is limited by the basic topological structure from the views of topological theory. Besides that, the optimization efficiency of the conventional method is also relatively low because of the high computational cost of the fatigue life estimation. In this paper, an anti-fatigue optimization method of the TFA was developed to improve the optimization accuracy and efficiency by using the approximate sequential optimization method after an optimal basic topological structure was obtained. To verify its effectiveness, the proposed method was introduced to the anti-fatigue optimization of a pillar landing gear TFA. The results show that the optimization accuracy of the proposed method is higher than the conventional method, and the computational cost can be reduced 82.35%. This indicates that the proposed method can improve the optimization accuracy and efficiency of the anti-fatigue optimization.CO EDITOR-IN-CHIEF: Jeng, Yeau-RenASSOCIATE EDITOR: Jeng, Yeau-RenKEYWORDS: Twisting force armlanding gearKrigingfatigue lifesequential optimization Nomenclature Dj=accumulative fatigue damage under the jth stage loadG0=weight of the TFA after topological optimizationG=weight after anti-fatigue optimizationNj=number of the stress cycles when the failure occurs under the jth stage loadN=fatigue life of the TFAnj=number of the stress cycles under the jth stage loadSE=total strain energy of the design domainSa=stress corresponding to the TFA Sa-N curveTFA=twisting force arm of the pillar landing gearxk=element density in the design domainxi=design variablesximin=low bounds of the design variablesximax=up bounds of the design variablesγ=scatter factor that considering the dispersion of the fatigue lifeωj=ratio that the number of the jth stage stress cycles to the gross number of the stress cyclesσa=stress corresponding to the material S-N curveσmax=maximum Von-Mises stressDisclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the Natural Science Basic Research Plan in Shanxi Province of China, grant number: 2022JM-213, 2022JQ-412, 2021JQ-874.