Study On Strength Calculation Methods Of Bolt Connected Thin-wall Casing Structure

Aero-engine casing is the main thrust passed bearing parts, also form the maincomponents of the engine air flow channel, its complex structure and to withstand a variety ofloads. In the modern aero-engine casing design, the design of the casing as a light, thin form,the maximum increase engine thrust to weight ratio. However, in the case shell under load andthe effect of fatigue cracks easily, so the design must meet the strength requirements of thestructure. In this paper, thin-wall casing structure for the bolt connection strength calculation,calculation of the strength of the study.First, this paper studies typical bolt connection structure strength calculation, modalanalysis and modal experiment to study the different connection types of bolt connectionstructure in strength, vibration implications. Secondly, study the strength calculation methodsof bolt connected thin-wall casing structure. Stress calculation analytical method, the integralfor the three dimensional finite element strength calculation method and the cyclic symmetricstructure strength calculation method are used respectively to calculate integral thin-wallcasing strength, from the calculation results compared the cyclic symmetric structure strengthcalculation results and the three dimensional finite element strength calculation result is veryclose; Then used driven by target optimization method to optimize integral thin-wall casing,the maximum equivalent stress reduced by8.4%after optimization, the quality was reducedby1.75%, and the minimum safety factor of1.03%; Stress calculation analytical method, thesplit for the three dimensional finite element strength calculation, the strength of the split forthe two-dimensional finite element method are used respectively to calculate the openthin-wall casing strength, compared the results, the two-dimensional finite element methodinstead of the three dimensional finite element strength calculation can be well simulated withlongitudinal side bolt coupling installation on the thin-wall casing stress in most area; Finally,the finite element model of bolt connection structure is simplified, the original entity modelsimplified into a mixed bolt structure model. In order to verify the simplified method can be applied to the bolt connection thin-walled casing structure on the strength calculation, entitymodel of original bolt connection with transverse(vertical) edge thin-wall casing structure toreplace mixed bolt structure, the new strength calculation. Compared to two kinds ofcalculation results, the simplified calculation results and the calculation result of simplifiedbefore are close.