Abstract:

[Background] Commercial aero-engine needs to meet the requirements of airworthiness safety, in which the fan blade shedding load must be considered in the design. Transient explicit dynamic analysis of engine is an effective analysis tool, but there are some contradictions in model scale, calculation efficiency and calculation accuracy. Generally, the whole machine model can provide more accurate component interface load by selecting appropriate parallel computing strategy. However, for the stress analysis of single component, the grid density is not enough to obtain satisfactory results. [Methods] The sub-model technology for whole engine transient explicit dynamic simulation uses the simplified model of aero-engine to calculate the whole machine. The load of parts is output through the pre-set sub model boundary, which is used as the input of dynamic strength analysis of the fine model of parts. The calculation accuracy is guaranteed and the calculation efficiency is greatly improved. [Results] In this paper, a specific area of the plate is defined as a sub model through an example of an equivalent plate impact test of a casing. The calculation results show that the sub model method can obtain the same calculation results as the whole model with local refinement. At the same time, taking the aero-engine fan shaft as an example, the sub model technology is applied to the dynamic analysis of parts under the load of blade flying off, and the sub model analysis method of aero-engine transient explicit dynamic simulation is established, which can not only solve the problem of large calculation error of the blade shedding equivalent load method for coarse grid component stress analysis, but also consider the influence of the microstructure of the components to the results of strength calculation.

Key words: aero engine, whole engine FBO analysis model, dynamic sub-model technology, parallel computing