A Two-Level Non-Intrusive Coupling Method for Fatigue Analysis

¹ AVIC the First Aircraft Institute, Xi'an, China
² Northwestern Polytechnical University, School of Aeronautics, Xi'an, China

^* Corresponding author: lyanjie1988@163.com

Abstract

concept and the continuum damage mechanics, a two-level non-intrusive coupling strategy for fatigue analysis procedure is developed to efficiently and accurately predict the fatigue damage of critical details in a large structure. Coupled multi-scale models including the global structure (coarse mesh) and local details (fine mesh) are involved to evaluate fatigue damage in local details and their effect on the global structure. In this method, the fatigue analysis in critical region is divided into two levels – the local boundary condition update and the local fatigue analysis. In the first level, the external cyclic load is transferred from global scale to the local scale. And in the second level, the local fatigue analysis driven by the local cyclic boundary is carried out. The computational procedure of this two-level analysis can be fully coupled, semi-coupled or uncoupled according to different scenarios. Furthermore, the low-cycle fatigue damage is studied and the corresponding fatigue life predictions are simulated on a plate with a central circular hole under cyclic load. The results reveal that the present method greatly improves the numerical efficiency and accords well with the traditional FE analysis with global fine mesh.