A Multi-Scale Submodel Method for Fatigue Analysis of Braided Composite Structures

Abstract

A multi-scale fatigue analysis method for braided ceramic matrix composites (CMCs) based on sub-models is developed in this paper. The finite element shape function is used as the interpolation function for transferring the displacement information between the macro-scale and meso-scale models. The fatigue failure criterion based on the shear lag theory is used to implement the coupling calculation of the meso-scale and micro-scale. Combining the meso-scale cell model and the fatigue failure criterion based on the shear lag theory, the fatigue life of 2D SiC/SiC is analyzed. The analysis results are in good agreement with the experimental results, which proves the accuracy of the meso-scale cell model and the fatigue life calculation method. A multi-scale sub-model fatigue analysis method is used to study the fatigue damage of 2D SiC/SiC stiffened plates under random tension–tension loads. The influence of the sub-models at different positions in the macro-model element on the analysis results was analyzed. The results shows that the fatigue analysis method proposed in this paper takes into account the damage condition of the meso-structured of composite material, and at the same time has high calculation efficiency, and has low requirements for modeling of the macro finite element model, which can be better applied to the fatigue analysis of CMCs structure.

Multiscale modeling on the multi-physical behaviors of high temperature superconducting magnets based on a combined global homogenization and local refinement scheme

“…Therefore, it is necessary to develop a new modeling scheme to accurately calculate the stress-strain distribution inside the HTS tape during the operation of HTS magnets. At present, the multiscale methods include the local mesh refinement method [29,30], the substructure method [31,32] and the sub-model method [33,34] have attracted much attention and been widely used in modeling the macro-and microscopic mechanical behavior of composite structures [35]. The sub-model method, which separates the areas that need to be focused on from the overall model, establishes refined modeling on the sub-model, and solves the overall model and the sub-model simultaneously [36,37], is one of the promising candidate to simulate the multiscale behaviors of HTS magnets.…”

“…The sub-model method, which separates the areas that need to be focused on from the overall model, establishes refined modeling on the sub-model, and solves the overall model and the sub-model simultaneously [36,37], is one of the promising candidate to simulate the multiscale behaviors of HTS magnets. The coupling between the overall model and the sub-model is realized by establishing interface between the macroscopic model and the microscopic model [35]. Therefore, the sub-model method can help to establish an accurate and efficient multiscale numerical model for the HTS magnet.…”