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论文类型：期刊论文

发表时间：2012-10-01

发表刊物：PHILOSOPHICAL MAGAZINE

收录刊物：SCIE、EI、Scopus

卷号：92

期号：28-30,SI

页面范围：3723-3752

ISSN号：1478-6435

关键字：adaptive multiscale technique; strain localization; truss material; scale bridging

摘要：The numerical analysis of truss materials and structures often involves a huge number of degrees of freedom leaving the analysis intractable when using the traditional numerical methods. To reduce the computational costs and avoid the macroscopic grid sensitivity, an adaptive multiscale technique is developed for strain localization analysis of periodic lattice truss materials. With the evolution of microscopic state variables, the full macro-scale model is adaptively transformed into a multiscale model, where the localized zone is automatically detected and resolved on a fine-scale by the direct finite element method; at the same time, for the other subregions, the coarse-scale model is adopted and is resolved by the extended multiscale finite element method. To achieve computational efficiency, a displacement gradient-based mesh indicator is proposed for the adaptive scheme to identify the fine-scale subregions during the computational process. The two different scales are then bridged at the interfaces by means of the multiscale base functions, which are constructed numerically and can efficiently capture the small-scale features of a coarse element. Several typical numerical examples are calculated and the results are compared to the reference solutions to demonstrate the validity of the method proposed.