This paper introduces for the first time the concepts of non-coherent interfaces and microstructure-driven interface forces in the framework of micromorphic elasticity. It is shown that such concepts are of paramount importance when studying the response of finite-size mechanical metamaterials at the homogenized macro-scale. The need of introducing interface forces is elucidated through numerical examples comparing reduced relaxed micromorphic simulations to their full-microstructured counterparts. These results provide a milestone for the understanding of metamaterials’ modeling at the homogenized scale and for the use of micromorphic-type models to achieve an accurate upscaling towards larger-scale metamaterials’ structures.

中文翻译：

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有限尺寸机械超材料的简化松弛微形态建模中的有效表面力和非相干界面

本文首次在微形态弹性框架下引入非相干界面和微结构驱动的界面力的概念。研究表明，在研究均匀宏观尺度上有限尺寸机械超材料的响应时，这些概念至关重要。通过将简化的松弛微形态模拟与全微结构模拟进行比较的数值示例，阐明了引入界面力的必要性。这些结果为理解均质尺度的超材料建模以及使用微形态模型实现更大规模超材料结构的精确升级提供了里程碑。