In this work, we investigate a dynamic internal dissipation mechanism in the context of cement-based materials by introducing a 1D-enhanced micromorphic beam model with a dynamic internal friction term. Here, we consider an inherent feature in concrete-like materials arising from the multi-scale structure, namely, microcracks. Thus, we assume that the internal dissipation of the energy depends on the overall relative sliding displacement of the opposite faces in the microcracks under the effects of an applied cyclic load whenever no significant phenomena related to damage occur at the macroscopic level. The dynamic friction term is based on a well-known model for dry friction in solids due to P. R. Dahl, where the friction force depends only on the sliding displacement and evolves in time, reproducing an elastoplastic behavior. The model proposed in this paper takes into account a mechanical energy interchange between both bending and shear distortion in the beam with the sliding occurring at the microcracks, a storage of mechanical energy because of the asperities inside the faces of the microcracks, and the dissipation of the energy that follows from the interaction between the bending and the microcracks. Numerical simulations of the kinematic descriptors and the dissipative cycles are also provided by using the Finite Element Method and the commercial software COMSOL Multiphysics^®.

在这项工作中，我们通过引入具有动态内耗项的 1D 增强微形态梁模型，研究了水泥基材料背景下的动态内部耗散机制。在这里，我们考虑了由多尺度结构引起的类混凝土材料的固有特征，即微裂纹。因此，我们假设能量的内部耗散取决于在施加循环载荷作用下微裂纹中相对面的整体相对滑动位移，只要在宏观层面上没有发生与损伤相关的显着现象。动摩擦项基于 P. R. Dahl 提出的固体干摩擦的著名模型，其中摩擦力仅取决于滑动位移并随时间演变，再现了弹塑性行为。本文提出的模型考虑了梁中弯曲和剪切变形之间的机械能交换，滑动发生在微裂纹处，由于微裂纹表面内部的凹凸而导致的机械能存储，以及弯曲和微裂纹之间相互作用产生的能量耗散。此外，本文还使用有限元法和商业软件 COMSOL Multiphysics^® 提供了运动学描述符和耗散周期的数值模拟。