Viscoelastic Cementitious Composites for Controlled Damping of Civil Infrastructure

本研究提出了水泥基材料设计技术和指导方针，具有上级粘弹性阻尼能力。 将创建一个分析建模框架，用于指导定制、受控粘弹性水泥基复合材料的多尺度设计。 基于分析模型，新的设计技术将利用材料科学和力学的战略整合，以优化多个长度尺度上的阻尼。 在纳米到微米尺度上，将利用水泥材料的孔隙力学行为来利用表观粘弹性来促进液压阻尼;这种效果类似于减震器的机制，因为阻尼将由流过小孔的压缩粘性流体提供。 在胶凝材料中，孔隙流体将被迫通过设计的、互连的孔隙网络以引起液压阻尼。 在毫米尺度上，新型粘弹性夹杂物与模型驱动的表面处理将被用来提高复合阻尼。 将进行实验以测量分析模型的关键参数，并验证模型预测阻尼。 关键参数测量将包括传统的性能，如孔隙率，孔隙连通性和模量，以及非传统的性能，如表面energy.If成功，这项研究的结果将使开发令人兴奋的新定制粘弹性水泥基复合材料的民用基础设施的应用。 这些新材料的主要作用将是作为综合能量吸收器，以减少地震，风，冲击，爆炸和其他结构振动源引起的损害。结构材料对阻尼的贡献可能是相当大的，这是由于结构中这种材料的巨大体积。 此外，这项研究将导致在粘弹性多孔固体的行为，在复合材料中的相相互作用，和流体-固体材料相互作用的理解的全面改善。

This research proposes to develop techniques and guidelines for designing cementitious materials with superior viscoelastic damping capacity. An analytical modeling framework will be created for guiding the multiscale design of customized, controlled viscoelastic cementitious composites. Based on the analytical models, the new design techniques will utilize strategic integration of materials science and mechanics to optimize damping on multiple length scales. On the nano through microscale, the poromechanical behavior of cementitious materials will be exploited to utilize apparent viscoelastic properties to promote hydraulic damping; this effect is analogous to the mechanism of a shock absorber in that damping will be provided by compressed viscous fluid flowing through small pores. In cementitious materials, the pore fluid will be forced through the designed, interconnected pore network to invoke hydraulic damping. On the millimeter scale, novel viscoelastic inclusions with model driven surface conditioning will be utilized to improve composite damping. Experiments will be performed to measure parameters critical to the analytical models, and to validate the model predicted damping. Critical parameters to measure will include traditional properties such as porosity, pore interconnectivity, and moduli, as well as nontraditional properties such as surface energy.If successful, the results of this research will enable the development of exciting new tailored viscoelastic cementitious composite materials for civil infrastructure applications. The primary role of these new materials will be to serve as integrated energy absorbers to reduce the damage induced by earthquakes, wind, impacts, blasts, and other sources of structural vibrations. The contribution of structural materials to damping may be considerable, owing to the tremendous volume of such materials in a structure. Additionally, this research will result in an overall improvement in the understanding of the behavior of viscoelastic porous solids, phase interaction in composite materials, and fluid-solid material interaction.