Usually, to mitigate the stresses in framed structures, different strategies are used. Among them, base isolation, viscous/friction/metallic yielding dampers and tuned mass dumpers have been widely investigated. Fluid Viscous Dampers (FVD) probably result the most diffused for the simplicity in the applications. However, these type of dampers request limited interstorey drifts to avoid dangerous effects. Further, they have an elevate cost. On the contrary, friction dampers are not so expensive but request high interstorey drifts to give a significant contribute in the dissipation of energy during an earthquake. In this paper an approach for the energy dissipation by friction, modified with respect to the usual one, is proposed. The device is a braking system borrowed from the mechanical engineering able to modulate its capability of dissipation, named Variable Friction Damper (VFD). Differently from the Constant Friction Damper, the VFD device investigated in this study provides a specific additional (variable) damping force with the increasing of the displacement. The feasibility of this braking system, the amount of energy that can be dissipated and the overall performances of structures equipped with this type of system are discussed in detail. Finally, dynamic performances of structures equipped with FVD are compared with those obtained by using VFD, highlighting the efficiency of the proposed device.

通常，为了减轻框架结构中的应力，使用了不同的策略。其中，基础隔离，粘性/摩擦/金属屈服阻尼器和调谐质量倾倒器已得到广泛研究。为了简化应用，流体粘性阻尼器（FVD）可能扩散最多。然而，这些类型的阻尼器要求有限的层间漂移，以避免危险的影响。此外，它们具有高昂的成本。相反，摩擦阻尼器并不是那么昂贵，但是需要较高的层间漂移，以在地震期间为能量的耗散做出重大贡献。在本文中，提出了一种通过摩擦对能量进行消散的方法，该方法相对于通常的方法进行了修改。该设备是从机械工程学借来的制动系统，能够调节其耗散能力，名为可变摩擦阻尼器（VFD）。与恒定摩擦阻尼器不同，本研究中研究的VFD装置随着位移的增加提供了特定的附加（可变）阻尼力。详细讨论了该制动系统的可行性，可耗散的能量以及配备这种系统的结构的整体性能。最后，将配备FVD的结构的动态性能与使用VFD获得的结构进行了比较，突出了所提出设备的效率。详细讨论了可以耗散的能量以及配备此类系统的结构的整体性能。最后，将配备FVD的结构的动态性能与使用VFD获得的结构进行了比较，突出了所提出设备的效率。详细讨论了可以耗散的能量以及配备此类系统的结构的整体性能。最后，将配备FVD的结构的动态性能与使用VFD获得的结构进行了比较，突出了所提出设备的效率。