Size-dependent dynamic responses of small-size frames are modelled by stress-driven nonlocal elasticity and assessed by a consistent finite-element methodology. Starting from uncoupled axial and bending differential equations, the exact dynamic stiffness matrix of a two-node stress-driven nonlocal beam element is evaluated in a closed form. The relevant global dynamic stiffness matrix of an arbitrarily-shaped small-size frame, where every member is made of a single element, is built by a standard finite-element assembly procedure. The Wittrick–Williams algorithm is applied to calculate natural frequencies and modes. The developed methodology, exploiting the one conceived for straight beams in [International Journal of Engineering Science 115, 14–27 (2017)], is suitable for investigating free vibrations of small-size systems of current applicative interest in Nano-Engineering, such as carbon nanotube networks and polymer-metal micro-trusses.

小型框架的尺寸相关动力响应通过应力驱动的非局部弹性建模，并通过一致的有限元方法进行评估。从解耦的轴向和弯曲微分方程开始，以封闭形式评估两节点应力驱动非局部梁单元的精确动态刚度矩阵。任何形状的小型框架的相关全局动态刚度矩阵都是通过标准的有限元组装程序构建的，其中每个构件都由单个元素组成。Wittrick–Williams算法用于计算固有频率和模式。[国际工程科学杂志115，14–27（2017）]中采用了一种针对直梁的方法，