An enhanced virtual element formulation for large displacement analyses is presented. Relying on the corotational approach, the nonlinear geometric effects are introduced by assuming nodal large displacements but small strains in the element. The element deformable behavior is analyzed with reference to the local system, corotating with the element during its motion. Then, the large displacement-induced nonlinearity is accounted for through the transformation matrices relating the local and global quantities. At the local level, the Virtual Element Method is adopted, proposing an enhanced procedure for strain interpolation within the element. The reliability of the proposed approach is explored through several benchmark tests by comparing the results with those evaluated by standard virtual elements, finite element formulations, and analytical solutions. The results prove that: (i) the corotational formulation can be efficiently used within the virtual element framework to account for geometric nonlinearity in the presence of large displacements and small strains; (ii) the adoption of enhanced polynomial approximation for the strain field in the virtual element avoids, in many cases, the need for ad-hoc stabilization procedures also in the nonlinear geometric framework.

提出了用于大位移分析的增强虚拟单元公式。依靠共旋转方法，通过假设单元中节点大位移但小应变来引入非线性几何效应。参考局部系统分析单元的变形行为，在单元运动过程中与单元共同旋转。然后，通过与局部和全局量相关的变换矩阵来解释大位移引起的非线性。在局部层面，采用虚拟单元法，提出了单元内应变插值的增强程序。通过几个基准测试，将结果与标准虚拟元素、有限元公式和解析解评估的结果进行比较，探讨了所提出方法的可靠性。结果证明：（i）共旋公式可以在虚拟单元框架内有效地使用，以解决大位移和小应变存在下的几何非线性；(ii) 在许多情况下，对虚拟单元中的应变场采用增强的多项式近似可以避免在非线性几何框架中也需要临时稳定程序。