Dynamics analysis of rotating soft core sandwich beams using the absolute nodal coordinates formulation with zigzag theory

With the widespread use of rotating sandwich structures in engineering applications, it is significant to understand their vibration characteristics and dynamic behavior. Since the absolute nodal coordinates formulation (ANCF) is one of the most effective methods for solving rotational dynamics, it is feasible to use the ANCF with zigzag theory (ANCF-ZZ) to analyze the dynamics of these structures. Therefore, this study builds upon existing research to further refine the theory of ANCF-ZZ and proposes diverse models for determining the element complexity required in modeling rotating sandwich structures. In order to better solve the dynamics of rotating sandwich beams, the ANCF-ZZ is described in a floating coordinate system by coordinate transformation. Subsequently, the dimensionless frequency and dynamic responses of rotating sandwich beams are analyzed, and the influence of core-to-face elastic modulus ratio and thickness ratio on them are investigated. The results show that the segmental description of the cross-section based on the zigzag theory is more influential than the warping description by higher-order interpolating polynomials. Consequently, reducing the order of original high-order ANCF-ZZ beam elements can improve computational efficiency without affecting accuracy. In addition, the ANCF-ZZ captures the dynamic stiffening effect and frequency veering phenomena, which are essential characteristics in rotational frequency analysis. Compared with commercial finite element software, the ANCF-ZZ not only can accurately analyze the dynamic stiffening effect of rotating sandwich beams but also can obtain the deformation response at non-constant rotational speeds and higher rotational speeds using a few elements, which is valuable for engineering applications.