Equivalent micropolar beam model for spatial vibration analysis of planar repetitive truss structure with flexible joints

An equivalent micropolar beam modeling method for spatial vibration analysis of planar repetitive truss structures with flexible joints was presented. Firstly, by modeling each joint as a connection element comprising spring-dampers in six axes, a two-node hybrid joint-beam element was derived for the member with flexible end joints based on the kinematic relationship and the dynamic equilibrium between the member and the joints. Then, by using the micropolar continuum theory and considering the effect of warping torsion, a high-precision kinematic assumption for the deformation of the planar repeating element was presented. At last, an equivalent micropolar beam model was obtained for the planar truss structure based on the energy equivalence method. In the numerical example, the frequency response functions (FRFs) of the truss structure with different boundary conditions are evaluated, and a thorough comparison of the results of the equivalent micropolar beam model, the equivalent classical beam model and the full finite element model was made. The results demonstrated the high accuracy of the equivalent micropolar beam model.