Theoretical Investigation on Stiffness and Vibration Characteristics of Laminated Beams with Uniformly Vertical Displacement

The laminated beam with uniformly vertical displacement can be divided into contact region and separation region when bending deformation occurs. Friction between the interfaces will cause the stiffness inconsistency between the separation region and contact region. In this paper, calculation formula of section stiffness considering interface friction effect is derived. Assuming that the beam vibrates freely in equal wavelength and equal stiffness forms respectively, the calculating formulas of natural vibration frequencies of simply supported and cantilever beams are derived. Finally, based on a steel-concrete laminated test beam with uniform vertical displacement, the natural vibration frequencies of the beam are calculated. The conclusions are as follows: The derived formulas can calculate the natural vibration frequencies of laminated beams under different interface states effectively; The influence of friction effect on the vibration frequency of laminated beams becomes more and more obvious with the increase of the order.