An Investigation into the Factors Affecting the Dynamic Performance of Steel/Wood Sandwich Beams

Abstract

Sandwich beams offer designers a number of advantages, such as high stiffness to weight ratio, high bending, and buckling resistances, ….etc. which are useful in aerospace, and mechanical engineering designs as well as in renewable-energy applications e.g. wind mill blades. In the present study the effects of the different sandwich beam parameters, such as; face and core thicknesses, beam width and length on the dynamic performance of steel/wood sandwich beams have been investigated as compared with a steel solid beam with the same dimensions. The damped-and undamped natural frequencies of the beams have been determined both theoretically and experimentally. The impulse excitation technique has been used to determine the frequency response. The present investigation has revealed that, the theoretical and experimental results are in a good agreement. The sandwich beam has shown higher stiffness-to weight ratio & higher damping capacity as well as higher damped-and undamped natural frequencies than the steel solid beam. The natural frequencies of the sandwich beam are increased by the increase of the beam thickness caused by the increase of the face layer thickness or the core thickness. On the other hand these frequencies are reduced by the increase of the beam length but are unaffected by the beam width. However it has been concluded that the selection of the optimum sandwich beam parameters depends on the application requirements.