Research On Damping Characteristic Of Composite Lattice Sandwith Structures

Structure damping integration technology can achieve highly efficient vibrationcontrol and the structure function integration, it is an important research directionfor the structural design of aerospace vehicles.Based on the all-composite latticesandwich structure which has excellent specific stiffness and strength properties,combined with high damping characteristic of viscoelastic material, this thesisdesignes and fabricates the multi-functional structure which both has structuralbearing function and noise and vibration reduction function, then systematicallystudies the dynamic response and damping characteristic of such structures throughthe damping experiment with the theory of modal analysis and modal strain energymethod,on this basis, optimizes the damping characteristics and studies the steady-state response of the structure which provides a theoretical guidance and technicalsupport for the design of new structural damping integrated structure.Firstly, the damping capacity of carbon fiber reinforced epoxy composite wasanalyzed through the experiment combining the numerical calculation method, onthis basis, studies the first three natural frequencies and damping loss factors ofcomposite laminates,analysis the damping mechanism and discusses the impact ofdifferent fiber ply angle to its natural frequencies and damping properties.For the composite lattice sandwich panels, studies the first three naturalfrequencies and damping loss factors of the structure by two ways of modalexperiment and numerical prediction, analysis and compares the dampingproperties with the steel, aluminum damping honeycomb panels. And then obtainsthe best damping effect of the structure which filled with high damping materialsby optimizing the thickness ratio of the panels and studies its steady-state response.For the composite lattice sandwich cylinder, a method combining experiment andfinite element numerical prediction is developed for its damping research.Thendiscuss the optimal allocation of the structural damping loss factors from the formsof ply angle.