Free vibration theory of inhomogeneous anisogrid stiffened cylinder

摘要

With the requirement of stronger, stiffer, and lighter rocket interstage barrels, an inhomogeneous carbon fiber reinforced composite (CFRC) anisogrid stiffened cylinder (ASC) was designed and manufactured. A free vibration theory (FVT) was proposed to predict the free vibration behavior of the CFRC ASC with the help of energy method. Free vibration behavior of the CFRC ASC was tested. Based on the modal testing and the FVT, a nondestructive vibration correlated technique (VCT) was developed to identify the material property of the CFRC ASC. The fiber volume fractions (FVFs) of the skin, anisogrid and flange, which can be determined by the VCT, were selected as the key factors. The VCT based on finite element modeling (FEM) was constructed to validate the accuracy of the theoretical method. Following the developed method, the FVF of the skin of the manufactured cylinder is 43.5 and the elastic properties of the CFRC can be calculated.