Curvature Modal Analysis of Defective Wood Beams Based on Finite Element Method

Wood is a kind of natural resource, and it has better strength and stiffness, so it is adapt to build wood structures, such as wooden bridge and building. However, wood is vulnerable to decay by all kinds of rot fungi, so it is need to find some effective methods to test the information of defect and evaluate the position and degree of defect. Finite element method (FEM) and experiment modal analysis (EMA) are used to obtain curvature modes of red pine standard specimen and hole-defect specimen with different sizes. Further analysis results of two methods show that curvature mode of defect part in wood always jumped abruptly to some extent, which is positive related to the size of the hole. Therefore modal analysis technology is proved to be accessible and feasible both in theory and in practice.