Effect of damage on the vibration modal of a novel three-dimensional and four-directional braided composite T-beam

The effect of damage on the modal properties of a three-dimensional (3Dim) and four-directional (4Dir) braided composite T-beam was investigated by means of modal experiments and finite element analysis (FEA). The experimental tests on these damaged T-beams showed alteration of the vibration mode response. The damage obviously changed the mode shape curvatures. The influence of the damage upon the modal shape curvatures of the T-beam could be used to detect and localize the damage. Finite element modeling (FEM) of the damaged T-beam revealed that the damage affected the natural frequency of the T-beam but did not affect its modal shape.