Structural Damage Detection by Using Finite Element Method as Function of Length

The work described in this paper involves the effect of length and fibre orientation of the composite damping for comparison with the analytical results. The calculation of laminate damping is performed by use of a strain energy method. The modal analysis of the structure for different loading rates is based on the analytical method used to solve the equation of free vibrations. The difference between strain energies for both cases (damaged and undamaged) are calculated by the finite element method. The structural damping of the different beams is evaluated from these energies. The decrease in frequency for different rates of loading shows the loss of stiffness for all lengths studied