Numerical Investigation Of Quantitative Mode Shape Curvature As A Damage Diagnostic Technique

There is a strong requirement to develop effective techniques for structural health monitoring, so thatthe safety and integrity of the composite structures can be improved.To investigate the dynamics-based damage detection techniques of composite materials, bothexperimental and computational studies of the static and vibration behavior of composite beamscontaining delaminated damage of varying lengths are presented. The samples are subjected to purebending, free end shearing, free vibration and forced vibration at several frequencies respectively.Under the vibration behavior the displacement and acceleration were measured with the scanninglaser Doppler vibrometer. Finite element analysis is carried out with ABAQUS6.9.1and the resultsare compared with the experimental observations. The experimental and numerical curvature modeshapes are primarily used to detect the presence, location, and size of the damages.Two relatively new damage detection algorithms (i.e.,3rdDerivation Dimension (3DD), Angularfrequency method (AFM)) are employed to analysis the experimental and numerical displacementdata and determine the location of delaminates. From the data analysis, it is observed that the AFMmethod proves to be more convenient and effective, not only for the detection delaminations but otherkind of damages also, and it is capable to quantitative decide the damaged regions’ location, stiffnessand some other physical properties by acquire the angular frequency form the curve-fitted dynamicresponse results. Meanwhile, the3DD method also exhibits good sensitivity to delaminated damagedetecting which theoretically can decide which two layers the delamination exist.