In recent years, the composite material has earned a lot of interest due to its diversified and potential application in civil, aerospace, and other industries. However, these materials are highly susceptible to hidden flaws such as delamination, fibre breakage, etc. That may arise due to mechanical damage and service-related defects caused by fatigue, the impact of foreign bodies, or other unexpected events. These defects may grow to a critical size, which becomes unstable, causing the entire structure's catastrophic failure. This will show a completely different behaviour of the structure, so it becomes necessary to study this characteristic.

Buckling characteristics of laminated composite panel subjected to in-plane edge loading and vibration behaviour of laminated/ delaminated T-stiffened plate subjected to the in-plane edge load is studied by using the Finite Element technique. The 9-noded isoparametric heterosis plate elements have been used to model the panel and the stiffener’s flange, and the 3-noded isoparametric beam element is used to model the web of the stiffener.

Apart from the study related to static stability and vibration problem, a study will be conducted to assess and quantify the damage in the delaminated stiffened plate by using the vibrational approach.

  Apart from the static stability and vibration study, ultrasonic guided wave techniques offer an accurate and efficient procedure for damage monitoring in the structures. To develop reliable damage monitoring systems, it is essential to have a thorough understanding of ultrasonic guided waves' quantitative nature that can be transmitted in composite laminates.

In this work, the Semi-Analytical Finite Element (SAFE) method is employed due to its efficiency in the treatment of wave propagation problems involving complex materials and geometry. A SAFE method is considered for the analysis of guided waves' dispersion behaviour in composite laminates by accounting for the in-plane load effect. The present study considers an infinite width plate such that the cross-section of the waveguide is modeled using 3 noded isoparametric 1-D elements representing the plate's thickness. The equation of motion is formulated by using Hamilton’s equation.

Apart from the study related to understanding the dispersive behaviour of the wave in the prestressed panel, a study will be conducted to assess and quantify the damage in the delaminated stiffened plate by using the indices.