Numerical Investigations on Free Vibration Analysis of Delaminated Composite Plate

Abstract

Background: This research investigates the numerical evaluation of delamination effects on a composite laminate by analysing the size and location of delamination under various boundary conditions. Methods: The study employs modal analysis on an eight-ply composite laminate with the sequence (0/90/45/90) s using the Ansys Composite PrepPost (ACP) module. Initially, the natural frequencies and mode shapes of the undamaged composite laminate are validated against existing literature. Subsequently, deliberate damage is induced in the laminate to examine the influence of the size and location of the damage for different boundary conditions. Findings: The results reveal that the natural frequency of the plate is highest at the midplane and diminishes progressively towards higher interfaces. Furthermore, delamination significantly affects higher modes of vibration more than the fundamental mode. The research also explores the impact of varying degrees of restraint on the composite laminate, indicating that a higher degree of constraint leads to an increased natural frequency. Finally, a substantial difference of over 20% in natural frequency is observed between an intact plate and a damaged plate when the level of constraint on the plate is intensified. Novelty and applications: The novelty of this work lies in the innovative approach of utilizing Finite Element simulations through the ACP module. This unique method adds a fresh dimension to the study, enabling a more comprehensive exploration of the behaviour of composite laminates under delamination. The integration of ACP contributes to a deeper understanding of the intricacies involved, thereby enhancing the significance of the findings.