Delamination effects on the unsteady aero-elastic behavior of composite wing by modal analysis

Abstract

This article deals with the investigation of delamination effects on the flutter behavior of a composite wing subjected to unsteady aerodynamic loads by providing an integrated procedure using exact methods. For this purpose, an undamaged wing structure is modeled as a cantilevered Bernoulli–Euler beam with coupled bending–torsion and delaminated wing structure is modeled as three interconnected intact beams. The modal analysis of the intact and delaminated beams is performed and mode shapes are obtained based on the development of the dynamic stiffness matrix, a computer code and an iterative method. The fundamental modes of the intact and delaminated beam derived from the free vibration analysis are used in Galerkin’s method and the flutter and divergence speeds are obtained with aerodynamic forces applied. In fact, modified shape functions were developed to reflect the delamination effect in the aeroelastic analysis. Also, for the unsteady aeroelastic analysis, an iterative algorithm is developed. It was found that the delamination location and its length can have a positive or a negative influence on the flutter behavior of the wing which depends on the fiber angle.

Aeroelastic control of delaminated variable angle tow laminated composite plate using piezoelectric patches

“…The presence of delamination can have a positive and negative influence on the flutter and divergence velocity. 62 Based on the above literature survey, it is found that the presence of delamination can have disastrous effects on the aeroelastic response of the structures. Manufacturing defects are one of the major causes of delamination and the process involved in the manufacturing of composite plates with VAT laminates are much more complicated than constant stiffness laminates.…”

“…The presence of delamination can have a positive and negative influence on the flutter and divergence velocity. 62…”