Stability Analysis of Variable Stiffness Composite Laminated Plates with Delamination Using Spline-FSM

Abstract

The dynamic behavior of variable stiffness composite laminated (VSCL) plate with curvilinear fiber orientation subjected to inplane end-loads is investigated. A variable stiffness design can increase the laminated composite structural performance and also provides flexibility for trading-offs between various structural properties. In each ply of the VSCL plate, the fiber-orientation angle assumed to be changed linearly with respect to horizontal geometry coordinate. The spline finite strip method based on both classical as well as higher order shear deformation plate theories is formulated to explain the structural behavior. The panel is assumed containing internal square delamination regions with friction and contact conditions at delaminated interfaces are not considered. In order to demonstrate the capabilities of the developed method in predicting the structural dynamic behavior, some representing results are obtained and compared with those available in the literature. The effects of change in curvilinear fiber orientation angles on the structural stability is studied. The obtained results show very good conformity in comparison with those exists in the available literature.

Panel flutter of curvilinear composite laminated plates in the presence of delamination

“…The force resultants ( N, M ,O,P,Q,R,T,U ) in energy integrands are location dependent due to change in the fiber orientation angles of curvilinear plies on any layers and may be related to the local strain terms via the curvilinear fiber laminated material equivalent stiffness matrices through 13 …”

“…The changing fiber angle is denoted by a two-angle set <T 0 , T 1 > where the former one and the latter are the fiber angle at the plate middle section and plate ends, respectively. 13 Figure 2(b) depicts the pattern of changing fiber orientation in longitudinal direction. The fiber angle at every arbitrary point in the geometry surface could then be expressed by linear equation …”

“…The results revealed that fiber redistribution can efficiently increase flutter boundary. The author of this manuscript in his earlier works, 10–13 developed semi-analytical as well as spline finite strip formulations and investigated the dynamic instability problem of flat and curved shell panels with and without internal cutout, delamination, and longitudinal stiffeners under uniform in-plane loadings.…”

A simple spline finite strip for buckling analysis of composite cylindrical panel with cutout

“…Use of the Finite Strip Method (FSM) is simpler and more economical compared to the FEM, in order to analyze long thin-walled structures such as cylindrical panels (Mirzaei et al 2015, Fazilati 2017, Balogh and Logo 2015, Rondal 1998. Moreover, while in the FEM the structure is discretized in transverse and longitudinal directions, it is only discretized in transverse direction in FSM (Rondal 1998).…”

Dynamic instability of variable angle tow composite plates with delamination

“…All of the above research works focused on the study of dynamic instability of constant stiffness laminated plates or shells with delaminations. Fazillati [33] recently reported a research work that applied a B-spline finite strip method to study the dynamic instability behavior of variable stiffness composite laminated plates with delamination. However, the non-uniform in-plane stress field was not considered in his model and analysis.…”