Buckling of delaminated bi-layer beam-columns

Abstract

a b s t r a c tAn improved analytical model is presented to analyze the delamination buckling of a bi-layer beam-column with a through-the-width delamination. Both the transverse shear deformation and local delamination tip deformations are taken into consideration, and two delaminated sub-layers as well as two substrates in the intact (un-delaminated) regions are modeled as individual Timoshenko beams. A deformable interface is introduced to establish the continuity condition between the two substrates in the intact regions. Consequently, a flexible joint is formed at the delamination tip, and it is different from the conventional rigid joint given in most of studies in the literature, in which the local delamination tip deformations are completely ignored. In contrast to the local delamination buckling in our previous study , the present model accounts for the global deformations of the intact region in the delaminated composite beam-column, thus capable of capturing the buckling mode shape transitions from the global, to global-local coexistent, and to local buckling for asymmetric delamination as the interface delamination increases. Good agreement of the present analytical solutions with the full 2-D elastic finite element analysis demonstrates the local deformation effects around the delamination tip and verifies the accuracy of the present model. Parametric studies are conducted to investigate the effects of loading eccentricity, delaminated sub-layer thickness ratio, and interface compliance on the critical buckling load for the delaminated composite beam-column. Transitions of buckling modes from the global to local delamination buckling are also disclosed as the thickness of one sub-layer reduces from the thick sublayer to a thin film. The developed delamination buckling solution facilitates the design analysis and optimization of laminated composite structures, and it can be used with confidence in buckling analysis of delaminated composite structures.

Critical buckling load of composite laminates containing delamination using differential quadrature method and ABAQUS finite element

“…Delamination could inevitably occur due to manufacturing procedure mistakes, in-service mishaps and excessive operational loads. 8 Many researchers, therefore, have broadly investigated delamination as an important failure mode in composite laminates. Qiao et al 9 used novel joint deformation models to study the local delamination buckling of laminated composite beams.…”

Dynamic analysis of composite beams with weakshear connection subjected to an axial load

“…The elastic stability problems of composite beams with weak shear connection were also investigated [12,13,14,15,16]. Challamel and Girhammar [12] analysed the lateral-torsional stability of vertically layered composite beams with interlayer slip based on a variational approach.…”

“…Challamel and Girhammar [12] analysed the lateral-torsional stability of vertically layered composite beams with interlayer slip based on a variational approach. An analytical method was presented for the delamination buckling using the Timoshenko beam theory by Chen and Qiao [13]. Grognec et al [14] utilized the Timoshenko beam theory as well.…”

An ultimate-state-based-model for inelastic analysis of intermediate slenderness PSB columns under eccentrically compressive load

“…However, the reliability-based design approach for PSB structures, even for timber structures, are less advanced than for concrete and steel structures due to the ultimate state of PSB or timber structures have not yet to be well understood. Some studies associated with the nonlinear buckling analysis of wood or other fibrous columns had been reported in the recent years [12][13][14][15]. The loading-carry capacity analysis for eccentrically loaded wood or bamboo columns, however, were deficiently disused.…”