The Effect of Warping Stress on the Lateral-Torsion Buckling of Cold-Formed Zed-Purlins

An analytical model is developed for analysing the elastic lateral-torsion buckling of cold-formed zed-purlins with partially lateral restraint from metal sheeting. The model is used to estimate the effects of warping stresses on the lateral-torsion buckling behavior of cold-formed zed-purlins with various boundaries and interval braces provided by antisag bars. The results show that the warping stress only has remarkable influence on the lateral-torsion buckling when the boundary of the member is fixed and there is no antisag bar present.

Download Full-text

Analysis of Delaminated Composite Plates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.686.104 ◽

2013 ◽

Vol 686 ◽

pp. 104-108

Author(s):

Ali Mahieddine ◽

Mohammed Ouali

Keyword(s):

Finite Element ◽

Analytical Model ◽

Composite Beam ◽

Composite Structures ◽

Failure Modes ◽

Laminated Composite ◽

Composite Plates ◽

Published Data ◽

Shear Stresses ◽

Buckling Behavior

A mathematical model for plates with partially delaminated layers is presented to investigate their behavior. In this formulation account is taken of lateral strains. The principal advantage of the element is that it allows the modeling of delamination anywhere in the structure. The region without delamination is modeled to carry constant peel and shear stresses; while the region with delamination is modeled by assuming that there is no peel and shear stress transfer between the top and bottom layers. Numerical results of the present model are presented and its performance is evaluated for static problems. Laminated beams and plates are often used as primary load-carrying structures. However, the mechanical properties of composite materials may degrade severely in the presence of damage. One of the common types of damage modes in laminated composites is delamination. The presence of delamination is one of the most prevalent life-limiting failure modes in laminated composite structures. Many researchers had been studying the effect of delamination. Wee and Boay [1] developed an analytical model to predict the critical load of a delaminated composite laminated beam. Lee et al. [2] investigated the buckling behavior of the beam plate with multiple delaminations under compression. Kapania and Wolfe [3] examined the buckling behavior of a beam plate with two delaminations of equal length. Wang et al. [4] improved the analytical solution by including the coupling between the flexural and axial vibrations of the delaminated sub-laminates. Lee et al. [5] studied a composite beam with arbitrary lateral and longitudinal multiple delamination. Finite-element methods have been developed using the layerwise theory by Kim et al. [6]. Tan and Tong [7] developed a dynamic analytical model for the identification of delamination embedded in a laminated composite beam. To investigate the effects of delamination of a plate layers, a finite-element model is developed. Both displacement continuity and force equilibrium conditions are imposed between the regions with and without delamination. The accuracy of the approach is verified by comparing results with previously published data.

Download Full-text

Investigation on buckling behavior of laminated glass columns with elastic lateral restraint under axial compression

Composite Structures ◽

10.1016/j.compstruct.2021.114810 ◽

2021 ◽

pp. 114810

Author(s):

Xiaokun Huang ◽

Shukun Duan ◽

Qiang Liu ◽

Jianguo Nie ◽

Weitao Han

Keyword(s):

Axial Compression ◽

Laminated Glass ◽

Buckling Behavior ◽

Glass Columns ◽

Lateral Restraint

Download Full-text

Analytical and Numerical Analyses of Delamination Buckling in Layer Beams

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.111.75 ◽

2006 ◽

Vol 111 ◽

pp. 75-78

Author(s):

Madusudhanan R. Parlapalli ◽

Dong Wei Shu ◽

G.B. Chai

Keyword(s):

Numerical Analysis ◽

Analytical Model ◽

Parametric Study ◽

Slenderness Ratio ◽

Numerical Analyses ◽

Ansys Software ◽

Buckling Mode ◽

Buckling Behavior ◽

Controlling Parameter ◽

Delamination Buckling

In the present paper, new nondimensionalized parameters, namely, nondimensionalized axial and bending stiffnesses have been introduced to study analytically the buckling behavior of two-layer beams with separated delaminations. Numerical analysis has been carried out by using ANSYS software to validate the developed analytical model. Delaminations are modeled with gap elements in ANSYS. A detailed parametric study has been carried out and it is found that the buckling behavior strongly depends on these new nondimensionalized parameters. Another nondimensionalized parameter, effective-slenderness ratio is also introduced and it is found to be a controlling parameter of delamination buckling mode configurations.

Download Full-text